How to re-use default sequential filenames?

How to re-use default sequential filenames?

[Alan Hagge]

I'm trying to put together a test of the write and read speed to some 
new SAN storage.  Our workflow involves writing large numbers of 12 MiB 
files (on the order of 20,000 or so) at a time.  I'd like to set up a 
config file section that will write all 20,000 files then read all 
20,000 files and report on the write performance and the read 
performance (separately).

I've tried something like this:

[global]
blocksize=4m
filesize=12m
nrfiles=20000
openfiles=1
file_service_type=sequential
create_on_open=1
ioengine=posixaio

[write]
rw=write

[read]
stonewall
rw=read

But the issue is that the files get created with default filenames 
(write.1.1, write.1.2, etc.), so that when the read job is run, it can't 
find any files (since it expects the files to be named read.1.1, 
read.1.2, etc.).  If I try to specify the "filename=" option in either 
section, fio no longer appends the ".<thread>.<sequence>" to the 
filename, but rather tries to do all I/O to a single file.

Is there a syntax for the "filename=" option that will allow me to 
specify a different root filename, but still use the 
".<thread>.<sequence>" naming convention?  Failing that, is there any 
other way to accomplish my goal?

Thanks for any tips, pointers, etc.

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Thu, Apr 04 2013, Alan Hagge wrote:
> I'm trying to put together a test of the write and read speed to some new
> SAN storage.  Our workflow involves writing large numbers of 12 MiB files
> (on the order of 20,000 or so) at a time.  I'd like to set up a config file
> section that will write all 20,000 files then read all 20,000 files and
> report on the write performance and the read performance (separately).
> 
> I've tried something like this:
> 
> [global]
> blocksize=4m
> filesize=12m
> nrfiles=20000
> openfiles=1
> file_service_type=sequential
> create_on_open=1
> ioengine=posixaio
> 
> [write]
> rw=write
> 
> [read]
> stonewall
> rw=read
> 
> But the issue is that the files get created with default filenames
> (write.1.1, write.1.2, etc.), so that when the read job is run, it can't
> find any files (since it expects the files to be named read.1.1, read.1.2,
> etc.).  If I try to specify the "filename=" option in either section, fio no
> longer appends the ".<thread>.<sequence>" to the filename, but rather tries
> to do all I/O to a single file.
> 
> Is there a syntax for the "filename=" option that will allow me to specify a
> different root filename, but still use the ".<thread>.<sequence>" naming
> convention?  Failing that, is there any other way to accomplish my goal?

Good question, and no, you can't currently do that. But you should be
able to do that. Fio has no current option for specifying the naming. We
could have a fileprefix= option that allows you to set that.

So we currently have two options. The first option is that you take on
this task. The file name (if not given with filename=) is generated in
init.c:add_job(), here:

	if (!td->o.filename && !td->files_index && !td->o.read_iolog_file) {
		file_alloced = 1;

		if (td->o.nr_files == 1 && exists_and_not_file(jobname))
			add_file(td, jobname);
		else {
			for (i = 0; i < td->o.nr_files; i++) {
				sprintf(fname, "%s.%d.%d", jobname,
							td->thread_number, i);
				add_file(td, fname);
			}
		}
	}

Options are pretty easy to add, basically just an entry in the
fio_option options[] array in options.c with pretty much
self-explanatory fields. Add matching string type in fio.h to
thread_options{ }.

The other option is that you claim that you are not a programmer, and
then you are at the mercy of someone else (most likely me!) doing it for
you. Since this is a good feature request, I can be talked into that as
well.

Let me know.

-- 
Jens Axboe

Re: How to re-use default sequential filenames?

[Matt Hayward]

Hello Alan,
    I don't have facts to back this up, but here are two things you might try:

1) Can you get away with naming your two jobs ([write] and [read]) the
same thing? E.g. [myjob]?

2) I think filename takes a colon seperated list optionally.  Have you
tried specifying:
filename=file1:file2:file3:...

In each of your jobs?

It seems possible that doing this for 20000 files might create a
problem with the length of the parameter...






On Thu, Apr 4, 2013 at 9:28 AM, Alan Hagge <Alan.Hagge@warnerbros.com> wrote:
> I'm trying to put together a test of the write and read speed to some new
> SAN storage.  Our workflow involves writing large numbers of 12 MiB files
> (on the order of 20,000 or so) at a time.  I'd like to set up a config file
> section that will write all 20,000 files then read all 20,000 files and
> report on the write performance and the read performance (separately).
>
> I've tried something like this:
>
> [global]
> blocksize=4m
> filesize=12m
> nrfiles=20000
> openfiles=1
> file_service_type=sequential
> create_on_open=1
> ioengine=posixaio
>
> [write]
> rw=write
>
> [read]
> stonewall
> rw=read
>
> But the issue is that the files get created with default filenames
> (write.1.1, write.1.2, etc.), so that when the read job is run, it can't
> find any files (since it expects the files to be named read.1.1, read.1.2,
> etc.).  If I try to specify the "filename=" option in either section, fio no
> longer appends the ".<thread>.<sequence>" to the filename, but rather tries
> to do all I/O to a single file.
>
> Is there a syntax for the "filename=" option that will allow me to specify a
> different root filename, but still use the ".<thread>.<sequence>" naming
> convention?  Failing that, is there any other way to accomplish my goal?
>
> Thanks for any tips, pointers, etc.
>
> --
> To unsubscribe from this list: send the line "unsubscribe fio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Matthew Hayward
Director Professional Services
Delphix:
https://www.facebook.com/DelphixCorp
https://twitter.com/delphixcorp
M: 206.849.6389
275 Middlefield Road, Suite 50
Menlo Park, CA 94025
http://www.delphix.com

