Bug 1191935
| Summary: | LVM RAID - Add support for raid level reshaping | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Heinz Mauelshagen <heinzm> |
| Component: | lvm2 | Assignee: | Heinz Mauelshagen <heinzm> |
| lvm2 sub component: | Mirroring and RAID | QA Contact: | cluster-qe <cluster-qe> |
| Status: | CLOSED ERRATA | Docs Contact: | Steven J. Levine <slevine> |
| Severity: | high | ||
| Priority: | high | CC: | agk, cmarthal, heinzm, jbrassow, jkachuck, msnitzer, pasik, prajnoha, prockai, rbednar, slevine, zkabelac |
| Version: | 7.2 | Keywords: | Tracking, Triaged |
| Target Milestone: | rc | ||
| Target Release: | 7.4 | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | lvm2-2.02.169-1.el7 | Doc Type: | Enhancement |
| Doc Text: |
LVM now supports RAID reshaping
LVM now provides support for RAID reshaping. While takeover allows users to change from one RAID type to another, reshaping allows users to change properties such as the RAID algorithm, stripe size, region size, or number of images. For example, a user can change a 3-way stripe to a 5-way stripe by adding two additional devices. Reshaping is available only on top-level logical volumes in single machine mode, and only while the logical volume is not in-use (for example, when it is mounted by a file system).
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-08-01 21:47:18 UTC | Type: | Bug |
| 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: | 1430028 | ||
| Bug Blocks: | 834579, 1189124, 1346081, 1354610, 1394039 | ||
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Description
Heinz Mauelshagen
2015-02-12 09:30:41 UTC
Code's done and being reviewed/integrated. Reshaping is copes with the conversion of the raid layout (e.g. raid5_ls -> raid5_n), the stripe size (e.g. 32k -> 64k) or the number of stripes (e.g. add 3 stripes to a raid set with 5 stripes; same for removing stripes) in a raid set.
Reshaping _never_ changes the raid level!
(Changing the level is a takeover (e.g. raid5_n -> raid0/striped))
Overview of raid LV types (i.e. layout algorithms for data and parity) to test:
raid5_{ls,rs,la,ra,n}
raid6_{zr,nc,nr,ls_6,rs_6,la_6,ra_6,n_6}
raid10(_near)
Dimension of the test matrix for aforementioned levels:
1. convert from/to all the layout variations on each level with the
exception of raid10, where there's only one layout for now
2. convert the stripe size in each of those layouts;
stripe size must be > 4k and < regionsize
3. change the regionsize (lvconvert -R ...) on given RaidLVs
(e.g. to be able to grow the stripesize)
3. convert adding/removing stripes to any of those layouts
(-f option needed with lvconvert to remove stripes;
repeat when reshape finished to remove the freed legs)
4. combine 1-3, ie. convert layout and stripesize at the same time
5. add takeover conversions to the matrix:
- after having changed layout to any _n variants, convert levels down
- raid6_n_6 -> raid5/raid0/raid0_meta/striped
- raid5* -> raid6* (any raid5* layouts directly map to their
raid6 counterparts, e.g. raid5_rs to raid6_rs_6
Add linear -> striped conversions and vice versa to the matrix
Upstream commits e2354ea344c2 to 34caf8317243 Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2017:2222 |