VG Mirror - AIX 5.2/ AIX5.3

[smokingranger99]

Hi

I have a question regarding UserVG mirroring on AIX 5.2 and 5.3. We have a userVG with 2 internal disks which is not mirrored. Now we have a need to mirror it. I was thinking of allocating a equal size disk on SAN and using the mirrorvg comamnd. Is it a good practice to mirror a VG on internal disks with SAN disks? Also can the data on two disks be mirrored on one disk ( the one disk size is = the total of two internal disk)?Is there any other method that can be used.

Thanks

 

[sjm2]

Q Is it a good practice to mirror a VG on internal disks with SAN disks?

A What is more important is whether it is usual practice in your organisation. Anything that is unusual is risky from a sysadmin perspective.

The SAN LUNs may already be configured to be highly-available (eg RAID-5) in which case the mirroring is redundant. And if you already have SAN connectivity, wy not just move the data onto the SAN LUN?

Q can the data on two disks be mirrored on one disk?

A With LVM mirroring, yes. Since mirroring is done as a mapping from Logical Partitions to Physical Partitions, there is no necessary one-to-one mapping of (h)disks.

 

[smokingranger99]

Thanks for the reply..