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Thu, Apr 04 2013, Jens Axboe wrote:
> On Thu, Apr 04 2013, Alan Hagge wrote:
> > I'm trying to put together a test of the write and read speed to some new
> > SAN storage.  Our workflow involves writing large numbers of 12 MiB files
> > (on the order of 20,000 or so) at a time.  I'd like to set up a config file
> > section that will write all 20,000 files then read all 20,000 files and
> > report on the write performance and the read performance (separately).
> > 
> > I've tried something like this:
> > 
> > [global]
> > blocksize=4m
> > filesize=12m
> > nrfiles=20000
> > openfiles=1
> > file_service_type=sequential
> > create_on_open=1
> > ioengine=posixaio
> > 
> > [write]
> > rw=write
> > 
> > [read]
> > stonewall
> > rw=read
> > 
> > But the issue is that the files get created with default filenames
> > (write.1.1, write.1.2, etc.), so that when the read job is run, it can't
> > find any files (since it expects the files to be named read.1.1, read.1.2,
> > etc.).  If I try to specify the "filename=" option in either section, fio no
> > longer appends the ".<thread>.<sequence>" to the filename, but rather tries
> > to do all I/O to a single file.
> > 
> > Is there a syntax for the "filename=" option that will allow me to specify a
> > different root filename, but still use the ".<thread>.<sequence>" naming
> > convention?  Failing that, is there any other way to accomplish my goal?
> 
> Good question, and no, you can't currently do that. But you should be
> able to do that. Fio has no current option for specifying the naming. We
> could have a fileprefix= option that allows you to set that.
> 
> So we currently have two options. The first option is that you take on
> this task. The file name (if not given with filename=) is generated in
> init.c:add_job(), here:
> 
> 	if (!td->o.filename && !td->files_index && !td->o.read_iolog_file) {
> 		file_alloced = 1;
> 
> 		if (td->o.nr_files == 1 && exists_and_not_file(jobname))
> 			add_file(td, jobname);
> 		else {
> 			for (i = 0; i < td->o.nr_files; i++) {
> 				sprintf(fname, "%s.%d.%d", jobname,
> 							td->thread_number, i);
> 				add_file(td, fname);
> 			}
> 		}
> 	}
> 
> Options are pretty easy to add, basically just an entry in the
> fio_option options[] array in options.c with pretty much
> self-explanatory fields. Add matching string type in fio.h to
> thread_options{ }.
> 
> The other option is that you claim that you are not a programmer, and
> then you are at the mercy of someone else (most likely me!) doing it for
> you. Since this is a good feature request, I can be talked into that as
> well.
> 
> Let me know.

OK, so I give it a quick shot, see below. Basically it allows you to set
fileprefix= to override the jobname.threadnumber part of the file. So
not super flexible, we'd need some reserved keywords to make it fully
flexible. Eg it would be nifty if you could do:

fileprefix=$jobnum.$threadnum.$filenum

to get the behaviour we have now, and then you could do:

fileprefix=somename.$filenum

to get the behavior you are looking for.


diff --git a/filesetup.c b/filesetup.c
index e456186..88d6565 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -719,13 +719,14 @@ uint64_t get_start_offset(struct thread_data *td)
 int setup_files(struct thread_data *td)
 {
 	unsigned long long total_size, extend_size;
+	struct thread_options *o = &td->o;
 	struct fio_file *f;
 	unsigned int i;
 	int err = 0, need_extend;
 
 	dprint(FD_FILE, "setup files\n");
 
-	if (td->o.read_iolog_file)
+	if (o->read_iolog_file)
 		goto done;
 
 	/*
@@ -753,15 +754,16 @@ int setup_files(struct thread_data *td)
 			total_size += f->real_file_size;
 	}
 
-	if (td->o.fill_device)
+	if (o->fill_device)
 		td->fill_device_size = get_fs_free_counts(td);
 
 	/*
 	 * device/file sizes are zero and no size given, punt
 	 */
-	if ((!total_size || total_size == -1ULL) && !td->o.size &&
-	    !(td->io_ops->flags & FIO_NOIO) && !td->o.fill_device) {
-		log_err("%s: you need to specify size=\n", td->o.name);
+	if ((!total_size || total_size == -1ULL) && !o->size &&
+	    !(td->io_ops->flags & FIO_NOIO) && !o->fill_device &&
+	    !(o->nr_files && (o->file_size_low || o->file_size_high))) {
+		log_err("%s: you need to specify size=\n", o->name);
 		td_verror(td, EINVAL, "total_file_size");
 		return 1;
 	}
@@ -776,27 +778,26 @@ int setup_files(struct thread_data *td)
 	for_each_file(td, f, i) {
 		f->file_offset = get_start_offset(td);
 
-		if (!td->o.file_size_low) {
+		if (!o->file_size_low) {
 			/*
 			 * no file size range given, file size is equal to
 			 * total size divided by number of files. if that is
 			 * zero, set it to the real file size.
 			 */
-			f->io_size = td->o.size / td->o.nr_files;
+			f->io_size = o->size / o->nr_files;
 			if (!f->io_size)
 				f->io_size = f->real_file_size - f->file_offset;
-		} else if (f->real_file_size < td->o.file_size_low ||
-			   f->real_file_size > td->o.file_size_high) {
-			if (f->file_offset > td->o.file_size_low)
+		} else if (f->real_file_size < o->file_size_low ||
+			   f->real_file_size > o->file_size_high) {
+			if (f->file_offset > o->file_size_low)
 				goto err_offset;
 			/*
 			 * file size given. if it's fixed, use that. if it's a
 			 * range, generate a random size in-between.
 			 */
-			if (td->o.file_size_low == td->o.file_size_high) {
-				f->io_size = td->o.file_size_low
-						- f->file_offset;
-			} else {
+			if (o->file_size_low == o->file_size_high)
+				f->io_size = o->file_size_low - f->file_offset;
+			else {
 				f->io_size = get_rand_file_size(td)
 						- f->file_offset;
 			}
@@ -806,15 +807,15 @@ int setup_files(struct thread_data *td)
 		if (f->io_size == -1ULL)
 			total_size = -1ULL;
 		else {
-                        if (td->o.size_percent)
-                                f->io_size = (f->io_size * td->o.size_percent) / 100;
+                        if (o->size_percent)
+                                f->io_size = (f->io_size * o->size_percent) / 100;
 			total_size += f->io_size;
 		}
 
 		if (f->filetype == FIO_TYPE_FILE &&
 		    (f->io_size + f->file_offset) > f->real_file_size &&
 		    !(td->io_ops->flags & FIO_DISKLESSIO)) {
-			if (!td->o.create_on_open) {
+			if (!o->create_on_open) {
 				need_extend++;
 				extend_size += (f->io_size + f->file_offset);
 			} else
@@ -823,8 +824,8 @@ int setup_files(struct thread_data *td)
 		}
 	}
 
-	if (!td->o.size || td->o.size > total_size)
-		td->o.size = total_size;
+	if (!o->size || o->size > total_size)
+		o->size = total_size;
 
 	/*
 	 * See if we need to extend some files
@@ -833,7 +834,7 @@ int setup_files(struct thread_data *td)
 		temp_stall_ts = 1;
 		if (output_format == FIO_OUTPUT_NORMAL)
 			log_info("%s: Laying out IO file(s) (%u file(s) /"
-				 " %lluMB)\n", td->o.name, need_extend,
+				 " %lluMB)\n", o->name, need_extend,
 					extend_size >> 20);
 
 		for_each_file(td, f, i) {
@@ -844,7 +845,7 @@ int setup_files(struct thread_data *td)
 
 			assert(f->filetype == FIO_TYPE_FILE);
 			fio_file_clear_extend(f);
-			if (!td->o.fill_device) {
+			if (!o->fill_device) {
 				old_len = f->real_file_size;
 				extend_len = f->io_size + f->file_offset -
 						old_len;
@@ -867,23 +868,23 @@ int setup_files(struct thread_data *td)
 	if (err)
 		return err;
 
