* /dev/md0 can't be created
[not found] <1215809785.2787621.1427263359309.JavaMail.zimbra@redhat.com>
@ 2015-03-25 6:15 ` Xiao Ni
2015-03-25 6:35 ` NeilBrown
0 siblings, 1 reply; 6+ messages in thread
From: Xiao Ni @ 2015-03-25 6:15 UTC (permalink / raw)
To: linux-raid
Hi all
I have encountered so many times, the raid device is created successfully, but the directory
/dev/md0 can't be created. It can't reproduce 100%.
[root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3] loop2[2] loop1[1] loop0[0]
1788416 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUUUUUU]
bitmap: 0/1 pages [0KB], 65536KB chunk
unused devices: <none>
[root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0
ls: cannot access /dev/md0: No such file or directory
The underline devices are loop devices which are created with big file.
The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm - v3.3.2 - 21st August 2014)
I'll try to reproduce this with upstream kernel and mdadm. But I think it shouldn't be the problem about kernel.
What do you think I should check for this? And which tool is responsible for creating the directory? Maybe
I can add some log to it to find the reason.
Best Regards
Xiao
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: /dev/md0 can't be created
2015-03-25 6:15 ` /dev/md0 can't be created Xiao Ni
@ 2015-03-25 6:35 ` NeilBrown
2015-03-26 7:36 ` Xiao Ni
0 siblings, 1 reply; 6+ messages in thread
From: NeilBrown @ 2015-03-25 6:35 UTC (permalink / raw)
To: Xiao Ni; +Cc: linux-raid
[-- Attachment #1: Type: text/plain, Size: 1415 bytes --]
On Wed, 25 Mar 2015 02:15:34 -0400 (EDT) Xiao Ni <xni@redhat.com> wrote:
> Hi all
>
> I have encountered so many times, the raid device is created successfully, but the directory
> /dev/md0 can't be created. It can't reproduce 100%.
>
> [root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat
> Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
> md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3] loop2[2] loop1[1] loop0[0]
> 1788416 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUUUUUU]
> bitmap: 0/1 pages [0KB], 65536KB chunk
>
> unused devices: <none>
> [root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0
> ls: cannot access /dev/md0: No such file or directory
>
> The underline devices are loop devices which are created with big file.
>
> The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm - v3.3.2 - 21st August 2014)
> I'll try to reproduce this with upstream kernel and mdadm. But I think it shouldn't be the problem about kernel.
>
> What do you think I should check for this? And which tool is responsible for creating the directory? Maybe
> I can add some log to it to find the reason.
>
/dev/md0 is created by udev.
Run
udevadm monitor
to see the events that udev is processing. When and ADD event for "md0" is
processed, /dev/md0 should get created.
NeilBrown
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: /dev/md0 can't be created
2015-03-25 6:35 ` NeilBrown
@ 2015-03-26 7:36 ` Xiao Ni
2015-03-27 6:06 ` Xiao Ni
0 siblings, 1 reply; 6+ messages in thread
From: Xiao Ni @ 2015-03-26 7:36 UTC (permalink / raw)
To: NeilBrown; +Cc: linux-raid
Hi Neil
I can reproduce it now. Do you want me to run udevadm monitor before the test?
And I checked the /var/log/messages, it show the information:
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-2>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-3>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-4>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-5>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-6>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-7>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-9>
Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-8>
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-7 operational as raid disk 5
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-6 operational as raid disk 4
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-5 operational as raid disk 3
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-4 operational as raid disk 2
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-3 operational as raid disk 1
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-2 operational as raid disk 0
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: allocated 0kB
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: raid level 5 active with 6 out of 7 devices, algorithm 2
Oct 20 19:59:59 ibm-z10-25 kernel: md/raid456: discard support disabled due to uncertainty.
Oct 20 19:59:59 ibm-z10-25 kernel: Set raid456.devices_handle_discard_safely=Y to override.
Oct 20 19:59:59 ibm-z10-25 kernel: md0: detected capacity change from 0 to 1881145344
Oct 20 19:59:59 ibm-z10-25 kernel: md: recovery of RAID array md0
Oct 20 19:59:59 ibm-z10-25 kernel: md: minimum _guaranteed_ speed: 1000 KB/sec/disk.
Oct 20 19:59:59 ibm-z10-25 kernel: md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for recovery.
Oct 20 19:59:59 ibm-z10-25 kernel: md: using 128k window, over a total of 306176k.
Oct 20 19:59:59 ibm-z10-25 systemd-udevd: inotify_add_watch(7, /dev/md0, 10) failed: No such file or directory
Xiao
----- Original Message -----
> From: "NeilBrown" <neilb@suse.de>
> To: "Xiao Ni" <xni@redhat.com>
> Cc: linux-raid@vger.kernel.org
> Sent: Wednesday, March 25, 2015 2:35:29 PM
> Subject: Re: /dev/md0 can't be created
>
> On Wed, 25 Mar 2015 02:15:34 -0400 (EDT) Xiao Ni <xni@redhat.com> wrote:
>
> > Hi all
> >
> > I have encountered so many times, the raid device is created
> > successfully, but the directory
> > /dev/md0 can't be created. It can't reproduce 100%.
> >
> > [root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat
> > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
> > md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3]
> > loop2[2] loop1[1] loop0[0]
> > 1788416 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUUUUUU]
> > bitmap: 0/1 pages [0KB], 65536KB chunk
> >
> > unused devices: <none>
> > [root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0
> > ls: cannot access /dev/md0: No such file or directory
> >
> > The underline devices are loop devices which are created with big file.
> >
> > The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm - v3.3.2
> > - 21st August 2014)
> > I'll try to reproduce this with upstream kernel and mdadm. But I think it
> > shouldn't be the problem about kernel.
> >
> > What do you think I should check for this? And which tool is
> > responsible for creating the directory? Maybe
> > I can add some log to it to find the reason.
> >
>
> /dev/md0 is created by udev.
> Run
> udevadm monitor
>
> to see the events that udev is processing. When and ADD event for "md0" is
> processed, /dev/md0 should get created.
