Bug 294351
| Summary: | qdisk does not run on multipathed /dev/mapper devices. | ||||||||
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| Product: | Red Hat Enterprise Linux 5 | Reporter: | Wade Mealing <wmealing> | ||||||
| Component: | cman | Assignee: | Christine Caulfield <ccaulfie> | ||||||
| Status: | CLOSED ERRATA | QA Contact: | GFS Bugs <gfs-bugs> | ||||||
| Severity: | medium | Docs Contact: | |||||||
| Priority: | medium | ||||||||
| Version: | 5.0 | CC: | alain.richard, cluster-maint, jzhenyon, rkenna, tao | ||||||
| Target Milestone: | --- | Keywords: | Regression | ||||||
| Target Release: | --- | ||||||||
| Hardware: | All | ||||||||
| OS: | Linux | ||||||||
| Whiteboard: | |||||||||
| Fixed In Version: | RHBA-2007-0575 | Doc Type: | Bug Fix | ||||||
| Doc Text: | Story Points: | --- | |||||||
| Clone Of: | Environment: | ||||||||
| Last Closed: | 2007-11-07 16:59:54 UTC | Type: | --- | ||||||
| Regression: | --- | Mount Type: | --- | ||||||
| Documentation: | --- | CRM: | |||||||
| Verified Versions: | Category: | --- | |||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||
| Embargoed: | |||||||||
| Bug Depends On: | |||||||||
| Bug Blocks: | 294711 | ||||||||
| Attachments: |
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Ok - I think this is related to a CMAN limitation where the device can't be greater than 16 characters wide. Fortuitously, I have a patch to fix the limitation. Created attachment 198431 [details]
Works around length limitation
The correct way to fix this is in cman. Created attachment 199341 [details]
Patch for review
The patch is trivial, libcman was checking the quorum device name against the
maximum cluster name length rather than the maximum cluster member name length.
The latter is 255 characters, the former 15!
Devel ACK for 5.1 Committed to RHEL51 (and built in cman-2.0.73-1) *** Bug 275821 has been marked as a duplicate of this bug. *** An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2007-0575.html |
Description of problem: This problem exists when accessing/setting the quorum disk by label or by device. The quorum disk as specified in cluster.conf is unable to work on /dev/mapper devices. Customers would like the quorum to be on a robust device. Although the quorum can be configured to run on /dev/dm-N, these can change depending on various san related factors. Scenario 1: <quorumd label="test_qdisk" status_file="/tmp/foo" interval="1" min_score="1" tko="10" votes="2"> <heuristic interval="3" program="ping reliable.host.com -c1 -t1" score="1"/> </quorumd> This is problematic, as the qdisk daemon scans through /proc/filesystems and grabs the first match (usually the /dev/sde, not /dev/dm-N) which voids the use case for multipath. A possible (and tested) is to return the last match in the partition list (cman/qdisk/proc.c), not the first, if people have quorum on multipath, the multipath device is probablyl what they want. Scenario 2: <quorumd device="/dev/mapper/whatever" status_file="/tmp/foo" interval="1" min_score="1" tko="10" votes="2"> <heuristic interval="3" program="ping reliable.host.com -c1 -t1" score="1"/> </quorumd> While this device is found, it is not counted towards the votes in cman_tool status. Scenario 3: <quorumd device="/dev/qvg/qlv" status_file="/tmp/foo" interval="1" min_score="1" tko="10" votes="2"> <heuristic interval="3" program="ping reliable.host.com -c1 -t1" score="1"/> </quorumd> Customers may wish to put the quorum on an lvm device (in case they have a failing disk on the cluster node). This works, but using the /dev/mapper/qvg-qlv does not work. Version-Release number of selected component (if applicable): device-mapper-multipath-0.4.7-8.el5 cman-2.0.60-1.el5 How reproducible: Every time Steps to Reproduce: 1. Configure cluster 2. Add qdisk to point to /dev/mapper/Name 3. start cman , start qdisk, note qdisk votes dont count or show in cman_tool nodes. Actual results: Spend some time finding out the various options that work, and wont work. Expected results: devices created by device-mapper to work. Additional information: Tested on 5.1 beta, same results.