How to break root disk Mirror in VxVM
Hi All
bash-3.00# vxprint -g rootdg -vh rootvol
TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0
v rootvol root ENABLED 60821952 - ACTIVE - -
pl rootvol-01 rootvol ENABLED 60821952 - ACTIVE - -
sd rootdg01-B0 rootvol-01 ENABLED 1 0 - - Block0
sd rootdg01-02 rootvol-01 ENABLED 60821951 1 - - -
pl rootvol-02 rootvol ENABLED 60821952 - ACTIVE - -
sd rootdg02-01 rootvol-02 ENABLED 60821952 0 - - -
bash-3.00# df -h /
Filesystem size used avail capacity Mounted on
/dev/vx/dsk/bootdg/rootvol
29G 19G 9.4G 67% /
1)
From above configuration we see root file system is configured on volume rootvol which is a mirror. Now i'd like to break the mirror and keep the mirror copy for backout purpose as i will be upgrading on the actual root disk. I do not want to delete the plexes or the mirror copy.
Suppose in SVM, d0 is a mirror and d10 and d20 are its submirrors, we issue metadetach d0 d20 command to detach the submirror.
How do we accomplish the same in the above VxVM configuration ?
2)
Plex rootvol-02 has only 1 subdisk rootdg02-01, whereas Plex rootvol-01 has 2 subdisks rootdg01-B0 and rootdg01-02.
What is the significance of having 2 subdisks for the plex rootvol-01 ? If the Plex rootvol-01 is a mirrored copy of another plex rootvol-02 then the size and number of subdisks in each plex should be the same or not ?
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use-nvramrc?=true
nvramrc=devalias vx-rootdg01 /pci@1f,700000/scsi@2/disk@0,0:a
devalias vx-rootdg02 /pci@1f,700000/scsi@2/disk@1,0:a
3)
Once the root volume plex has been disassociated can we still use both the above listed device aliases to boot OS from ok prompt ?
ok> boot vx-rootdg01
ok> boot vx-rootdg02
Thank you everybody for your response as always. Response is highly appreciated.
Regards,
Danish.
Hi Danish,
Here are you answers
1. A good technote that explains all the steps in order
http://www.symantec.com/docs/TECH37532
Some more similar posts
https://www-secure.symantec.com/connect/forums/breaking-mirror-vxvm-controlled-disk#comment-7166761
https://www-secure.symantec.com/connect/forums/how-break-vrtsvxvm-root-mirror-patching
2. If you carefully see the subdisk layout, one of subdisk is just 1 block to contain a boot block possibly which is nothing but block 0. Rest of question is answered in links above. Do visit the guide to understand the procedure of how to boot a system from alternate disks
https://sort.symantec.com/public/documents/sfha/6.0/solaris/productguides/html/sf_admin/ch31s02s06s02.htm
3. The alias names are still on OBP & not modified with above process so yes, the alias names should still work.
G