-	if (!td->o.zone_size)
-		td->o.zone_size = td->o.size;
+	if (!o->zone_size)
+		o->zone_size = o->size;
 
 	/*
 	 * iolog already set the total io size, if we read back
 	 * stored entries.
 	 */
-	if (!td->o.read_iolog_file)
-		td->total_io_size = td->o.size * td->o.loops;
+	if (!o->read_iolog_file)
+		td->total_io_size = o->size * o->loops;
 
 done:
-	if (td->o.create_only)
+	if (o->create_only)
 		td->done = 1;
 
 	return 0;
 err_offset:
-	log_err("%s: you need to specify valid offset=\n", td->o.name);
+	log_err("%s: you need to specify valid offset=\n", o->name);
 	return 1;
 }
 
diff --git a/fio.h b/fio.h
index a1b2a93..16e05c4 100644
--- a/fio.h
+++ b/fio.h
@@ -102,6 +102,7 @@ struct thread_options {
 	char *name;
 	char *directory;
 	char *filename;
+	char *fileprefix;
 	char *opendir;
 	char *ioengine;
 	enum td_ddir td_ddir;
diff --git a/init.c b/init.c
index 9d15318..00701cf 100644
--- a/init.c
+++ b/init.c
@@ -812,6 +812,7 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	unsigned int i;
 	char fname[PATH_MAX];
 	int numjobs, file_alloced;
+	struct thread_options *o = &td->o;
 
 	/*
 	 * the def_thread is just for options, it's not a real job
@@ -835,24 +836,32 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	if (ioengine_load(td))
 		goto err;
 
-	if (td->o.use_thread)
+	if (o->use_thread)
 		nr_thread++;
 	else
 		nr_process++;
 
-	if (td->o.odirect)
+	if (o->odirect)
 		td->io_ops->flags |= FIO_RAWIO;
 
 	file_alloced = 0;
-	if (!td->o.filename && !td->files_index && !td->o.read_iolog_file) {
+	if (!o->filename && !td->files_index && !o->read_iolog_file) {
 		file_alloced = 1;
 
-		if (td->o.nr_files == 1 && exists_and_not_file(jobname))
-			add_file(td, jobname);
-		else {
-			for (i = 0; i < td->o.nr_files; i++) {
-				sprintf(fname, "%s.%d.%d", jobname,
+		if (o->nr_files == 1 && exists_and_not_file(jobname)) {
+			if (o->fileprefix)
+				add_file(td, o->fileprefix);
+			else
+				add_file(td, jobname);
+		} else {
+			for (i = 0; i < o->nr_files; i++) {
+				if (o->fileprefix) {
+					sprintf(fname, "%s.%d", o->fileprefix,
+							i);
+				} else {
+					sprintf(fname, "%s.%d.%d", jobname,
 							td->thread_number, i);
+				}
 				add_file(td, fname);
 			}
 		}
@@ -879,9 +888,9 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 
 	td->mutex = fio_mutex_init(FIO_MUTEX_LOCKED);
 
-	td->ts.clat_percentiles = td->o.clat_percentiles;
-	td->ts.percentile_precision = td->o.percentile_precision;
-	memcpy(td->ts.percentile_list, td->o.percentile_list, sizeof(td->o.percentile_list));
+	td->ts.clat_percentiles = o->clat_percentiles;
+	td->ts.percentile_precision = o->percentile_precision;
+	memcpy(td->ts.percentile_list, o->percentile_list, sizeof(o->percentile_list));
 
 	for (i = 0; i < DDIR_RWDIR_CNT; i++) {
 		td->ts.clat_stat[i].min_val = ULONG_MAX;
@@ -889,9 +898,9 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 		td->ts.lat_stat[i].min_val = ULONG_MAX;
 		td->ts.bw_stat[i].min_val = ULONG_MAX;
 	}
-	td->ddir_seq_nr = td->o.ddir_seq_nr;
+	td->ddir_seq_nr = o->ddir_seq_nr;
 
-	if ((td->o.stonewall || td->o.new_group) && prev_group_jobs) {
+	if ((o->stonewall || o->new_group) && prev_group_jobs) {
 		prev_group_jobs = 0;
 		groupid++;
 	}
@@ -907,43 +916,41 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	if (setup_rate(td))
 		goto err;
 
-	if (td->o.write_lat_log) {
-		setup_log(&td->lat_log, td->o.log_avg_msec);
-		setup_log(&td->slat_log, td->o.log_avg_msec);
-		setup_log(&td->clat_log, td->o.log_avg_msec);
+	if (o->write_lat_log) {
+		setup_log(&td->lat_log, o->log_avg_msec);
+		setup_log(&td->slat_log, o->log_avg_msec);
+		setup_log(&td->clat_log, o->log_avg_msec);
 	}
-	if (td->o.write_bw_log)
-		setup_log(&td->bw_log, td->o.log_avg_msec);
-	if (td->o.write_iops_log)
-		setup_log(&td->iops_log, td->o.log_avg_msec);
+	if (o->write_bw_log)
+		setup_log(&td->bw_log, o->log_avg_msec);
+	if (o->write_iops_log)
+		setup_log(&td->iops_log, o->log_avg_msec);
 
-	if (!td->o.name)
-		td->o.name = strdup(jobname);
+	if (!o->name)
+		o->name = strdup(jobname);
 
 	if (output_format == FIO_OUTPUT_NORMAL) {
 		if (!job_add_num) {
 			if (!strcmp(td->io_ops->name, "cpuio")) {
 				log_info("%s: ioengine=cpu, cpuload=%u,"
-					 " cpucycle=%u\n", td->o.name,
-							td->o.cpuload,
-							td->o.cpucycle);
+					 " cpucycle=%u\n", o->name,
+						o->cpuload, o->cpucycle);
 			} else {
 				char *c1, *c2, *c3, *c4, *c5, *c6;
 
-				c1 = to_kmg(td->o.min_bs[DDIR_READ]);
-				c2 = to_kmg(td->o.max_bs[DDIR_READ]);
-				c3 = to_kmg(td->o.min_bs[DDIR_WRITE]);
-				c4 = to_kmg(td->o.max_bs[DDIR_WRITE]);
-				c5 = to_kmg(td->o.min_bs[DDIR_TRIM]);
-				c6 = to_kmg(td->o.max_bs[DDIR_TRIM]);
+				c1 = to_kmg(o->min_bs[DDIR_READ]);
+				c2 = to_kmg(o->max_bs[DDIR_READ]);
+				c3 = to_kmg(o->min_bs[DDIR_WRITE]);
+				c4 = to_kmg(o->max_bs[DDIR_WRITE]);
+				c5 = to_kmg(o->min_bs[DDIR_TRIM]);
+				c6 = to_kmg(o->max_bs[DDIR_TRIM]);
 