>
> NeilBrown
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: /dev/md0 can't be created
2015-03-26 7:36 ` Xiao Ni
@ 2015-03-27 6:06 ` Xiao Ni
2015-04-01 2:53 ` NeilBrown
0 siblings, 1 reply; 6+ messages in thread
From: Xiao Ni @ 2015-03-27 6:06 UTC (permalink / raw)
To: NeilBrown; +Cc: linux-raid
[-- Attachment #1: Type: text/plain, Size: 4527 bytes --]
I'm lucky, I reproduced it again and I ran the command udevadm monitor > monitor before test.
I'll put it in as an attachment.
I found there is a not whole message in the last line.
Xiao
----- Original Message -----
> From: "Xiao Ni" <xni@redhat.com>
> To: "NeilBrown" <neilb@suse.de>
> Cc: linux-raid@vger.kernel.org
> Sent: Thursday, March 26, 2015 3:36:35 PM
> Subject: Re: /dev/md0 can't be created
>
> Hi Neil
>
> I can reproduce it now. Do you want me to run udevadm monitor before the
> test?
> And I checked the /var/log/messages, it show the information:
>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-2>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-3>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-4>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-5>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-6>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-7>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-9>
> Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-8>
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-7 operational as
> raid disk 5
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-6 operational as
> raid disk 4
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-5 operational as
> raid disk 3
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-4 operational as
> raid disk 2
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-3 operational as
> raid disk 1
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-2 operational as
> raid disk 0
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: allocated 0kB
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: raid level 5 active with 6
> out of 7 devices, algorithm 2
> Oct 20 19:59:59 ibm-z10-25 kernel: md/raid456: discard support disabled due
> to uncertainty.
> Oct 20 19:59:59 ibm-z10-25 kernel: Set
> raid456.devices_handle_discard_safely=Y to override.
> Oct 20 19:59:59 ibm-z10-25 kernel: md0: detected capacity change from 0 to
> 1881145344
> Oct 20 19:59:59 ibm-z10-25 kernel: md: recovery of RAID array md0
> Oct 20 19:59:59 ibm-z10-25 kernel: md: minimum _guaranteed_ speed: 1000
> KB/sec/disk.
> Oct 20 19:59:59 ibm-z10-25 kernel: md: using maximum available idle IO
> bandwidth (but not more than 200000 KB/sec) for recovery.
> Oct 20 19:59:59 ibm-z10-25 kernel: md: using 128k window, over a total of
> 306176k.
> Oct 20 19:59:59 ibm-z10-25 systemd-udevd: inotify_add_watch(7, /dev/md0, 10)
> failed: No such file or directory
>
> Xiao
>
> ----- Original Message -----
> > From: "NeilBrown" <neilb@suse.de>
> > To: "Xiao Ni" <xni@redhat.com>
> > Cc: linux-raid@vger.kernel.org
> > Sent: Wednesday, March 25, 2015 2:35:29 PM
> > Subject: Re: /dev/md0 can't be created
> >
> > On Wed, 25 Mar 2015 02:15:34 -0400 (EDT) Xiao Ni <xni@redhat.com> wrote:
> >
> > > Hi all
> > >
> > > I have encountered so many times, the raid device is created
> > > successfully, but the directory
> > > /dev/md0 can't be created. It can't reproduce 100%.
> > >
> > > [root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat
> > > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
> > > md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3]
> > > loop2[2] loop1[1] loop0[0]
> > > 1788416 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUUUUUU]
> > > bitmap: 0/1 pages [0KB], 65536KB chunk
> > >
> > > unused devices: <none>
> > > [root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0
> > > ls: cannot access /dev/md0: No such file or directory
> > >
> > > The underline devices are loop devices which are created with big
> > > file.
> > >
> > > The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm -
> > > v3.3.2
> > > - 21st August 2014)
> > > I'll try to reproduce this with upstream kernel and mdadm. But I think it
> > > shouldn't be the problem about kernel.
> > >
> > > What do you think I should check for this? And which tool is
> > > responsible for creating the directory? Maybe
> > > I can add some log to it to find the reason.
> > >
> >
> > /dev/md0 is created by udev.
> > Run
> > udevadm monitor
> >
> > to see the events that udev is processing. When and ADD event for "md0" is
> > processed, /dev/md0 should get created.
> >
> > NeilBrown
> >
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
[-- Attachment #2: monitor --]
[-- Type: application/octet-stream, Size: 24576 bytes --]
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent
KERNEL[6515.301274] change /devices/virtual/block/loop0 (block)
KERNEL[6515.303462] change /devices/virtual/block/loop0 (block)
UDEV [6515.319066] change /devices/virtual/block/loop0 (block)
UDEV [6515.331930] change /devices/virtual/block/loop0 (block)
KERNEL[6517.641752] change /devices/virtual/block/loop1 (block)
KERNEL[6517.642637] change /devices/virtual/block/loop1 (block)
UDEV [6517.660489] change /devices/virtual/block/loop1 (block)
UDEV [6517.677432] change /devices/virtual/block/loop1 (block)
KERNEL[6520.022457] change /devices/virtual/block/loop2 (block)
KERNEL[6520.023667] change /devices/virtual/block/loop2 (block)
UDEV [6520.039374] change /devices/virtual/block/loop2 (block)
UDEV [6520.058352] change /devices/virtual/block/loop2 (block)
KERNEL[6522.368026] change /devices/virtual/block/loop3 (block)
