saggar wrote:
> How much it takes for a VG to be mirrored.?
>
> I have a VG(50 disks ,10G each) which containes LV(125G).
>
> It is taking a long time to mirror around 5 hrs.
>
> Is it normal ?
>

If these LUNs are SAN based (as you say) it then depends on how the disk
array connected to the SAN is configured. I have some seen some disk
arrays configured and sliced in lots of lovely ways, then someone comes
along and mirrors a VG when the underlying LUNs are already configured
in a hardware redundant manner i.e. a RAID-5 or RAID-6 configuration so
the VG doesn't need to be mirrored and doing so may introduce
performance issues.

Also some low-end Disk Arrays don't have very large caches or
write-cache is not enabled so if you are mirroring LUNs, the lack of
cache could have an effect.