 				log_info("%s: (g=%d): rw=%s, bs=%s-%s/%s-%s/%s-%s,"
 					 " ioengine=%s, iodepth=%u\n",
-						td->o.name, td->groupid,
-						ddir_str[td->o.td_ddir],
+						o->name, td->groupid,
+						ddir_str[o->td_ddir],
 						c1, c2, c3, c4, c5, c6,
-						td->io_ops->name,
-						td->o.iodepth);
+						td->io_ops->name, o->iodepth);
 
 				free(c1);
 				free(c2);
@@ -960,7 +967,7 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	 * recurse add identical jobs, clear numjobs and stonewall options
 	 * as they don't apply to sub-jobs
 	 */
-	numjobs = td->o.numjobs;
+	numjobs = o->numjobs;
 	while (--numjobs) {
 		struct thread_data *td_new = get_new_job(0, td, 1);
 
diff --git a/options.c b/options.c
index 3eb5fdc..e2a0a2e 100644
--- a/options.c
+++ b/options.c
@@ -1132,6 +1132,13 @@ static struct fio_option options[FIO_MAX_OPTS] = {
 		.help	= "File(s) to use for the workload",
 	},
 	{
+		.name	= "fileprefix",
+		.type	= FIO_OPT_STR_STORE,
+		.off1	= td_var_offset(fileprefix),
+		.prio	= -1, /* must come after "directory" */
+		.help	= "Override default <job.threadnum>.filenum naming",
+	},
+	{
 		.name	= "kb_base",
 		.type	= FIO_OPT_INT,
 		.off1	= td_var_offset(kb_base),

-- 
Jens Axboe

RE: How to re-use default sequential filenames?

[Carl Zwanzig]

> From: fio-owner@vger.kernel.org [mailto:fio-owner@vger.kernel.org] On
> Behalf Of Matt Hayward

> It seems possible that doing this for 20000 files might create a
> problem with the length of the parameter...

Seems to me also that multiple servers would be in order. You'd need something pretty beefy to swing that many processes and open files.  Which OS and file system are you using? The original email mentions posixaid, and assuming linux, I've had better throughput with linux's libaio. Also beware of one process forking that many subprocesses. Not saying that it can't be done, but I'd probably distribute that kind of load over at least 10 initiators, and maybe more.

Have you done any back-of-the-envelope calculations for where the bottlenecks might be? A 10g connection at best moves only about 1.2gB/sec (including overhead), which divided by 20k streams gives only about 60kB/sec per stream (have I got that right?) and again, that doesn't account for any overhead.  Likewise, a single 3.5" rotating drive generally won't deliver more than about 150 random write IOPS with write cache enabled, and 2/3 to 1/2 that with the cache disabled. Even with large sequential blocks at the user level, with that many streams into a file system, it can take the appearance of almost pure random access.

z!

Re: How to re-use default sequential filenames?

[Michal Šmucr]

Hello to all,
this is actually great thread. I discovered wonderful fio before two
days during seeking for tool, which allows me to simulate typical
workload with DPX files playback and recording (one file per frame).
I'm playing with it today and slowly getting into options. By
coincidence, i subscribed to this list to ask almost same question as
Alan and found this first thread.. :-)
Reusing of generated frames (file sequences) between write and read
jobs is also important for me and is exactly thing, what i thought
about. I will try to test patch by Jens.

One small thing, sorry for slight derail of thread topic, which come
to my mind was option for kind of automatic set of blocksize during
read to match length of each pre-generated file within sequence, which
fio got from directory using opendir directive. Idea behind this come
from common behaviour of VFX applications, which issue read io for
whole frame size. So application use stat() output to get actual file
size before reading of each frame. If I have same filesize per frame
it is easy to adjust blocksize before benchmark, but if i want to test
read performance of sequence with compressed frames or simulate
mixture of different resolutions, this will be handy.

Thank you and especially Jens for creation of fio (first day with it
is mindblowing :)

Michal Smucr

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Thu, Apr 04 2013, Jens Axboe wrote:
> On Thu, Apr 04 2013, Jens Axboe wrote:
> > On Thu, Apr 04 2013, Alan Hagge wrote:
> > > I'm trying to put together a test of the write and read speed to some new
> > > SAN storage.  Our workflow involves writing large numbers of 12 MiB files
> > > (on the order of 20,000 or so) at a time.  I'd like to set up a config file
> > > section that will write all 20,000 files then read all 20,000 files and
> > > report on the write performance and the read performance (separately).
> > > 
> > > I've tried something like this:
> > > 
> > > [global]
> > > blocksize=4m
> > > filesize=12m
> > > nrfiles=20000
> > > openfiles=1
> > > file_service_type=sequential
> > > create_on_open=1
> > > ioengine=posixaio
> > > 
> > > [write]
> > > rw=write
> > > 
> > > [read]
> > > stonewall
> > > rw=read
> > > 
> > > But the issue is that the files get created with default filenames
> > > (write.1.1, write.1.2, etc.), so that when the read job is run, it can't
> > > find any files (since it expects the files to be named read.1.1, read.1.2,
> > > etc.).  If I try to specify the "filename=" option in either section, fio no
> > > longer appends the ".<thread>.<sequence>" to the filename, but rather tries
> > > to do all I/O to a single file.
> > > 
> > > Is there a syntax for the "filename=" option that will allow me to specify a
> > > different root filename, but still use the ".<thread>.<sequence>" naming
> > > convention?  Failing that, is there any other way to accomplish my goal?
> > 
> > Good question, and no, you can't currently do that. But you should be
> > able to do that. Fio has no current option for specifying the naming. We
> > could have a fileprefix= option that allows you to set that.
> > 
> > So we currently have two options. The first option is that you take on
> > this task. The file name (if not given with filename=) is generated in
> > init.c:add_job(), here:
> > 
> > 	if (!td->o.filename && !td->files_index && !td->o.read_iolog_file) {
> > 		file_alloced = 1;
> > 
> > 		if (td->o.nr_files == 1 && exists_and_not_file(jobname))
> > 			add_file(td, jobname);
> > 		else {
> > 			for (i = 0; i < td->o.nr_files; i++) {
> > 				sprintf(fname, "%s.%d.%d", jobname,
> > 							td->thread_number, i);
> > 				add_file(td, fname);
> > 			}
> > 		}
> > 	}
> > 
> > Options are pretty easy to add, basically just an entry in the
> > fio_option options[] array in options.c with pretty much
> > self-explanatory fields. Add matching string type in fio.h to
> > thread_options{ }.
> > 
> > The other option is that you claim that you are not a programmer, and
> > then you are at the mercy of someone else (most likely me!) doing it for
> > you. Since this is a good feature request, I can be talked into that as
> > well.
> > 
> > Let me know.
> 
> OK, so I give it a quick shot, see below. Basically it allows you to set
> fileprefix= to override the jobname.threadnumber part of the file. So
> not super flexible, we'd need some reserved keywords to make it fully
> flexible. Eg it would be nifty if you could do:
> 
> fileprefix=$jobnum.$threadnum.$filenum

Changed it a bit, the option is now filename_format and it allows the
following keywords, which it replaces with the appropriate name or
number:

$jobname        Name of the job
$jobnum         Number of the job
$filenum        Number of the file in the job

So for your use case, you would do:

filename_format=testfiles.$filenum

and then 'write' and 'read' job would be sharing those files. Let me
know if it works for you.


diff --git a/HOWTO b/HOWTO
index cf6d427..76effee 100644
--- a/HOWTO
+++ b/HOWTO
@@ -285,6 +285,32 @@ filename=str	Fio normally makes up a filename based on the job name,
 		stdin or stdout. Which of the two depends on the read/write
 		direction set.
 