KERNEL[6522.368622] change /devices/virtual/block/loop3 (block)
UDEV [6522.383221] change /devices/virtual/block/loop3 (block)
UDEV [6522.402220] change /devices/virtual/block/loop3 (block)
KERNEL[6525.645736] change /devices/virtual/block/loop4 (block)
KERNEL[6525.647442] change /devices/virtual/block/loop4 (block)
UDEV [6525.663895] change /devices/virtual/block/loop4 (block)
UDEV [6525.679432] change /devices/virtual/block/loop4 (block)
KERNEL[6529.974901] change /devices/virtual/block/loop5 (block)
KERNEL[6529.976536] change /devices/virtual/block/loop5 (block)
UDEV [6529.993692] change /devices/virtual/block/loop5 (block)
UDEV [6530.009535] change /devices/virtual/block/loop5 (block)
KERNEL[6535.055372] change /devices/virtual/block/loop6 (block)
KERNEL[6535.057058] change /devices/virtual/block/loop6 (block)
UDEV [6535.072879] change /devices/virtual/block/loop6 (block)
UDEV [6535.087172] change /devices/virtual/block/loop6 (block)
KERNEL[6540.574575] change /devices/virtual/block/loop7 (block)
KERNEL[6540.576235] change /devices/virtual/block/loop7 (block)
UDEV [6540.593438] change /devices/virtual/block/loop7 (block)
UDEV [6540.607785] change /devices/virtual/block/loop7 (block)
KERNEL[6540.754883] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6540.755896] add /devices/virtual/block/md0 (block)
UDEV [6540.755917] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6540.757982] change /devices/virtual/block/loop0 (block)
UDEV [6540.769174] change /devices/virtual/block/loop0 (block)
UDEV [6540.770964] add /devices/virtual/block/md0 (block)
KERNEL[6541.267525] change /devices/virtual/block/loop0 (block)
KERNEL[6541.268027] change /devices/virtual/block/loop1 (block)
UDEV [6541.280223] change /devices/virtual/block/loop1 (block)
UDEV [6541.280839] change /devices/virtual/block/loop0 (block)
KERNEL[6541.750291] change /devices/virtual/block/loop1 (block)
KERNEL[6541.751248] change /devices/virtual/block/loop2 (block)
UDEV [6541.763540] change /devices/virtual/block/loop1 (block)
UDEV [6541.763573] change /devices/virtual/block/loop2 (block)
KERNEL[6543.691132] change /devices/virtual/block/loop2 (block)
KERNEL[6543.691992] change /devices/virtual/block/loop3 (block)
UDEV [6543.703832] change /devices/virtual/block/loop3 (block)
UDEV [6543.705042] change /devices/virtual/block/loop2 (block)
KERNEL[6547.431384] change /devices/virtual/block/loop3 (block)
KERNEL[6547.433030] change /devices/virtual/block/loop4 (block)
UDEV [6547.447432] change /devices/virtual/block/loop3 (block)
UDEV [6547.447464] change /devices/virtual/block/loop4 (block)
KERNEL[6552.923835] change /devices/virtual/block/loop4 (block)
KERNEL[6552.925517] change /devices/virtual/block/loop5 (block)
UDEV [6552.939977] change /devices/virtual/block/loop5 (block)
UDEV [6552.943144] change /devices/virtual/block/loop4 (block)
KERNEL[6557.602230] change /devices/virtual/block/loop5 (block)
KERNEL[6557.604138] change /devices/virtual/block/loop6 (block)
UDEV [6557.618449] change /devices/virtual/block/loop6 (block)
UDEV [6557.619513] change /devices/virtual/block/loop5 (block)
KERNEL[6561.675460] change /devices/virtual/block/loop6 (block)
UDEV [6561.689512] change /devices/virtual/block/loop6 (block)
KERNEL[6561.743692] change /devices/virtual/block/md0 (block)
UDEV [6561.784740] change /devices/virtual/block/md0 (block)
KERNEL[6605.925900] change /devices/virtual/block/md0 (block)
UDEV [6606.093197] change /devices/virtual/block/md0 (block)
KERNEL[6609.034238] change /devices/virtual/block/md0 (block)
UDEV [6609.683910] change /devices/virtual/block/md0 (block)
KERNEL[6609.806307] change /devices/virtual/block/md0 (block)
UDEV [6609.943069] change /devices/virtual/block/md0 (block)
KERNEL[6610.665984] change /devices/virtual/block/md0 (block)
UDEV [6611.279813] change /devices/virtual/block/md0 (block)
KERNEL[6611.567864] change /devices/virtual/block/md0 (block)
UDEV [6611.770054] change /devices/virtual/block/md0 (block)
KERNEL[6612.124655] change /devices/virtual/block/md0 (block)
UDEV [6612.182382] change /devices/virtual/block/md0 (block)
KERNEL[6612.532394] change /devices/virtual/block/md0 (block)
UDEV [6613.142899] change /devices/virtual/block/md0 (block)
KERNEL[6613.450778] change /devices/virtual/block/md0 (block)
UDEV [6613.941184] change /devices/virtual/block/md0 (block)
KERNEL[6613.989039] change /devices/virtual/block/md0 (block)
UDEV [6614.025015] change /devices/virtual/block/md0 (block)
KERNEL[6614.056150] change /devices/virtual/block/md0 (block)
UDEV [6614.099238] change /devices/virtual/block/md0 (block)
KERNEL[6614.776258] change /devices/virtual/block/md0 (block)
UDEV [6614.922649] change /devices/virtual/block/md0 (block)
KERNEL[6614.962054] change /devices/virtual/block/md0 (block)
UDEV [6615.000911] change /devices/virtual/block/md0 (block)
KERNEL[6615.169124] change /devices/virtual/block/md0 (block)
UDEV [6615.355895] change /devices/virtual/block/md0 (block)
KERNEL[6660.683679] change /devices/virtual/block/md0 (block)
UDEV [6660.757371] change /devices/virtual/block/md0 (block)
KERNEL[6660.771043] change /devices/virtual/block/md0 (block)
UDEV [6660.814874] change /devices/virtual/block/md0 (block)
KERNEL[6671.628859] change /devices/virtual/block/md0 (block)
UDEV [6671.830377] change /devices/virtual/block/md0 (block)
KERNEL[6687.755208] change /devices/virtual/block/md0 (block)
KERNEL[6687.885216] change /devices/virtual/block/md0 (block)
KERNEL[6687.885488] change /devices/virtual/block/md0 (block)
KERNEL[6687.886975] remove /devices/virtual/bdi/9:0 (bdi)
