RHCS6: Mirror/unmirror a GFS2 volume
Article Number: 203 | Rating: Unrated | Last Updated: Sun, Jun 3, 2018 9:45 AM
RHCS: Mirror/unmirror a GFS2 volume
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# Tested on RHEL 6
# Mirroring # ------------------------------------------------------------------------------------------ # Given a simple gfs2 logical volume (note that type is 'linear' and all extents are # currently on a single physical volume): lvdisplay -m /dev/gfstestvg/gfstestlv01 --- Logical volume --- LV Path /dev/gfstestvg/gfstestlv01 LV Name gfstestlv01 VG Name gfstestvg LV UUID Ih02E9-62kI-JmLz-HSSJ-3fhn-t0wd-r73UxX LV Write Access read/write LV Creation host, time myserver, 2014-10-09 15:24:28 +0200 LV Status available # open 0 LV Size 512.00 MiB Current LE 128 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:7 --- Segments --- Logical extent 0 to 127: Type linear Physical volume /dev/shared/sdd <--- Current physical volume Physical extents 0 to 127 # It makes no sense mirroring disk on current physical volume so we have to look for a # PV belonging to current volume group with enough free space to allocate extents. # If needed, add a new physical volume to the volume group pvs PV VG Fmt Attr PSize PFree /dev/sda2 rootvg lvm2 a-- 15.50g 3.50g /dev/shared/sdc gfsvg lvm2 a-- 6.00g 0 /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g <--- current physical volume /dev/shared/sde gfstestvg lvm2 a-- 2.00g 2.00g <--- pv with free extents /dev/shared/sdf lvm2 a-- 1.00g 1.00g # Let's mirror (one copy) our volume lvconvert -m1 gfstestvg/gfstestlv01 /dev/shared/sde Shared cluster mirrors are not available. # Ooops, something went wrong! # In fact, we need cmirrord daemon to be running in order to mirror and make work correctly # any gfs2 mirrored volume. It tracks mirror log information on a cluster and relies on # 'cman' which must be running for cmirrord to function ('clvmd' is also required). # Install it if needed, "yum install cmirror" # We start 'cmirrord', then, and enable the automatic start at boot time: service cmirrord start Starting cmirrord: [ OK ] chkconfig cmirrord on # Then, we are ready for mirroring operation: lvconvert -m1 gfstestvg/gfstestlv01 /dev/shared/sde gfstestvg/gfstestlv01: Converted: 3.1% gfstestvg/gfstestlv01: Converted: 5.1% [...] gfstestvg/gfstestlv01: Converted: 97.3% gfstestvg/gfstestlv01: Converted: 100.0% # Our mirrored volume lvs LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert gfstestlv01 gfstestvg mwi-a-m-- 512.00m gfstestlv01_mlog 100.00 <---- lv_depot gfsvg -wi-ao--- 6.00g lv_home rootvg -wi-ao--- 1.00g lv_opt rootvg -wi-ao--- 1.00g lv_root rootvg -wi-ao--- 1.00g lv_swap rootvg -wi-ao--- 2.00g lv_tmp rootvg -wi-ao--- 2.00g lv_usr rootvg -wi-ao--- 4.00g lv_var rootvg -wi-ao--- 1.00g lvdisplay -m /dev/gfstestvg/gfstestlv01 [...] --- Segments --- Logical extent 0 to 127: Type mirror Mirrors 2 Mirror size 128 Mirror log volume gfstestlv01_mlog Mirror region size 512.00 KiB Mirror original: Logical volume gfstestlv01_mimage_0 Logical extents 0 to 127 Mirror destinations: Logical volume gfstestlv01_mimage_1 Logical extents 0 to 127 pvs --segments -o+lv_name,seg_start_pe,segtype PV VG Fmt Attr PSize PFree Start SSize LV Start Type [...] /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_0] 0 linear <---- /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.49g 0 128 [gfstestlv01_mimage_1] 0 linear <---- /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.49g 128 1 [gfstestlv01_mlog] 0 linear <---- /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.49g 129 382 0 free /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1020.00m 0 255 0 free # If we wanted to create a 3-side mirror (for example). We need two disks in our volume # group with enough free space to allocate the mirror copies: pvs PV VG Fmt Attr PSize PFree /dev/sda2 rootvg lvm2 a-- 15.50g 3.50g /dev/shared/sdc gfsvg lvm2 a-- 6.00g 0 /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g /dev/shared/sde gfstestvg lvm2 a-- 2.00g 2.00g <---- /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1020.00m <---- # Let's mirror (two copies) our volume lvconvert -m2 gfstestvg/gfstestlv01 /dev/shared/sde /dev/shared/sdf gfstestvg/gfstestlv01: Converted: 4.7% gfstestvg/gfstestlv01: Converted: 12.5% [...] gfstestvg/gfstestlv01: Converted: 93.8% gfstestvg/gfstestlv01: Converted: 100.0% # Check lvdisplay -m /dev/gfstestvg/gfstestlv01 [...] --- Segments --- Logical extent 0 to 127: Type mirror Mirrors 3 Mirror size 128 Mirror log volume gfstestlv01_mlog Mirror region size 512.00 KiB Mirror original: Logical volume gfstestlv01_mimage_0 Logical extents 0 to 127 Mirror destinations: Logical volume