+filename_format=str
+		If sharing multiple files between jobs, it is usually necessary
+		to  have fio generate the exact names that you want. By default,
+		fio will name a file based on the default file format
+		specification of jobname.jobnumber.filenumber. With this
+		option, that can be customized. Fio will recognize and replace
+		the following keywords in this string:
+
+		$jobname
+			The name of the worker thread or process.
+
+		$jobnum
+			The incremental number of the worker thread or
+			process.
+
+		$filenum
+			The incremental number of the file for that worker
+			thread or process.
+
+		To have dependent jobs share a set of files, this option can
+		be set to have fio generate filenames that are shared between
+		the two. For instance, if testfiles.$filenum is specified,
+		file number 4 for any job will be named testfiles.4. The
+		default of $jobname.$jobnum.$filenum will be used if
+		no other format specifier is given.
+
 opendir=str	Tell fio to recursively add any file it can find in this
 		directory and down the file system tree.
 
@@ -405,7 +431,7 @@ filesize=int	Individual file sizes. May be a range, in which case fio
 fill_device=bool
 fill_fs=bool	Sets size to something really large and waits for ENOSPC (no
 		space left on device) as the terminating condition. Only makes
-                sense with sequential write. For a read workload, the mount
+		sense with sequential write. For a read workload, the mount
 		point will be filled first then IO started on the result. This
 		option doesn't make sense if operating on a raw device node,
 		since the size of that is already known by the file system.
diff --git a/filesetup.c b/filesetup.c
index e456186..88d6565 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -719,13 +719,14 @@ uint64_t get_start_offset(struct thread_data *td)
 int setup_files(struct thread_data *td)
 {
 	unsigned long long total_size, extend_size;
+	struct thread_options *o = &td->o;
 	struct fio_file *f;
 	unsigned int i;
 	int err = 0, need_extend;
 
 	dprint(FD_FILE, "setup files\n");
 
-	if (td->o.read_iolog_file)
+	if (o->read_iolog_file)
 		goto done;
 
 	/*
@@ -753,15 +754,16 @@ int setup_files(struct thread_data *td)
 			total_size += f->real_file_size;
 	}
 
-	if (td->o.fill_device)
+	if (o->fill_device)
 		td->fill_device_size = get_fs_free_counts(td);
 
 	/*
 	 * device/file sizes are zero and no size given, punt
 	 */
-	if ((!total_size || total_size == -1ULL) && !td->o.size &&
-	    !(td->io_ops->flags & FIO_NOIO) && !td->o.fill_device) {
-		log_err("%s: you need to specify size=\n", td->o.name);
+	if ((!total_size || total_size == -1ULL) && !o->size &&
+	    !(td->io_ops->flags & FIO_NOIO) && !o->fill_device &&
+	    !(o->nr_files && (o->file_size_low || o->file_size_high))) {
+		log_err("%s: you need to specify size=\n", o->name);
 		td_verror(td, EINVAL, "total_file_size");
 		return 1;
 	}
@@ -776,27 +778,26 @@ int setup_files(struct thread_data *td)
 	for_each_file(td, f, i) {
 		f->file_offset = get_start_offset(td);
 
-		if (!td->o.file_size_low) {
+		if (!o->file_size_low) {
 			/*
 			 * no file size range given, file size is equal to
 			 * total size divided by number of files. if that is
 			 * zero, set it to the real file size.
 			 */
-			f->io_size = td->o.size / td->o.nr_files;
+			f->io_size = o->size / o->nr_files;
 			if (!f->io_size)
 				f->io_size = f->real_file_size - f->file_offset;
-		} else if (f->real_file_size < td->o.file_size_low ||
-			   f->real_file_size > td->o.file_size_high) {
-			if (f->file_offset > td->o.file_size_low)
+		} else if (f->real_file_size < o->file_size_low ||
+			   f->real_file_size > o->file_size_high) {
+			if (f->file_offset > o->file_size_low)
 				goto err_offset;
 			/*
 			 * file size given. if it's fixed, use that. if it's a
 			 * range, generate a random size in-between.
 			 */
-			if (td->o.file_size_low == td->o.file_size_high) {
-				f->io_size = td->o.file_size_low
-						- f->file_offset;
-			} else {
+			if (o->file_size_low == o->file_size_high)
+				f->io_size = o->file_size_low - f->file_offset;
+			else {
 				f->io_size = get_rand_file_size(td)
 						- f->file_offset;
 			}
@@ -806,15 +807,15 @@ int setup_files(struct thread_data *td)
 		if (f->io_size == -1ULL)
 			total_size = -1ULL;
 		else {
-                        if (td->o.size_percent)
-                                f->io_size = (f->io_size * td->o.size_percent) / 100;
+                        if (o->size_percent)
+                                f->io_size = (f->io_size * o->size_percent) / 100;
 			total_size += f->io_size;
 		}
 
 		if (f->filetype == FIO_TYPE_FILE &&
 		    (f->io_size + f->file_offset) > f->real_file_size &&
 		    !(td->io_ops->flags & FIO_DISKLESSIO)) {
-			if (!td->o.create_on_open) {
+			if (!o->create_on_open) {
 				need_extend++;
 				extend_size += (f->io_size + f->file_offset);
 			} else
@@ -823,8 +824,8 @@ int setup_files(struct thread_data *td)
 		}
 	}
 
-	if (!td->o.size || td->o.size > total_size)
-		td->o.size = total_size;
+	if (!o->size || o->size > total_size)
+		o->size = total_size;
 
 	/*
 	 * See if we need to extend some files
@@ -833,7 +834,7 @@ int setup_files(struct thread_data *td)
 		temp_stall_ts = 1;
 		if (output_format == FIO_OUTPUT_NORMAL)
 			log_info("%s: Laying out IO file(s) (%u file(s) /"
-				 " %lluMB)\n", td->o.name, need_extend,
+				 " %lluMB)\n", o->name, need_extend,
 					extend_size >> 20);
 
 		for_each_file(td, f, i) {
@@ -844,7 +845,7 @@ int setup_files(struct thread_data *td)
 
 			assert(f->filetype == FIO_TYPE_FILE);
 			fio_file_clear_extend(f);
-			if (!td->o.fill_device) {
+			if (!o->fill_device) {
 				old_len = f->real_file_size;
 				extend_len = f->io_size + f->file_offset -
 						old_len;
@@ -867,23 +868,23 @@ int setup_files(struct thread_data *td)
 	if (err)
 		return err;
 
