Bug 433768
| Summary: | [RFE] mirror allocation policies for multiple storage systems | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 5 | Reporter: | Bryn M. Reeves <bmr> |
| Component: | lvm2 | Assignee: | Alasdair Kergon <agk> |
| Status: | CLOSED ERRATA | QA Contact: | Cluster QE <mspqa-list> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 5.0 | CC: | agk, cmarthal, coughlan, cww, dwysocha, fnadge, heinzm, iannis, jbrassow, jcapel, jwest, mbroz, prockai, riek, tao |
| Target Milestone: | beta | Keywords: | FutureFeature, Reopened, Triaged |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | lvm2-2.02.84-1 | Doc Type: | Enhancement |
| Doc Text: |
This field is the basis of the errata or release note for this bug. It can also be used for change logs.
The Technical Note template, known as CCFR, is as follows:
Cause
What actions or circumstances cause this bug to present.
Consequence
What happens when the bug presents.
Fix
What was done to fix the bug.
Result
What now happens when the actions or circumstances above occur.
Note: this is not the same as the bug doesn’t present anymore.
|
Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-07-21 10:51:00 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: | 504871, 554476, 687919 | ||
What I had in mind was 1. Tag PVs to group them - can already be done - no code change required. 2. New allocation policy that comes after 'cling' and only considers devices that have a PV tag matching every PV used so far in the stripe; 3. New allocation policy that follows 2 above and only considers devices that have a PV tag matching the last PV used in the stripe. The code already supports repeated allocation attempts with looser selection criteria, and within the allocation loop, we'd just be adding a tag-matching check. Don't know if we need both 2 and 3, but the decision can be shaped when we look at the code - one of them could turn out harder to do: I think there is existing code structure to match the last PV used in the stripe, but I'm not sure about matching the whole of it. Development Management has reviewed and declined this request. You may appeal this decision by reopening this request. This enhancement request was evaluated by Red Hat Product Management for inclusion a Red Hat Enterprise Linux minor update release. Red Hat does not currently plan to provide this enhanced functionality in a Red Hat Enterprise Linux minor update for currently deployed products. With the goal of minimizing risk of change for deployed systems, and in response to customer and partner requirements, Red Hat takes a conservative approach when evaluating enhancements for inclusion in minor updates for currently deployed products. The primary objectives of update releases are to enable new hardware platform support and to resolve critical defects. For more information on Red Hat Enterprise Linux maintenance policies, please consult: http://www.redhat.com/security/updates/errata/ Red Hat values your feedback and will take this enhancement request into consideration for future major releases of Red Hat Enterprise Linux. This request was evaluated by Red Hat Product Management for inclusion in the current release of Red Hat Enterprise Linux. Unfortunately, Red Hat is unable to address this request in the current release. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux. Refining this a little, a new lvm.conf setting allocation/cling_by_tag_list. If undefined, code functions like now. If set, a new 'cling_by_tag' policy kicks in after 'cling' which requires that each stripe being extended on a PV that has one or more PV tags that match the ones in the list (incl wildcards) only extends the stripe into space on a PV with a matching PV tag. Exact details to be determined when writing the code, choosing the easiest-to-code options. This seems to make sense as a straightforward extension of 'cling'. It will only look at the preceding segment when matching tags, which should be fine for people using it in the way intended where there'll be a common tag through all the PV segments. Although implemented as a separate 'cling_by_tag' policy, it is entirely internal to the tools and comes automatically if you use 'cling' and have the config file setting defined: you can't select it and it never appears in report/xxdisplay output. See bug 504871 for details. This request was evaluated by Red Hat Product Management for inclusion in the current release of Red Hat Enterprise Linux. Because the affected component is not scheduled to be updated in the current release, Red Hat is unfortunately unable to address this request at this time. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux. This request was erroneously denied for the current release of Red Hat Enterprise Linux. The error has been fixed and this request has been re-proposed for the current release. 2.02.77 Fixed in lvm2-2.02.84-1.el5 Here is a list of 9 cling/cling_by_tags cases that I tested on both 5.7 and 6.1 and their results. Based on comment #19 of 6.1 bug 504871, further development for this feature is to be done for 6.2 and 5.8 (like adding lvconverts and lvcreates). ### Cases 1-7 were done with the following cling tag list in lvm.conf: cling_tag_list = [ "@A", "@B" ] ### Case 1. Mirror created w/ --alloc flag and enough PVs with tags for the extension to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 0 A /dev/sdc1 taft lvm2 a- 135.66G 0 B /dev/sdd1 taft lvm2 a- 135.66G 71.33G B /dev/sde1 taft lvm2 a- 135.66G 135.66G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 71.33G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A [root@taft-01 ~]# lvcreate --alloc cling_by_tags -m 1 -n mirror -L 100G --nosync taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# lvextend --alloc cling_by_tags -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Logical volume mirror successfully resized [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 200.00G mirror_mlog 50.11 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdg1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdd1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) ### Case 2. Mirror created w/ --alloc flag and *not* enough PVs with tags for the extension to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 135.66G A /dev/sdc1 taft lvm2 a- 135.66G 135.