[Bug 1486370] Re: ISST-LTE: not all mpath device files are symbol link
Mathieu Trudel-Lapierre
mathieu.tl at gmail.com
Mon Feb 1 14:44:35 UTC 2016
** Description changed:
[Impact]
Minimal impact, this is limited to aesthetic issues; devices should if possible all be actual block device nodes rather than symlinks.
[Test case]
1) ls -l /dev/mapper
2) Reboot, try again.
+
+ Also:
+ while true; do kpartx -d -p -part /dev/dm-2;udevadm settle; kpartx -a -p -part /dev/dm-2; udevadm settle;done
+
+ Or:
+ while true; do multipath -F; multipath; done
+
[Regression potential]
Timing issues may cause delays in generating device nodes or symlinks due to the need for multipath-tools, device-mapper and udev to synchronize.
---
== Comment: #0 - Ping Tian Han <pthan at cn.ibm.com> - 2015-07-21 23:38:48 ==
---Problem Description---
Some mpath devices in /dev/mapper are symbol links to /dev/dm-<n>, but there are exceptions:
% ls -l /dev/mapper
total 0
crw------- 1 root root 10, 236 Jul 21 20:46 control
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath0 -> ../dm-0
brw------- 1 root root 252, 4 Jul 21 20:46 mpath0-part1
brw------- 1 root root 252, 6 Jul 21 20:46 mpath0-part2
brw------- 1 root root 252, 7 Jul 21 20:46 mpath0-part3
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath1 -> ../dm-1
brw-rw---- 1 root disk 252, 2 Jul 21 20:46 mpath2
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath3 -> ../dm-3
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath4 -> ../dm-5
mpath2 isn't a symbol link.
% sudo dmestup info mpath2
sudo: dmestup: command not found
% sudo dmsetup info mpath2
Name: mpath2
State: ACTIVE
Read Ahead: 256
Tables present: LIVE
Open count: 0
Event number: 4
Major, minor: 252, 2
Number of targets: 1
UUID: mpath-36005076304ffc69f0000000000000469
% sudo dmsetup info /dev/dm-2
Name: mpath2
State: ACTIVE
Read Ahead: 256
Tables present: LIVE
Open count: 0
Event number: 4
Major, minor: 252, 2
Number of targets: 1
UUID: mpath-36005076304ffc69f0000000000000469
Contact Information = Ping Tian Han/pthan at cn.ibm.com, Chanh H
Nguyen/chnguyen at us.ibm.com
---uname output---
Linux onyxlp2 3.19.0-22-generic #22~14.04.1-Ubuntu SMP Wed Jun 17 10:03:39 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux
Machine Type = na
---Steps to Reproduce---
1. install ubuntu on onyxlp2, which has mpath device
2. ls /dev/mapper, see some mpath device file isn't symbol link
Userspace tool common name: na
The userspace tool has the following bit modes: 64-bit
Userspace rpm: na
Userspace tool obtained from project website: na
== Comment: #6 - Mauricio Faria De Oliveira <mauricfo at br.ibm.com> - 2015-08-18 12:33:17 ==
This shouldn't be a problem at all.
Either symlinks to the dm devices or block devices which refer to them directly (via major:minor number) will work.
It isn't ideal, though.
== Comment: #7 - Mauricio Faria De Oliveira <mauricfo at br.ibm.com> - 2015-08-18 12:35:34 ==
BTW, that expectation is per the SRU policy.
And the problem cause is likely a race involving udev rules (multipath &
kpartx), and possibly multipathd.
--
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https://bugs.launchpad.net/bugs/1486370
Title:
ISST-LTE: not all mpath device files are symbol link
Status in multipath-tools package in Ubuntu:
Fix Released
Status in multipath-tools source package in Trusty:
In Progress
Bug description:
[Impact]
Minimal impact, this is limited to aesthetic issues; devices should if possible all be actual block device nodes rather than symlinks.
[Test case]
1) ls -l /dev/mapper
2) Reboot, try again.
Also:
while true; do kpartx -d -p -part /dev/dm-2;udevadm settle; kpartx -a -p -part /dev/dm-2; udevadm settle;done
Or:
while true; do multipath -F; multipath; done
[Regression potential]
Timing issues may cause delays in generating device nodes or symlinks due to the need for multipath-tools, device-mapper and udev to synchronize.
---
== Comment: #0 - Ping Tian Han <pthan at cn.ibm.com> - 2015-07-21 23:38:48 ==
---Problem Description---
Some mpath devices in /dev/mapper are symbol links to /dev/dm-<n>, but there are exceptions:
% ls -l /dev/mapper
total 0
crw------- 1 root root 10, 236 Jul 21 20:46 control
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath0 -> ../dm-0
brw------- 1 root root 252, 4 Jul 21 20:46 mpath0-part1
brw------- 1 root root 252, 6 Jul 21 20:46 mpath0-part2
brw------- 1 root root 252, 7 Jul 21 20:46 mpath0-part3
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath1 -> ../dm-1
brw-rw---- 1 root disk 252, 2 Jul 21 20:46 mpath2
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath3 -> ../dm-3
lrwxrwxrwx 1 root root 7 Jul 21 20:46 mpath4 -> ../dm-5
mpath2 isn't a symbol link.
% sudo dmestup info mpath2
sudo: dmestup: command not found
% sudo dmsetup info mpath2
Name: mpath2
State: ACTIVE
Read Ahead: 256
Tables present: LIVE
Open count: 0
Event number: 4
Major, minor: 252, 2
Number of targets: 1
UUID: mpath-36005076304ffc69f0000000000000469
% sudo dmsetup info /dev/dm-2
Name: mpath2
State: ACTIVE
Read Ahead: 256
Tables present: LIVE
Open count: 0
Event number: 4
Major, minor: 252, 2
Number of targets: 1
UUID: mpath-36005076304ffc69f0000000000000469
Contact Information = Ping Tian Han/pthan at cn.ibm.com, Chanh H
Nguyen/chnguyen at us.ibm.com
---uname output---
Linux onyxlp2 3.19.0-22-generic #22~14.04.1-Ubuntu SMP Wed Jun 17 10:03:39 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux
Machine Type = na
---Steps to Reproduce---
1. install ubuntu on onyxlp2, which has mpath device
2. ls /dev/mapper, see some mpath device file isn't symbol link
Userspace tool common name: na
The userspace tool has the following bit modes: 64-bit
Userspace rpm: na
Userspace tool obtained from project website: na
== Comment: #6 - Mauricio Faria De Oliveira <mauricfo at br.ibm.com> - 2015-08-18 12:33:17 ==
This shouldn't be a problem at all.
Either symlinks to the dm devices or block devices which refer to them directly (via major:minor number) will work.
It isn't ideal, though.
== Comment: #7 - Mauricio Faria De Oliveira <mauricfo at br.ibm.com> - 2015-08-18 12:35:34 ==
BTW, that expectation is per the SRU policy.
And the problem cause is likely a race involving udev rules (multipath
& kpartx), and possibly multipathd.
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