-	if (!td->o.zone_size)
-		td->o.zone_size = td->o.size;
+	if (!o->zone_size)
+		o->zone_size = o->size;
 
 	/*
 	 * iolog already set the total io size, if we read back
 	 * stored entries.
 	 */
-	if (!td->o.read_iolog_file)
-		td->total_io_size = td->o.size * td->o.loops;
+	if (!o->read_iolog_file)
+		td->total_io_size = o->size * o->loops;
 
 done:
-	if (td->o.create_only)
+	if (o->create_only)
 		td->done = 1;
 
 	return 0;
 err_offset:
-	log_err("%s: you need to specify valid offset=\n", td->o.name);
+	log_err("%s: you need to specify valid offset=\n", o->name);
 	return 1;
 }
 
diff --git a/fio.1 b/fio.1
index fe8ab76..0c2a243 100644
--- a/fio.1
+++ b/fio.1
@@ -151,6 +151,34 @@ a number of files by separating the names with a `:' character. `\-' is a
 reserved name, meaning stdin or stdout, depending on the read/write direction
 set.
 .TP
+.BI filename_format \fR=\fPstr
+.B If sharing multiple files between jobs, it is usually necessary to have
+fio generate the exact names that you want. By default, fio will name a file
+based on the default file format specification of
+\fBjobname.jobnumber.filenumber\fP. With this option, that can be
+customized. Fio will recognize and replace the following keywords in this
+string:
+.RS
+.RS
+.TP
+.B $jobname
+The name of the worker thread or process.
+.TP
+.B $jobnum
+The incremental number of the worker thread or process.
+.TP
+.B $filenum
+The incremental number of the file for that worker thread or process.
+.RE
+.P
+To have dependent jobs share a set of files, this option can be set to
+have fio generate filenames that are shared between the two. For instance,
+if \fBtestfiles.$filenum\fR is specified, file number 4 for any job will
+be named \fBtestfiles.4\fR. The default of \fB$jobname.$jobnum.$filenum\fR
+will be used if no other format specifier is given.
+.RE
+.P
+.TP
 .BI lockfile \fR=\fPstr
 Fio defaults to not locking any files before it does IO to them. If a file or
 file descriptor is shared, fio can serialize IO to that file to make the end
diff --git a/fio.h b/fio.h
index a1b2a93..db594ab 100644
--- a/fio.h
+++ b/fio.h
@@ -102,6 +102,7 @@ struct thread_options {
 	char *name;
 	char *directory;
 	char *filename;
+	char *filename_format;
 	char *opendir;
 	char *ioengine;
 	enum td_ddir td_ddir;
diff --git a/init.c b/init.c
index 9d15318..0da878d 100644
--- a/init.c
+++ b/init.c
@@ -799,6 +799,82 @@ static int setup_random_seeds(struct thread_data *td)
 	return 0;
 }
 
+enum {
+	FPRE_NONE = 0,
+	FPRE_JOBNAME,
+	FPRE_JOBNUM,
+	FPRE_FILENUM
+};
+
+static struct fpre_keyword {
+	const char *keyword;
+	size_t strlen;
+	int key;
+} fpre_keywords[] = {
+	{ .keyword = "$jobname",	.key = FPRE_JOBNAME, },
+	{ .keyword = "$jobnum",		.key = FPRE_JOBNUM, },
+	{ .keyword = "$filenum",	.key = FPRE_FILENUM, },
+	{ .keyword = NULL, },
+	};
+
+static char *make_filename(char *buf, struct thread_options *o,
+			   const char *jobname, int jobnum, int filenum)
+{
+	struct fpre_keyword *f;
+	char copy[PATH_MAX];
+
+	if (!o->filename_format || !strlen(o->filename_format)) {
+		sprintf(buf, "%s.%d.%d", jobname, jobnum, filenum);
+		return NULL;
+	}
+
+	for (f = &fpre_keywords[0]; f->keyword; f++)
+		f->strlen = strlen(f->keyword);
+
+	strcpy(buf, o->filename_format);
+	memset(copy, 0, sizeof(copy));
+	for (f = &fpre_keywords[0]; f->keyword; f++) {
+		do {
+			size_t pre_len, post_start = 0;
+			char *str, *dst = copy;
+
+			str = strstr(buf, f->keyword);
+			if (!str)
+				break;
+
+			pre_len = str - buf;
+			if (strlen(str) != f->strlen)
+				post_start = pre_len + f->strlen;
+
+			if (pre_len) {
+				strncpy(dst, buf, pre_len);
+				dst += pre_len;
+			}
+
+			switch (f->key) {
+			case FPRE_JOBNAME:
+				dst += sprintf(dst, "%s", jobname);
+				break;
+			case FPRE_JOBNUM:
+				dst += sprintf(dst, "%d", jobnum);
+				break;
+			case FPRE_FILENUM:
+				dst += sprintf(dst, "%d", filenum);
+				break;
+			default:
+				assert(0);
+				break;
+			}
+
+			if (post_start)
+				strcpy(dst, buf + post_start);
+
+			strcpy(buf, copy);
+		} while (1);
+	}
+
+	return buf;
+}
 /*
  * Adds a job to the list of things todo. Sanitizes the various options
  * to make sure we don't have conflicts, and initializes various
@@ -812,6 +888,7 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	unsigned int i;
 	char fname[PATH_MAX];
 	int numjobs, file_alloced;
+	struct thread_options *o = &td->o;
 
 	/*
 	 * the def_thread is just for options, it's not a real job
@@ -835,26 +912,23 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	if (ioengine_load(td))
 		goto err;
 
-	if (td->o.use_thread)
+	if (o->use_thread)
 		nr_thread++;
 	else
 		nr_process++;
 
-	if (td->o.odirect)
+	if (o->odirect)
 		td->io_ops->flags |= FIO_RAWIO;
 
 	file_alloced = 0;
-	if (!td->o.filename && !td->files_index && !td->o.read_iolog_file) {
+	if (!o->filename && !td->files_index && !o->read_iolog_file) {
 		file_alloced = 1;
 
-		if (td->o.nr_files == 1 && exists_and_not_file(jobname))
+		if (o->nr_files == 1 && exists_and_not_file(jobname))
 			add_file(td, jobname);
 		else {
-			for (i = 0; i < td->o.nr_files; i++) {
-				sprintf(fname, "%s.%d.%d", jobname,
-							td->thread_number, i);
-				add_file(td, fname);
-			}
+			for (i = 0; i < o->nr_files; i++)
+				add_file(td, make_filename(fname, o, jobname, td->thread_number, i));
 		}
 	}
 
@@ -879,9 +953,9 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 
 	td->mutex = fio_mutex_init(FIO_MUTEX_LOCKED);
 