UDEV [6687.888247] change /devices/virtual/block/md0 (block)
KERNEL[6687.888276] remove /devices/virtual/block/md0 (block)
UDEV [6687.889881] remove /devices/virtual/bdi/9:0 (bdi)
UDEV [6687.903134] change /devices/virtual/block/md0 (block)
UDEV [6687.915560] change /devices/virtual/block/md0 (block)
KERNEL[6687.919211] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6687.919838] add /devices/virtual/block/md0 (block)
UDEV [6687.920574] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6687.926955] change /devices/virtual/block/md0 (block)
UDEV [6687.926978] remove /devices/virtual/block/md0 (block)
KERNEL[6687.927010] change /devices/virtual/block/loop0 (block)
KERNEL[6687.927025] change /devices/virtual/block/loop1 (block)
KERNEL[6687.928120] change /devices/virtual/block/loop2 (block)
KERNEL[6687.928795] change /devices/virtual/block/loop3 (block)
KERNEL[6687.936185] change /devices/virtual/block/loop4 (block)
KERNEL[6687.936216] change /devices/virtual/block/loop5 (block)
KERNEL[6687.936243] change /devices/virtual/block/loop6 (block)
KERNEL[6687.936271] change /devices/virtual/block/loop2 (block)
UDEV [6687.937469] change /devices/virtual/block/loop0 (block)
KERNEL[6687.941864] change /devices/virtual/block/loop4 (block)
KERNEL[6687.943995] change /devices/virtual/block/loop5 (block)
UDEV [6687.953942] change /devices/virtual/block/loop6 (block)
UDEV [6687.958603] change /devices/virtual/block/loop1 (block)
KERNEL[6687.963136] change /devices/virtual/block/loop0 (block)
UDEV [6687.963160] change /devices/virtual/block/loop4 (block)
UDEV [6687.969767] change /devices/virtual/block/loop5 (block)
UDEV [6687.973885] change /devices/virtual/block/loop0 (block)
UDEV [6687.976070] change /devices/virtual/block/loop2 (block)
UDEV [6687.981657] change /devices/virtual/block/loop3 (block)
UDEV [6687.982961] change /devices/virtual/block/loop4 (block)
UDEV [6687.994403] change /devices/virtual/block/loop5 (block)
UDEV [6687.994436] change /devices/virtual/block/loop2 (block)
KERNEL[6688.012417] change /devices/virtual/block/md0 (block)
UDEV [6688.039546] add /devices/virtual/block/md0 (block)
UDEV [6688.074203] change /devices/virtual/block/md0 (block)
UDEV [6688.102564] change /devices/virtual/block/md0 (block)
KERNEL[6734.583172] change /devices/virtual/block/md0 (block)
UDEV [6735.326056] change /devices/virtual/block/md0 (block)
KERNEL[6735.342604] change /devices/virtual/block/md0 (block)
UDEV [6735.441686] change /devices/virtual/block/md0 (block)
KERNEL[6737.082876] change /devices/virtual/block/md0 (block)
UDEV [6737.679813] change /devices/virtual/block/md0 (block)
KERNEL[6738.181769] change /devices/virtual/block/md0 (block)
UDEV [6738.533050] change /devices/virtual/block/md0 (block)
KERNEL[6738.991194] change /devices/virtual/block/md0 (block)
UDEV [6739.179237] change /devices/virtual/block/md0 (block)
KERNEL[6739.299921] change /devices/virtual/block/md0 (block)
UDEV [6739.464539] change /devices/virtual/block/md0 (block)
KERNEL[6739.512987] change /devices/virtual/block/md0 (block)
UDEV [6739.685571] change /devices/virtual/block/md0 (block)
KERNEL[6739.767087] change /devices/virtual/block/md0 (block)
UDEV [6740.199527] change /devices/virtual/block/md0 (block)
KERNEL[6740.223356] change /devices/virtual/block/md0 (block)
UDEV [6740.348953] change /devices/virtual/block/md0 (block)
KERNEL[6740.722135] change /devices/virtual/block/md0 (block)
UDEV [6740.917654] change /devices/virtual/block/md0 (block)
KERNEL[6740.995449] change /devices/virtual/block/md0 (block)
UDEV [6741.027057] change /devices/virtual/block/md0 (block)
KERNEL[6741.176307] change /devices/virtual/block/md0 (block)
UDEV [6741.287848] change /devices/virtual/block/md0 (block)
KERNEL[6788.019597] change /devices/virtual/block/md0 (block)
UDEV [6788.054290] change /devices/virtual/block/md0 (block)
KERNEL[6788.075712] change /devices/virtual/block/md0 (block)
UDEV [6788.105865] change /devices/virtual/block/md0 (block)
KERNEL[6788.114089] change /devices/virtual/block/md0 (block)
KERNEL[6788.237174] change /devices/virtual/block/md0 (block)
KERNEL[6788.237429] change /devices/virtual/block/md0 (block)
KERNEL[6788.238775] remove /devices/virtual/bdi/9:0 (bdi)
UDEV [6788.239246] change /devices/virtual/block/md0 (block)
KERNEL[6788.240270] remove /devices/virtual/block/md0 (block)
UDEV [6788.241486] remove /devices/virtual/bdi/9:0 (bdi)
UDEV [6788.253115] change /devices/virtual/block/md0 (block)
UDEV [6788.263858] change /devices/virtual/block/md0 (block)
KERNEL[6788.267274] change /devices/virtual/block/loop0 (block)
UDEV [6788.271644] remove /devices/virtual/block/md0 (block)
UDEV [6788.282811] change /devices/virtual/block/loop0 (block)
KERNEL[6788.292175] change /devices/virtual/block/loop1 (block)
UDEV [6788.307988] change /devices/virtual/block/loop1 (block)
KERNEL[6788.325582] change /devices/virtual/block/loop2 (block)
UDEV [6788.340242] change /devices/virtual/block/loop2 (block)
KERNEL[6788.350532] change /devices/virtual/block/loop3 (block)
UDEV [6788.365899] change /devices/virtual/block/loop3 (block)
KERNEL[6788.375606] change /devices/virtual/block/loop4 (block)
UDEV [6788.389328] change /devices/virtual/block/loop4 (block)
KERNEL[6788.400577] change /devices/virtual/block/loop5 (block)
UDEV [6788.414682] change /devices/virtual/block/loop5 (block)
KERNEL[6788.425803] change /devices/virtual/block/loop6 (block)
UDEV [6788.440313] change /devices/virtual/block/loop6 (block)
KERNEL[6788.510976] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6788.511568] add /devices/virtual/block/md0 (block)