gfstestlv01_mimage_1 Logical extents 0 to 127 Logical volume gfstestlv01_mimage_2 Logical extents 0 to 127 pvs --segments -o+lv_name,seg_start_pe,segtype PV VG Fmt Attr PSize PFree Start SSize LV Start Type [...] /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_0] 0 linear <---- /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_1] 0 linear <---- /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 504.00m 0 128 [gfstestlv01_mimage_2] 0 linear <---- /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 504.00m 128 1 [gfstestlv01_mlog] 0 linear <---- /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 504.00m 129 126 0 free # Un-mirroring # ------------------------------------------------------------------------------------------ # Given a three side gfs2 logical volume (note that type is 'mirror' and extents are # on three different physical volume, original + 2 mirror copies): lvdisplay -m /dev/gfstestvg/gfstestlv01 --- Logical volume --- LV Path /dev/gfstestvg/gfstestlv01 LV Name gfstestlv01 VG Name gfstestvg LV UUID L35bR5-1sCH-aiK5-joH4-h674-mIvx-xZ3lx5 LV Write Access read/write LV Creation host, time cientouno, 2014-10-09 15:26:49 +0200 LV Status available # open 0 LV Size 512.00 MiB Current LE 128 Mirrored volumes 3 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:7 --- Segments --- Logical extent 0 to 127: Type mirror Mirrors 3 Mirror size 128 Mirror log volume gfstestlv01_mlog Mirror region size 512.00 KiB Mirror original: Logical volume gfstestlv01_mimage_0 Logical extents 0 to 127 Mirror destinations: Logical volume gfstestlv01_mimage_1 Logical extents 0 to 127 Logical volume gfstestlv01_mimage_2 Logical extents 0 to 127 pvs --segments -o+lv_name,seg_start_pe,segtype PV VG Fmt Attr PSize PFree Start SSize LV Start Type [...] /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_0] 0 linear <---- /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_1] 0 linear <---- /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 504.00m 0 128 [gfstestlv01_mimage_2] 0 linear <---- /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 504.00m 128 1 [gfstestlv01_mlog] 0 linear <---- /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 504.00m 129 126 0 free # Let's reduce one of the copies: lvconvert -m1 gfstestvg/gfstestlv01 /dev/shared/sdf Logical volume gfstestlv01 converted. # Check lvdisplay -m /dev/gfstestvg/gfstestlv01 [...] --- Segments --- Logical extent 0 to 127: Type mirror Mirrors 2 Mirror size 128 Mirror log volume gfstestlv01_mlog Mirror region size 512.00 KiB Mirror original: Logical volume gfstestlv01_mimage_0 Logical extents 0 to 127 Mirror destinations: Logical volume gfstestlv01_mimage_1 Logical extents 0 to 127 pvs PV VG Fmt Attr PSize PFree /dev/sda2 rootvg lvm2 a-- 15.50g 3.50g /dev/shared/sdc gfsvg lvm2 a-- 6.00g 0 /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1020.00m <---- Reduced pvs --segments -o+lv_name,seg_start_pe,segtype | grep gfstestvg /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_0] 0 linear /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g 0 128 [gfstestlv01_mimage_1] 0 linear /dev/shared/sde gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1016.00m 0 128 0 free /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1016.00m 128 1 [gfstestlv01_mlog] 0 linear /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1016.00m 129 126 0 free # And, finally, completely remove the mirror: lvconvert -m0 gfstestvg/gfstestlv01 /dev/shared/sde Logical volume gfstestlv01 converted. # Check lvdisplay -m /dev/gfstestvg/gfstestlv01 --- Logical volume --- LV Path /dev/gfstestvg/gfstestlv01 LV Name gfstestlv01 VG Name gfstestvg LV UUID L35bR5-1sCH-aiK5-joH4-h674-mIvx-xZ3lx5 LV Write Access read/write LV Creation host, time cientouno, 2014-10-09 15:26:49 +0200 LV Status available # open 0 LV Size 512.00 MiB Current LE 128 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:7 --- Segments --- Logical extent 0 to 127: Type linear Physical volume /dev/shared/sdd Physical extents 0 to 127 pvs PV VG Fmt Attr PSize PFree /dev/sda2 rootvg lvm2 a-- 15.50g 3.50g /dev/shared/sdc gfsvg lvm2 a-- 6.00g 0 /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g /dev/shared/sde gfstestvg lvm2 a-- 2.00g 2.00g <---- Reduced /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1020.00m pvs --segments -o+lv_name,seg_start_pe,segtype | grep gfstestvg /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 0 128 gfstestlv01 0 linear /dev/shared/sdd gfstestvg lvm2 a-- 2.00g 1.50g 128 383 0 free /dev/shared/sde gfstestvg lvm2 a-- 2.00g 2.00g 0 511 0 free /dev/shared/sdf gfstestvg lvm2 a-- 1020.00m 1020.00m 0 255 0 free |
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