-	td->ts.clat_percentiles = td->o.clat_percentiles;
-	td->ts.percentile_precision = td->o.percentile_precision;
-	memcpy(td->ts.percentile_list, td->o.percentile_list, sizeof(td->o.percentile_list));
+	td->ts.clat_percentiles = o->clat_percentiles;
+	td->ts.percentile_precision = o->percentile_precision;
+	memcpy(td->ts.percentile_list, o->percentile_list, sizeof(o->percentile_list));
 
 	for (i = 0; i < DDIR_RWDIR_CNT; i++) {
 		td->ts.clat_stat[i].min_val = ULONG_MAX;
@@ -889,9 +963,9 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 		td->ts.lat_stat[i].min_val = ULONG_MAX;
 		td->ts.bw_stat[i].min_val = ULONG_MAX;
 	}
-	td->ddir_seq_nr = td->o.ddir_seq_nr;
+	td->ddir_seq_nr = o->ddir_seq_nr;
 
-	if ((td->o.stonewall || td->o.new_group) && prev_group_jobs) {
+	if ((o->stonewall || o->new_group) && prev_group_jobs) {
 		prev_group_jobs = 0;
 		groupid++;
 	}
@@ -907,43 +981,41 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	if (setup_rate(td))
 		goto err;
 
-	if (td->o.write_lat_log) {
-		setup_log(&td->lat_log, td->o.log_avg_msec);
-		setup_log(&td->slat_log, td->o.log_avg_msec);
-		setup_log(&td->clat_log, td->o.log_avg_msec);
+	if (o->write_lat_log) {
+		setup_log(&td->lat_log, o->log_avg_msec);
+		setup_log(&td->slat_log, o->log_avg_msec);
+		setup_log(&td->clat_log, o->log_avg_msec);
 	}
-	if (td->o.write_bw_log)
-		setup_log(&td->bw_log, td->o.log_avg_msec);
-	if (td->o.write_iops_log)
-		setup_log(&td->iops_log, td->o.log_avg_msec);
+	if (o->write_bw_log)
+		setup_log(&td->bw_log, o->log_avg_msec);
+	if (o->write_iops_log)
+		setup_log(&td->iops_log, o->log_avg_msec);
 
-	if (!td->o.name)
-		td->o.name = strdup(jobname);
+	if (!o->name)
+		o->name = strdup(jobname);
 
 	if (output_format == FIO_OUTPUT_NORMAL) {
 		if (!job_add_num) {
 			if (!strcmp(td->io_ops->name, "cpuio")) {
 				log_info("%s: ioengine=cpu, cpuload=%u,"
-					 " cpucycle=%u\n", td->o.name,
-							td->o.cpuload,
-							td->o.cpucycle);
+					 " cpucycle=%u\n", o->name,
+						o->cpuload, o->cpucycle);
 			} else {
 				char *c1, *c2, *c3, *c4, *c5, *c6;
 
-				c1 = to_kmg(td->o.min_bs[DDIR_READ]);
-				c2 = to_kmg(td->o.max_bs[DDIR_READ]);
-				c3 = to_kmg(td->o.min_bs[DDIR_WRITE]);
-				c4 = to_kmg(td->o.max_bs[DDIR_WRITE]);
-				c5 = to_kmg(td->o.min_bs[DDIR_TRIM]);
-				c6 = to_kmg(td->o.max_bs[DDIR_TRIM]);
+				c1 = to_kmg(o->min_bs[DDIR_READ]);
+				c2 = to_kmg(o->max_bs[DDIR_READ]);
+				c3 = to_kmg(o->min_bs[DDIR_WRITE]);
+				c4 = to_kmg(o->max_bs[DDIR_WRITE]);
+				c5 = to_kmg(o->min_bs[DDIR_TRIM]);
+				c6 = to_kmg(o->max_bs[DDIR_TRIM]);
 
 				log_info("%s: (g=%d): rw=%s, bs=%s-%s/%s-%s/%s-%s,"
 					 " ioengine=%s, iodepth=%u\n",
-						td->o.name, td->groupid,
-						ddir_str[td->o.td_ddir],
+						o->name, td->groupid,
+						ddir_str[o->td_ddir],
 						c1, c2, c3, c4, c5, c6,
-						td->io_ops->name,
-						td->o.iodepth);
+						td->io_ops->name, o->iodepth);
 
 				free(c1);
 				free(c2);
@@ -960,7 +1032,7 @@ static int add_job(struct thread_data *td, const char *jobname, int job_add_num)
 	 * recurse add identical jobs, clear numjobs and stonewall options
 	 * as they don't apply to sub-jobs
 	 */
-	numjobs = td->o.numjobs;
+	numjobs = o->numjobs;
 	while (--numjobs) {
 		struct thread_data *td_new = get_new_job(0, td, 1);
 
diff --git a/options.c b/options.c
index 3eb5fdc..bca217f 100644
--- a/options.c
+++ b/options.c
@@ -1132,6 +1132,14 @@ static struct fio_option options[FIO_MAX_OPTS] = {
 		.help	= "File(s) to use for the workload",
 	},
 	{
+		.name	= "filename_format",
+		.type	= FIO_OPT_STR_STORE,
+		.off1	= td_var_offset(filename_format),
+		.prio	= -1, /* must come after "directory" */
+		.help	= "Override default $jobname.$jobnum.$filenum naming",
+		.def	= "$jobname.$jobnum.$filenum",
+	},
+	{
 		.name	= "kb_base",
 		.type	= FIO_OPT_INT,
 		.off1	= td_var_offset(kb_base),

-- 
Jens Axboe

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Fri, Apr 05 2013, Michal Šmucr wrote:
> Hello to all,
> this is actually great thread. I discovered wonderful fio before two
> days during seeking for tool, which allows me to simulate typical
> workload with DPX files playback and recording (one file per frame).
> I'm playing with it today and slowly getting into options. By
> coincidence, i subscribed to this list to ask almost same question as
> Alan and found this first thread.. :-)
> Reusing of generated frames (file sequences) between write and read
> jobs is also important for me and is exactly thing, what i thought
> about. I will try to test patch by Jens.
> 
> One small thing, sorry for slight derail of thread topic, which come
> to my mind was option for kind of automatic set of blocksize during
> read to match length of each pre-generated file within sequence, which
> fio got from directory using opendir directive. Idea behind this come
> from common behaviour of VFX applications, which issue read io for
> whole frame size. So application use stat() output to get actual file
> size before reading of each frame. If I have same filesize per frame
> it is easy to adjust blocksize before benchmark, but if i want to test
> read performance of sequence with compressed frames or simulate
> mixture of different resolutions, this will be handy.

It would not be a problem making the block size decision probed or
dynamic. But it's not clear to me from the above what you would base it
on. The file size? Or st_blksize?