UDEV [6788.512115] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6788.513826] change /devices/virtual/block/loop0 (block)
UDEV [6788.525079] add /devices/virtual/block/md0 (block)
UDEV [6788.525435] change /devices/virtual/block/loop0 (block)
KERNEL[6788.558815] change /devices/virtual/block/loop0 (block)
KERNEL[6788.559677] change /devices/virtual/block/loop1 (block)
UDEV [6788.569728] change /devices/virtual/block/loop0 (block)
UDEV [6788.570191] change /devices/virtual/block/loop1 (block)
KERNEL[6788.600595] change /devices/virtual/block/loop1 (block)
KERNEL[6788.601480] change /devices/virtual/block/loop2 (block)
UDEV [6788.612566] change /devices/virtual/block/loop1 (block)
UDEV [6788.612629] change /devices/virtual/block/loop2 (block)
KERNEL[6788.650466] change /devices/virtual/block/loop2 (block)
KERNEL[6788.651371] change /devices/virtual/block/loop3 (block)
UDEV [6788.661917] change /devices/virtual/block/loop2 (block)
UDEV [6788.662598] change /devices/virtual/block/loop3 (block)
KERNEL[6788.700620] change /devices/virtual/block/loop3 (block)
KERNEL[6788.701543] change /devices/virtual/block/loop4 (block)
UDEV [6788.712727] change /devices/virtual/block/loop3 (block)
UDEV [6788.713231] change /devices/virtual/block/loop4 (block)
KERNEL[6788.750621] change /devices/virtual/block/loop4 (block)
KERNEL[6788.751586] change /devices/virtual/block/loop5 (block)
UDEV [6788.763155] change /devices/virtual/block/loop5 (block)
UDEV [6788.763308] change /devices/virtual/block/loop4 (block)
KERNEL[6788.800558] change /devices/virtual/block/loop5 (block)
KERNEL[6788.801416] change /devices/virtual/block/loop6 (block)
UDEV [6788.812158] change /devices/virtual/block/loop5 (block)
UDEV [6788.812471] change /devices/virtual/block/loop6 (block)
KERNEL[6788.842301] change /devices/virtual/block/loop6 (block)
KERNEL[6788.843113] change /devices/virtual/block/loop7 (block)
UDEV [6788.853459] change /devices/virtual/block/loop6 (block)
UDEV [6788.854106] change /devices/virtual/block/loop7 (block)
KERNEL[6788.883836] change /devices/virtual/block/loop7 (block)
UDEV [6788.894871] change /devices/virtual/block/loop7 (block)
KERNEL[6789.011564] change /devices/virtual/block/md0 (block)
UDEV [6789.065268] change /devices/virtual/block/md0 (block)
KERNEL[6884.248066] change /devices/virtual/block/md0 (block)
UDEV [6885.360337] change /devices/virtual/block/md0 (block)
KERNEL[6885.695050] change /devices/virtual/block/md0 (block)
UDEV [6888.854765] change /devices/virtual/block/md0 (block)
KERNEL[6889.225064] change /devices/virtual/block/md0 (block)
UDEV [6889.929240] change /devices/virtual/block/md0 (block)
KERNEL[6890.840079] change /devices/virtual/block/md0 (block)
UDEV [6891.820037] change /devices/virtual/block/md0 (block)
KERNEL[6893.293889] change /devices/virtual/block/md0 (block)
KERNEL[6893.302149] change /devices/virtual/block/md0 (block)
KERNEL[6893.302171] change /devices/virtual/block/md0 (block)
UDEV [6894.249836] change /devices/virtual/block/md0 (block)
UDEV [6894.283789] change /devices/virtual/block/md0 (block)
UDEV [6894.317230] change /devices/virtual/block/md0 (block)
KERNEL[6894.368336] change /devices/virtual/block/md0 (block)
UDEV [6896.026075] change /devices/virtual/block/md0 (block)
KERNEL[6896.045684] change /devices/virtual/block/md0 (block)
UDEV [6896.684701] change /devices/virtual/block/md0 (block)
KERNEL[6896.745566] change /devices/virtual/block/md0 (block)
UDEV [6896.998419] change /devices/virtual/block/md0 (block)
KERNEL[6926.410642] change /devices/virtual/block/md0 (block)
UDEV [6926.449836] change /devices/virtual/block/md0 (block)
KERNEL[6926.538568] change /devices/virtual/block/md0 (block)
KERNEL[6926.539464] change /devices/virtual/block/md0 (block)
KERNEL[6926.539641] change /devices/virtual/block/md0 (block)
UDEV [6926.577725] change /devices/virtual/block/md0 (block)
UDEV [6931.596644] change /devices/virtual/block/md0 (block)
UDEV [6931.628094] change /devices/virtual/block/md0 (block)
KERNEL[6933.881018] change /devices/virtual/block/md0 (block)
UDEV [6933.922429] change /devices/virtual/block/md0 (block)
KERNEL[6962.269802] change /devices/virtual/block/md0 (block)
KERNEL[6977.715345] change /devices/virtual/block/md0 (block)
KERNEL[6977.716614] change /devices/virtual/block/md0 (block)
UDEV [6977.717886] change /devices/virtual/block/md0 (block)
KERNEL[6977.719960] remove /devices/virtual/bdi/9:0 (bdi)
KERNEL[6977.722557] remove /devices/virtual/block/md0 (block)
UDEV [6977.723251] remove /devices/virtual/bdi/9:0 (bdi)
UDEV [6977.727476] change /devices/virtual/block/md0 (block)
UDEV [6977.737814] change /devices/virtual/block/md0 (block)
UDEV [6977.744947] remove /devices/virtual/block/md0 (block)
KERNEL[6977.751407] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6977.752291] add /devices/virtual/block/md0 (block)
UDEV [6977.752687] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[6977.755950] change /devices/virtual/block/md0 (block)
KERNEL[6977.756472] change /devices/virtual/block/loop0 (block)
KERNEL[6977.763863] change /devices/virtual/block/loop1 (block)
KERNEL[6977.764093] change /devices/virtual/block/loop2 (block)
UDEV [6977.766600] add /devices/virtual/block/md0 (block)
KERNEL[6977.766981] change /devices/virtual/block/loop3 (block)
KERNEL[6977.775461] change /devices/virtual/block/loop4 (block)
KERNEL[6977.775484] change /devices/virtual/block/loop5 (block)
KERNEL[6977.775503] change /devices/virtual/block/loop6 (block)
KERNEL[6977.775522] change /devices/virtual/block/loop7 (block)