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G C /dev/sde1 taft lvm2 a- 135.66G 135.66G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G C /dev/sdh1 taft lvm2 a- 135.66G 135.66G C [root@taft-01 ~]# lvcreate -m 1 -n mirror -L 100G --nosync --alloc cling taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# lvextend --alloc cling -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Insufficient suitable allocatable extents for logical volume mirror: 32940 more required [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# lvextend --alloc cling_by_tags -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Insufficient suitable allocatable extents for logical volume mirror: 32940 more required [root@taft-01 ~]# lvextend -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Insufficient suitable allocatable extents for logical volume mirror: 32940 more required ### Case 3. Mirror created w/o --alloc flag and *not* enough PVs with tags for the extension to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 135.66G A /dev/sdc1 taft lvm2 a- 135.66G 135.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G C /dev/sde1 taft lvm2 a- 135.66G 135.66G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G C /dev/sdh1 taft lvm2 a- 135.66G 135.66G C [root@taft-01 ~]# lvcreate -m 1 -n mirror --nosync -L 100G taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwi-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwi-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# lvextend -L +100G --alloc cling taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Insufficient suitable allocatable extents for logical volume mirror: 32940 more required [root@taft-01 ~]# lvextend -L +100G --alloc cling_by_tags taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Insufficient suitable allocatable extents for logical volume mirror: 32940 more required [root@taft-01 ~]# lvextend -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Logical volume mirror successfully resized [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwi-a- 200.00G mirror_mlog 50.15 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdd1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sde1(0) [mirror_mlog] taft lwi-ao 4.00M /dev/sdh1(0) ### Case 4. Mirror created w/ --alloc flag and enough PVs with tags for the extension to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 135.66G A /dev/sdc1 taft lvm2 a- 135.66G 135.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G B /dev/sde1 taft lvm2 a- 135.66G 135.66G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A [root@taft-01 ~]# lvcreate --alloc cling -n mirror -L 100G --nosync -m 1 taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# lvextend -L +100G --alloc cling taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Logical volume mirror successfully resized [root@taft-01 ~]# lvextend -L +100G --alloc cling_by_tags taft/mirror Extending 2 mirror images. Extending logical volume mirror to 300.00 GB Insufficient suitable allocatable extents for logical volume mirror: 14680 more required [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 200.00G mirror_mlog 51.04 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdg1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdd1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) ### Case 5. Mirror created w/o --alloc flag and enough PVs with tags for the extension to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 135.66G A /dev/sdc1 taft lvm2 a- 135.66G 135.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G B /dev/sde1 taft lvm2 a- 135.66G 135.66G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A [root@taft-01 ~]# lvcreate -m 1 -n mirror --nosync -L 100G taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwi-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwi-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# lvextend --alloc cling -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Logical volume mirror successfully resized [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwi-a- 200.00G mirror_mlog 50.20 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdg1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdd1(0) [mirror_mlog] taft lwi-ao 4.00M /dev/sdh1(0) ### Case 6. Simple creation w/ --alloc flag and enough PVs with tags for the creation to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 135.66G A /dev/sdc1 taft lvm2 a- 135.66G 135.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G C /dev/sde1 taft lvm2 a- 135.66G 135.66G B /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A [root@taft-01 ~]# lvcreate -m 1 --alloc cling -L 200G --nosync -n mirror taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created # Note that the PV tags were ignored [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 200.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft iwi-ao 200.00G /dev/sdd1(0) [mirror_mimage_1] taft iwi-ao 200.00G /dev/sde1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdc1(16470) ### Case 7. Simple creation w/ --alloc flag and enough PVs with tags for the creation to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 135.66G A /dev/sdc1 taft lvm2 a- 135.66G 135.