From: Mike Snitzer <snitzer@redhat.com>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>,
Eric Sandeen <sandeen@sandeen.net>,
xfs <linux-xfs@vger.kernel.org>, Mark Nelson <mnelson@redhat.com>,
Eric Sandeen <sandeen@redhat.com>
Subject: Re: mkfs.xfs: don't go into multidisk mode if there is only one stripe
Date: Fri, 5 Oct 2018 10:50:02 -0400 [thread overview]
Message-ID: <20181005145001.GA4883@redhat.com> (raw)
In-Reply-To: <CAOi1vP_U-QpABgs+a9oYpYvLWs4D2qVmff=-JEikn7S_=eCAXQ@mail.gmail.com>
On Fri, Oct 05 2018 at 7:27am -0400,
Ilya Dryomov <idryomov@gmail.com> wrote:
> On Fri, Oct 5, 2018 at 12:29 AM Dave Chinner <david@fromorbit.com> wrote:
> >
> > On Thu, Oct 04, 2018 at 01:33:12PM -0500, Eric Sandeen wrote:
> > > On 10/4/18 12:58 PM, Ilya Dryomov wrote:
> > > > rbd devices report the following geometry:
> > > >
> > > > $ blockdev --getss --getpbsz --getiomin --getioopt /dev/rbd0
> > > > 512
> > > > 512
> > > > 4194304
> > > > 4194304
> >
> > dm-thinp does this as well. THis is from the thinp device created
> > by tests/generic/459:
> >
> > 512
> > 4096
> > 65536
> > 65536
>
> (adding Mike)
>
> ... and that 300M filesystem ends up with 8 AGs, when normally you get
> 4 AGs for anything less than 4T. Is that really intended?
>
> AFAIK dm-thinp reports these values for the same exact reason as rbd:
> we are passing up the information about the efficient I/O size. In the
> case of dm-thinp, this is the thinp block size. If you put dm-thinp on
> top of a RAID array, I suspect it would pass up the array's preferred
> sizes, as long as they are a proper factor of the thinp block size.
Right, see pool_io_hints() for all the logic thinp uses to consume block
core's blk_stack_limits() provided limits.. thinp can override if the
underlying limits are _not_ a factor of the thinp's blocksize.
> The high agcount on dm-thinp has come up before and you suggested that
> dm-thinp should report iomin == ioopt (i.e. sunit == swidth). If that
> was the right fix back in 2014, mkfs.xfs must have regressed:
>
> https://marc.info/?l=linux-xfs&m=137783388617206&w=2
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fdfb4c8c1a9fc8dd8cf8eeb4e3ed83573b375285
Yeah, if we're getting larger AG count again, certainly seems like
mkfs.xfs regressed.
Mike
next prev parent reply other threads:[~2018-10-05 21:49 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-04 17:58 [PATCH] mkfs.xfs: don't go into multidisk mode if there is only one stripe Ilya Dryomov
2018-10-04 18:33 ` Eric Sandeen
2018-10-04 18:56 ` Ilya Dryomov
2018-10-04 22:29 ` Dave Chinner
2018-10-05 11:27 ` Ilya Dryomov
2018-10-05 13:51 ` Eric Sandeen
2018-10-05 23:27 ` Dave Chinner
2018-10-06 12:17 ` Ilya Dryomov
2018-10-06 23:20 ` Dave Chinner
2018-10-07 0:14 ` Eric Sandeen
2018-11-29 13:53 ` Ric Wheeler
2018-11-29 21:48 ` Dave Chinner
2018-11-29 23:53 ` Ric Wheeler
2018-11-30 2:25 ` Dave Chinner
2018-11-30 18:00 ` block layer API for file system creation - when to use multidisk mode Ric Wheeler
2018-11-30 18:00 ` Ric Wheeler
2018-11-30 18:05 ` Mark Nelson
2018-11-30 18:05 ` Mark Nelson
2018-12-01 4:35 ` Dave Chinner
2018-12-01 4:35 ` Dave Chinner
2018-12-01 20:52 ` Ric Wheeler
2018-12-01 20:52 ` Ric Wheeler
2018-10-07 13:54 ` [PATCH] mkfs.xfs: don't go into multidisk mode if there is only one stripe Ilya Dryomov
2018-10-10 0:28 ` Dave Chinner
2018-10-05 14:50 ` Mike Snitzer [this message]
2018-10-05 14:55 ` Eric Sandeen
2018-10-05 17:21 ` Ilya Dryomov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20181005145001.GA4883@redhat.com \
--to=snitzer@redhat.com \
--cc=david@fromorbit.com \
--cc=idryomov@gmail.com \
--cc=linux-xfs@vger.kernel.org \
--cc=mnelson@redhat.com \
--cc=sandeen@redhat.com \
--cc=sandeen@sandeen.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.