UDEV [6977.781891] change /devices/virtual/block/loop0 (block)
UDEV [6977.797031] change /devices/virtual/block/loop1 (block)
UDEV [6977.798102] change /devices/virtual/block/loop3 (block)
UDEV [6977.800268] change /devices/virtual/block/loop2 (block)
UDEV [6977.802618] change /devices/virtual/block/loop7 (block)
UDEV [6977.807059] change /devices/virtual/block/loop5 (block)
UDEV [6977.807082] change /devices/virtual/block/md0 (block)
KERNEL[6977.818065] change /devices/virtual/block/loop7 (block)
UDEV [6977.820035] change /devices/virtual/block/loop6 (block)
KERNEL[6977.822047] change /devices/virtual/block/loop0 (block)
UDEV [6977.822965] change /devices/virtual/block/loop4 (block)
UDEV [6977.834246] change /devices/virtual/block/loop7 (block)
UDEV [6977.835720] change /devices/virtual/block/loop0 (block)
KERNEL[6977.939436] change /devices/virtual/block/md0 (block)
UDEV [6977.981041] change /devices/virtual/block/md0 (block)
KERNEL[7026.071351] change /devices/virtual/block/md0 (block)
UDEV [7026.984276] change /devices/virtual/block/md0 (block)
KERNEL[7027.751297] change /devices/virtual/block/md0 (block)
UDEV [7029.623042] change /devices/virtual/block/md0 (block)
KERNEL[7030.138935] change /devices/virtual/block/md0 (block)
UDEV [7031.286231] change /devices/virtual/block/md0 (block)
KERNEL[7031.429465] change /devices/virtual/block/md0 (block)
UDEV [7031.619533] change /devices/virtual/block/md0 (block)
KERNEL[7033.103921] change /devices/virtual/block/md0 (block)
UDEV [7034.158973] change /devices/virtual/block/md0 (block)
KERNEL[7034.955973] change /devices/virtual/block/md0 (block)
UDEV [7035.549463] change /devices/virtual/block/md0 (block)
KERNEL[7035.745108] change /devices/virtual/block/md0 (block)
UDEV [7036.201920] change /devices/virtual/block/md0 (block)
KERNEL[7036.816814] change /devices/virtual/block/md0 (block)
UDEV [7038.079945] change /devices/virtual/block/md0 (block)
KERNEL[7038.837269] change /devices/virtual/block/md0 (block)
UDEV [7040.239793] change /devices/virtual/block/md0 (block)
KERNEL[7040.334491] change /devices/virtual/block/md0 (block)
UDEV [7040.365864] change /devices/virtual/block/md0 (block)
KERNEL[7040.367420] change /devices/virtual/block/md0 (block)
UDEV [7040.422668] change /devices/virtual/block/md0 (block)
KERNEL[7041.462403] change /devices/virtual/block/md0 (block)
UDEV [7042.279653] change /devices/virtual/block/md0 (block)
KERNEL[7042.901076] change /devices/virtual/block/md0 (block)
UDEV [7042.972826] change /devices/virtual/block/md0 (block)
KERNEL[7082.239840] change /devices/virtual/block/md0 (block)
UDEV [7082.610794] change /devices/virtual/block/md0 (block)
KERNEL[7082.995887] change /devices/virtual/block/md0 (block)
KERNEL[7083.471178] change /devices/virtual/block/md0 (block)
KERNEL[7083.471420] change /devices/virtual/block/md0 (block)
KERNEL[7083.472801] remove /devices/virtual/bdi/9:0 (bdi)
KERNEL[7083.473626] remove /devices/virtual/block/md0 (block)
UDEV [7083.475440] remove /devices/virtual/bdi/9:0 (bdi)
KERNEL[7083.484140] add /devices/virtual/bdi/9:0 (bdi)
KERNEL[7083.484782] add /devices/virtual/block/md0 (block)
UDEV [7083.485216] add /devices/virtual/bdi/9:0 (bdi)
UDEV [7083.488284] change /devices/virtual/block/md0 (block)
UDEV [7083.499367] change /devices/virtual/block/md0 (block)
KERNEL[7083.508459] change /devices/virtual/block/loop0 (block)
UDEV [7083.509181] change /devices/virtual/block/md0 (block)
UDEV [7083.515422] remove /devices/virtual/block/md0 (block)
UDEV [7083.528049] change /devices/virtual/block/loop0 (block)
UDEV [7083.531441] add /devices/virtual/block/md0 (block)
KERNEL[7083.551131] change /devices/virtual/block/loop1 (block)
UDEV [7083.567953] change /devices/virtual/block/loop1 (block)
KERNEL[7083.591765] change /devices/virtual/block/loop2 (block)
UDEV [7083.625259] change /devices/virtual/block/loop2 (block)
KERNEL[7083.633389] change /devices/virtual/block/loop3 (block)
UDEV [7083.652052] change /devices/virtual/block/loop3 (block)
KERNEL[7083.666807] change /devices/virtual/block/loop4 (block)
UDEV [7083.686840] change /devices/virtual/block/loop4 (block)
KERNEL[7083.700199] change /devices/virtual/block/loop5 (block)
UDEV [7083.728246] change /devices/virtual/block/loop5 (block)
KERNEL[7083.741776] change /devices/virtual/block/loop6 (block)
UDEV [7083.763122] change /devices/virtual/block/loop6 (block)
KERNEL[7083.775143] change /devices/virtual/block/loop7 (block)
UDEV [7083.789863] change /devices/virtual/block/loop7 (block)
KERNEL[7083.861960] change /devices/virtual/block/loop0 (block)
UDEV [7083.871309] change /devices/virtual/block/loop0 (block)
KERNEL[7083.900120] change /devices/virtual/block/loop0 (block)
KERNEL[7083.900996] change /devices/virtual/block/loop1 (block)
UDEV [7083.911511] change /devices/virtual/block/loop0 (block)
UDEV [7083.912274] change /devices/virtual/block/loop1 (block)
KERNEL[7083.966790] change /devices/virtual/block/loop1 (block)
KERNEL[7083.967754] change /devices/virtual/block/loop2 (block)
UDEV [7083.979239] change /devices/virtual/block/loop1 (block)
UDEV [7083.979539] change /devices/virtual/block/loop2 (block)
KERNEL[7084.008355] change /devices/virtual/block/loop2 (block)
KERNEL[7084.009243] change /devices/virtual/block/loop3 (block)
UDEV [7084.020182] change /devices/virtual/block/loop2 (block)
UDEV [7084.020669] change /devices/virtual/block/loop3 (block)
KERNEL[7084.058466] change /devices/virtual/block/loop3 (block)
KERNEL[7084.059510] change /devices/virtual/block/loop4 (block)
UDEV [7084.070194] change /devices/virtual/block/loop3 (block)