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G C /dev/sde1 taft lvm2 a- 135.66G 135.66G B /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A [root@taft-01 ~]# lvcreate -m 1 --alloc cling_by_tags -L 200G --nosync -n mirror taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created # Note that the PV tags were ignored [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 200.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft iwi-ao 200.00G /dev/sdd1(0) [mirror_mimage_1] taft iwi-ao 200.00G /dev/sde1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdc1(16470) ### Cases 8-9 were done with *no* cling tag list in lvm.conf: ### Case 8. Mirror created w/o --alloc flag and enough PVs with tags for the extension to work [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 0 A /dev/sdc1 taft lvm2 a- 135.66G 0 B /dev/sdd1 taft lvm2 a- 135.66G 71.33G B /dev/sde1 taft lvm2 a- 135.66G 71.33G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A [root@taft-01 ~]# lvcreate -m 1 -n mirror --nosync -L 100G taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwi-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwi-ao 4.00M /dev/sdh1(0) # Should this have worked without matching tagged legs? [root@taft-01 ~]# lvextend --alloc cling_by_tags -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Logical volume mirror successfully resized [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwi-a- 200.00G mirror_mlog 50.10 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdd1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sde1(0) [mirror_mlog] taft lwi-ao 4.00M /dev/sdh1(0) ### Case 9. Mirror created w/ --alloc flag and enough PVs with tags for the extension to work [root@taft-01 ~]# lvcreate -m 1 -n mirror --alloc cling --nosync -L 100G taft WARNING: New mirror won't be synchronised. Don't read what you didn't write! Logical volume "mirror" created [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 100.00G mirror_mlog 100.00 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft iwi-ao 100.00G /dev/sdb1(0) [mirror_mimage_1] taft iwi-ao 100.00G /dev/sdc1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) [root@taft-01 ~]# pvs -a -o +pv_tags /dev/sd[bcdefgh]1 PV VG Fmt Attr PSize PFree PV Tags /dev/sdb1 taft lvm2 a- 135.66G 35.66G A /dev/sdc1 taft lvm2 a- 135.66G 35.66G B /dev/sdd1 taft lvm2 a- 135.66G 135.66G B /dev/sde1 taft lvm2 a- 135.66G 135.66G C /dev/sdf1 taft lvm2 a- 135.66G 135.66G C /dev/sdg1 taft lvm2 a- 135.66G 135.66G A /dev/sdh1 taft lvm2 a- 135.66G 135.66G A # Should this have worked? [root@taft-01 ~]# lvextend --alloc cling -L +100G taft/mirror Extending 2 mirror images. Extending logical volume mirror to 200.00 GB Logical volume mirror successfully resized [root@taft-01 ~]# lvs -a -o +devices LV VG Attr LSize Log Copy% Devices mirror taft Mwl-a- 200.00G mirror_mlog 50.11 mirror_mimage_0(0),mirror_mimage_1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdb1(0) [mirror_mimage_0] taft Iwi-ao 200.00G /dev/sdd1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sdc1(0) [mirror_mimage_1] taft Iwi-ao 200.00G /dev/sde1(0) [mirror_mlog] taft lwl-ao 4.00M /dev/sdh1(0) Marking verified for 5.7 even though this feature is not yet complete. Hi, am assigned to edit the errata that describes this bugzilla entry and need you to briefly state the cause, consequence, fix, result for this bug. If possible, use the Technical Notes field at the top of of this bugzilla entry. Try to use the already copied Cause, Consequence, Fix, Result, Structure. Just skip what you think unnecessary. Many thanks, Florian
Technical note added. If any revisions are required, please edit the "Technical Notes" field
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New Contents:
This field is the basis of the errata or release note for this bug. It can also be used for change logs.
The Technical Note template, known as CCFR, is as follows:
Cause
What actions or circumstances cause this bug to present.
Consequence
What happens when the bug presents.
Fix
What was done to fix the bug.
Result
What now happens when the actions or circumstances above occur.
Note: this is not the same as the bug doesn’t present anymore.
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 therefore 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-2011-1071.html 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 therefore 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-2011-1071.html |
Description of problem: LVM2 already enforces the constraint that the images within a mirror be stored on distinct PVs. In an environment with multiple PVs that may or may not be part of the same failure domain (e.g. multiple SAN enclosures) it is useful to also enforce the constraint that images be stored across multiple domains (enclosures). For e.g. in a two-way mirror consisting of three linear segments: +---+---+---+ | a | b | c | +---+---+---+ | d | e | f | +---+---+---+ If two independent storage enclosures are available, ideally, (a,b,c) and (d,e,f) should be placed on different enclosures. This allows one whole SAN to fail without compromising the mirror. Currently this allocation policy has to be specified manually via PV command line arguments. It would be advantageous to be able to tag PVs as belonging to the same failure domain allowing the allocation policy for lvcreate/lvconvert to automatically allocate images to independent physical storage. Version-Release number of selected component (if applicable): lvm2-2.02.27-2.el4 Additional info: