Software Mirror a Database

[Tim D Fulford]

Ryan

It seems to me that you are familar with LVM terms but not the detail. There is one "GOT YA" (which does NOT effect your service/availability). You cannot simply swap out a duff disk for a new one and expect LVM to sort it out. You need to to a
# vgcfgrestore -n
to restore all the LVM headder & footrt info onto the disk. Then MirrorUX kicks in & does the rest. If you do just swap the disk it will just sit there unused & UNMIRRORED!

Also, you need to monitor LVM to check if a disk has broken. Things like STM, ITO etc can do this but one way to check if your disk is duff is to do
# pvdisplay /dev/dsk/ | grep -i stale
If you continously have stale extents the disk may be duff! (a stale extent is one that has not synced with the mirror)

All the above said disks rarely go wrong, I've NEVER used vgcfgrestore only only occasionally seen stale extents.

Tim