UDEV [7084.071165] change /devices/virtual/block/loop4 (block)
KERNEL[7084.108374] change /devices/virtual/block/loop4 (block)
KERNEL[7084.109179] change /devices/virtual/block/loop5 (block)
UDEV [7084.120583] change /devices/virtual/block/loop5 (block)
UDEV [7084.120631] change /devices/virtual/block/loop4 (block)
KERNEL[7084.158432] change /devices/virtual/block/loop5 (block)
KERNEL[7084.15
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: /dev/md0 can't be created
2015-03-27 6:06 ` Xiao Ni
@ 2015-04-01 2:53 ` NeilBrown
2015-04-02 2:52 ` Xiao Ni
0 siblings, 1 reply; 6+ messages in thread
From: NeilBrown @ 2015-04-01 2:53 UTC (permalink / raw)
To: Xiao Ni; +Cc: linux-raid
[-- Attachment #1: Type: text/plain, Size: 5310 bytes --]
On Fri, 27 Mar 2015 02:06:21 -0400 (EDT) Xiao Ni <xni@redhat.com> wrote:
>
> I'm lucky, I reproduced it again and I ran the command udevadm monitor > monitor before test.
> I'll put it in as an attachment.
>
> I found there is a not whole message in the last line.
>
> Xiao
The line:
UDEV [7083.531441] add /devices/virtual/block/md0 (block)
confirms that udev saw an 'add' event for /dev/md0.
That should be enough for udev to create the device node.
If it doesn't, you need to look into udev and find out why it doesn't.
I can't really help you there - I don't find udev very easy to debug.
NeilBrown
>
> ----- Original Message -----
> > From: "Xiao Ni" <xni@redhat.com>
> > To: "NeilBrown" <neilb@suse.de>
> > Cc: linux-raid@vger.kernel.org
> > Sent: Thursday, March 26, 2015 3:36:35 PM
> > Subject: Re: /dev/md0 can't be created
> >
> > Hi Neil
> >
> > I can reproduce it now. Do you want me to run udevadm monitor before the
> > test?
> > And I checked the /var/log/messages, it show the information:
> >
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-2>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-3>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-4>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-5>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-6>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-7>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-9>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-8>
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-7 operational as
> > raid disk 5
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-6 operational as
> > raid disk 4
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-5 operational as
> > raid disk 3
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-4 operational as
> > raid disk 2
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-3 operational as
> > raid disk 1
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-2 operational as
> > raid disk 0
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: allocated 0kB
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: raid level 5 active with 6
> > out of 7 devices, algorithm 2
> > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid456: discard support disabled due
> > to uncertainty.
> > Oct 20 19:59:59 ibm-z10-25 kernel: Set
> > raid456.devices_handle_discard_safely=Y to override.
> > Oct 20 19:59:59 ibm-z10-25 kernel: md0: detected capacity change from 0 to
> > 1881145344
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: recovery of RAID array md0
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: minimum _guaranteed_ speed: 1000
> > KB/sec/disk.
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: using maximum available idle IO
> > bandwidth (but not more than 200000 KB/sec) for recovery.
> > Oct 20 19:59:59 ibm-z10-25 kernel: md: using 128k window, over a total of
> > 306176k.
> > Oct 20 19:59:59 ibm-z10-25 systemd-udevd: inotify_add_watch(7, /dev/md0, 10)
> > failed: No such file or directory
> >
> > Xiao
> >
> > ----- Original Message -----
> > > From: "NeilBrown" <neilb@suse.de>
> > > To: "Xiao Ni" <xni@redhat.com>
> > > Cc: linux-raid@vger.kernel.org
> > > Sent: Wednesday, March 25, 2015 2:35:29 PM
> > > Subject: Re: /dev/md0 can't be created
> > >
> > > On Wed, 25 Mar 2015 02:15:34 -0400 (EDT) Xiao Ni <xni@redhat.com> wrote:
> > >
> > > > Hi all
> > > >
> > > > I have encountered so many times, the raid device is created
> > > > successfully, but the directory
> > > > /dev/md0 can't be created. It can't reproduce 100%.
> > > >
> > > > [root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat
> > > > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
> > > > md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3]
> > > > loop2[2] loop1[1] loop0[0]
> > > > 1788416 blocks super 1.2 512K chunks 2 near-copies [7/7] [UUUUUUU]
> > > > bitmap: 0/1 pages [0KB], 65536KB chunk
> > > >
> > > > unused devices: <none>
> > > > [root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0
> > > > ls: cannot access /dev/md0: No such file or directory
> > > >
> > > > The underline devices are loop devices which are created with big
> > > > file.
> > > >
> > > > The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm -
> > > > v3.3.2
> > > > - 21st August 2014)
> > > > I'll try to reproduce this with upstream kernel and mdadm. But I think it
> > > > shouldn't be the problem about kernel.
> > > >
> > > > What do you think I should check for this? And which tool is
> > > > responsible for creating the directory? Maybe
> > > > I can add some log to it to find the reason.
> > > >
> > >
> > > /dev/md0 is created by udev.
> > > Run
> > > udevadm monitor
> > >
> > > to see the events that udev is processing. When and ADD event for "md0" is
> > > processed, /dev/md0 should get created.