> Thank you and especially Jens for creation of fio (first day with it
> is mindblowing :)

You're welcome, glad you like it :-). Fio grows with great suggestions
from people actually using it, which this thread is a good example of.

-- 
Jens Axboe

Re: How to re-use default sequential filenames?

[Michal Šmucr]

2013/4/5 Jens Axboe <axboe@kernel.dk>:
> It would not be a problem making the block size decision probed or
> dynamic. But it's not clear to me from the above what you would base it
> on. The file size? Or st_blksize?

I'm sorry Jens, i wasn't much clear regarding this. I meant file size - st_size.

Michal

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Fri, Apr 05 2013, Michal Šmucr wrote:
> 2013/4/5 Jens Axboe <axboe@kernel.dk>:
> > It would not be a problem making the block size decision probed or
> > dynamic. But it's not clear to me from the above what you would base it
> > on. The file size? Or st_blksize?
> 
> I'm sorry Jens, i wasn't much clear regarding this. I meant file size - st_size.

OK, so how would you size the block size based on the file size? That's
the part that isn't quite clear to me. There could be a number of valid
options in that area, and things like buffered/unbuffered IO might
influence that as well. In other words, it would involve some
heuristics, which I'm never that crazy about adding.

But tell me what you are proposing in detail, and we can take it from
there :-)

-- 
Jens Axboe

Re: How to re-use default sequential filenames?

[Michal Šmucr]

2013/4/5 Jens Axboe <axboe@kernel.dk>:
> and then 'write' and 'read' job would be sharing those files. Let me
> know if it works for you.

Thank you for patch Jens.
Re-using files working for me and i also like that string format
specification. Compiled with last git and tested on Mac OS X and
Centos 5.
I played with fio and sequence tests, it already helps me to get
figures much closer to real world utilization. I always struggled with
generic synthetic benchmarks as it usually don't work with sequences.
So i can roughly set IO sizes, modes, but for example can't simulate
performance differences caused by different file allocation between
one huge file (with few extents due to filesystem internal
optimization) and thousands of files.
Great!

Michal

P.S.: Here is what i tried as single thread HD video job. (and as
example where application read whole frame at once, so bs is
uncommonly equal filesize).

[global]
ioengine=sync
buffered=0
filesize=8305664
bs=8305664
nrfiles=3000
openfiles=1
filename_format=HD_sequence_test.$filenum.dpx
file_service_type=sequential
directory=/mnt/test/io

[2min-sequence-write]
rw=write

[2min-sequence-read]
stonewall
rw=read

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Mon, Apr 08 2013, Michal Šmucr wrote:
> 2013/4/5 Jens Axboe <axboe@kernel.dk>:
> > and then 'write' and 'read' job would be sharing those files. Let me
> > know if it works for you.
> 
> Thank you for patch Jens.
> Re-using files working for me and i also like that string format
> specification. Compiled with last git and tested on Mac OS X and
> Centos 5.
> I played with fio and sequence tests, it already helps me to get
> figures much closer to real world utilization. I always struggled with
> generic synthetic benchmarks as it usually don't work with sequences.
> So i can roughly set IO sizes, modes, but for example can't simulate
> performance differences caused by different file allocation between
> one huge file (with few extents due to filesystem internal
> optimization) and thousands of files.
> Great!

Thanks for testing and confirming that it both works and that the
semantics make sense. I tagged 2.0.15 this morning and kept a few
pending features/fixes in a 'next' branch, all have been pulled into the
master branch. So the filename_format option is now in current -git,
though it did not make 2.0.15 final.

> P.S.: Here is what i tried as single thread HD video job. (and as
> example where application read whole frame at once, so bs is
> uncommonly equal filesize).
> 
> [global]
> ioengine=sync
> buffered=0
> filesize=8305664
> bs=8305664
> nrfiles=3000
> openfiles=1
> filename_format=HD_sequence_test.$filenum.dpx
> file_service_type=sequential
> directory=/mnt/test/io
> 
> [2min-sequence-write]
> rw=write
> 
> [2min-sequence-read]
> stonewall
> rw=read

Looks sane!

-- 
Jens Axboe

Re: How to re-use default sequential filenames?

[Alan Hagge]

On 04/08/2013 04:17 AM, Jens Axboe wrote:
> On Mon, Apr 08 2013, Michal Šmucr wrote:
>> 2013/4/5 Jens Axboe<axboe@kernel.dk>:
>>> and then 'write' and 'read' job would be sharing those files. Let me
>>> know if it works for you.
>> Thank you for patch Jens.
>> Re-using files working for me and i also like that string format
>> specification. Compiled with last git and tested on Mac OS X and
>> Centos 5.
>> I played with fio and sequence tests, it already helps me to get
>> figures much closer to real world utilization. I always struggled with
>> generic synthetic benchmarks as it usually don't work with sequences.
>> So i can roughly set IO sizes, modes, but for example can't simulate
>> performance differences caused by different file allocation between
>> one huge file (with few extents due to filesystem internal
>> optimization) and thousands of files.
>> Great!
> Thanks for testing and confirming that it both works and that the
> semantics make sense. I tagged 2.0.15 this morning and kept a few
> pending features/fixes in a 'next' branch, all have been pulled into the
> master branch. So the filename_format option is now in current -git,
> though it did not make 2.0.15 final.
I too was able to compile the git version and try a test this morning 
and it looks to be working just fine.  This will help us immensely.  
Thanks for the quick response and flexible solution!

Re: How to re-use default sequential filenames?

[Jens Axboe]

On Wed, Apr 10 2013, Alan Hagge wrote:
> On 04/08/2013 04:17 AM, Jens Axboe wrote:
> >On Mon, Apr 08 2013, Michal Šmucr wrote:
> >>2013/4/5 Jens Axboe<axboe@kernel.dk>:
> >>>and then 'write' and 'read' job would be sharing those files. Let me
> >>>know if it works for you.
> >>Thank you for patch Jens.
> >>Re-using files working for me and i also like that string format
> >>specification. Compiled with last git and tested on Mac OS X and
> >>Centos 5.
> >>I played with fio and sequence tests, it already helps me to get
> >>figures much closer to real world utilization. I always struggled with
> >>generic synthetic benchmarks as it usually don't work with sequences.
> >>So i can roughly set IO sizes, modes, but for example can't simulate
> >>performance differences caused by different file allocation between
> >>one huge file (with few extents due to filesystem internal
> >>optimization) and thousands of files.
> >>Great!
> >Thanks for testing and confirming that it both works and that the
> >semantics make sense. I tagged 2.0.15 this morning and kept a few
> >pending features/fixes in a 'next' branch, all have been pulled into the
> >master branch. So the filename_format option is now in current -git,
> >though it did not make 2.0.15 final.
> I too was able to compile the git version and try a test this morning and it
> looks to be working just fine.  This will help us immensely.  Thanks for the
> quick response and flexible solution!

Excellent, glad it works for you, Alan.

-- 
Jens Axboe