AIX

IBM recommend not to mirror the dump lv, I am assuming they are referring to mirroring as part of rootvg for example.

What if I moved the primary dump device to an external SAN disk and mirrored it at a SAN level?

I'm not even sure why they advise to not mirror it, but does anybody have any experience of doing what I mentioned above?

You'd do better to have a primary dump device (lv) on one rootvg disk and a secondary dump device on the other, in case you lose the first.

I don't see much point in trying to dump to a san disk because of the much higher chance of not being able to access it in the case of a panic.

From the lvm redbook:
A mirrored, or copied, logical volume is not supported as the active
dump device. System dump error messages will not be displayed, and
any subsequent dumps to a mirrored logical volume will fail.

HTH

Well the LVM doesn't know whether the storage it gets from SAN is mirrored or not, so that doesn't matter. It treats the disk as any other disk whether mirrored or not on SAN.

The reason for asking is because we use SAN boot, we have rootvg on one disk on our production site and another disk for rootvg on our DR site - these are mirrored at LVM level (so lg_dumplv is not mirrored, it exists only on the production disk). While testing DR recovery this caused a bit of a problem when we failed back, not a huge problem, but enough to make us think 'there must be a better way'.

If we could move the primary dump device to disk that was mirrored at a SAN level we would have no problem at all.