> > >
> > > NeilBrown
> > >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> >
[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: /dev/md0 can't be created
2015-04-01 2:53 ` NeilBrown
@ 2015-04-02 2:52 ` Xiao Ni
0 siblings, 0 replies; 6+ messages in thread
From: Xiao Ni @ 2015-04-02 2:52 UTC (permalink / raw)
To: NeilBrown; +Cc: linux-raid
Hi Neil
I think that is enough to say it's not the problem about md. I really be
thankful for you about the analysis.
Best Regards
Xiao
----- Original Message -----
> From: "NeilBrown" <neilb@suse.de>
> To: "Xiao Ni" <xni@redhat.com>
> Cc: linux-raid@vger.kernel.org
> Sent: Wednesday, April 1, 2015 10:53:21 AM
> Subject: Re: /dev/md0 can't be created
>
> On Fri, 27 Mar 2015 02:06:21 -0400 (EDT) Xiao Ni <xni@redhat.com> wrote:
>
> >
> > I'm lucky, I reproduced it again and I ran the command udevadm monitor >
> > monitor before test.
> > I'll put it in as an attachment.
> >
> > I found there is a not whole message in the last line.
> >
> > Xiao
>
> The line:
>
> UDEV [7083.531441] add /devices/virtual/block/md0 (block)
>
> confirms that udev saw an 'add' event for /dev/md0.
>
> That should be enough for udev to create the device node.
> If it doesn't, you need to look into udev and find out why it doesn't.
> I can't really help you there - I don't find udev very easy to debug.
>
> NeilBrown
>
>
> >
> > ----- Original Message -----
> > > From: "Xiao Ni" <xni@redhat.com>
> > > To: "NeilBrown" <neilb@suse.de>
> > > Cc: linux-raid@vger.kernel.org
> > > Sent: Thursday, March 26, 2015 3:36:35 PM
> > > Subject: Re: /dev/md0 can't be created
> > >
> > > Hi Neil
> > >
> > > I can reproduce it now. Do you want me to run udevadm monitor before
> > > the
> > > test?
> > > And I checked the /var/log/messages, it show the information:
> > >
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-2>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-3>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-4>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-5>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-6>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-7>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-9>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: bind<dm-8>
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-7 operational
> > > as
> > > raid disk 5
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-6 operational
> > > as
> > > raid disk 4
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-5 operational
> > > as
> > > raid disk 3
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-4 operational
> > > as
> > > raid disk 2
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-3 operational
> > > as
> > > raid disk 1
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: device dm-2 operational
> > > as
> > > raid disk 0
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: allocated 0kB
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid:md0: raid level 5 active with
> > > 6
> > > out of 7 devices, algorithm 2
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md/raid456: discard support disabled
> > > due
> > > to uncertainty.
> > > Oct 20 19:59:59 ibm-z10-25 kernel: Set
> > > raid456.devices_handle_discard_safely=Y to override.
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md0: detected capacity change from 0
> > > to
> > > 1881145344
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: recovery of RAID array md0
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: minimum _guaranteed_ speed: 1000
> > > KB/sec/disk.
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: using maximum available idle IO
> > > bandwidth (but not more than 200000 KB/sec) for recovery.
> > > Oct 20 19:59:59 ibm-z10-25 kernel: md: using 128k window, over a total of
> > > 306176k.
> > > Oct 20 19:59:59 ibm-z10-25 systemd-udevd: inotify_add_watch(7, /dev/md0,
> > > 10)
> > > failed: No such file or directory
> > >
> > > Xiao
> > >
> > > ----- Original Message -----
> > > > From: "NeilBrown" <neilb@suse.de>
> > > > To: "Xiao Ni" <xni@redhat.com>
> > > > Cc: linux-raid@vger.kernel.org
> > > > Sent: Wednesday, March 25, 2015 2:35:29 PM
> > > > Subject: Re: /dev/md0 can't be created
> > > >
> > > > On Wed, 25 Mar 2015 02:15:34 -0400 (EDT) Xiao Ni <xni@redhat.com>
> > > > wrote:
> > > >
> > > > > Hi all
> > > > >
> > > > > I have encountered so many times, the raid device is created
> > > > > successfully, but the directory
> > > > > /dev/md0 can't be created. It can't reproduce 100%.
> > > > >
> > > > > [root@intel-sugarbay-do-01 create_assemble]# cat /proc/mdstat
> > > > > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
> > > > > md0 : active raid10 loop7[7](S) loop6[6] loop5[5] loop4[4] loop3[3]
> > > > > loop2[2] loop1[1] loop0[0]
> > > > > 1788416 blocks super 1.2 512K chunks 2 near-copies [7/7]
> > > > > [UUUUUUU]
> > > > > bitmap: 0/1 pages [0KB], 65536KB chunk
> > > > >
> > > > > unused devices: <none>
> > > > > [root@intel-sugarbay-do-01 create_assemble]# ls /dev/md0
> > > > > ls: cannot access /dev/md0: No such file or directory
> > > > >
> > > > > The underline devices are loop devices which are created with big
> > > > > file.
> > > > >
> > > > > The kernel I used is RHEL7 (3.10.0-234.el7.x86_64.debug, mdadm -
> > > > > v3.3.2
> > > > > - 21st August 2014)
> > > > > I'll try to reproduce this with upstream kernel and mdadm. But I
> > > > > think it
> > > > > shouldn't be the problem about kernel.
> > > > >
> > > > > What do you think I should check for this? And which tool is
> > > > > responsible for creating the directory? Maybe
> > > > > I can add some log to it to find the reason.
> > > > >
> > > >
> > > > /dev/md0 is created by udev.
> > > > Run
> > > > udevadm monitor
> > > >
> > > > to see the events that udev is processing. When and ADD event for
> > > > "md0" is
> > > > processed, /dev/md0 should get created.
> > > >
> > > > NeilBrown
> > > >
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > >
>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2015-03-25 6:15 ` /dev/md0 can't be created Xiao Ni
2015-03-25 6:35 ` NeilBrown
2015-03-26 7:36 ` Xiao Ni
2015-03-27 6:06 ` Xiao Ni
2015-04-01 2:53 ` NeilBrown
2015-04-02 2:52 ` Xiao Ni
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