Why doesn't PPRC and the like work for ROOTVG??

[kont]

Hi people,

we have several LPARs at our primary site and
the equivalent number at the DR site. Although
all data is on DSs and replicated via PPRC to
the DR, IBM does not support the mirroring for
rootvg. As a result we have to mksysb restore
all LPARs everytime we need to replicate some
major change (for small changes we manually
make the configurations at the DR lpars -- still
a considerable overhead).

Does anyone know if this problem *really* exists ??
Why can't I have a rootvg on a PPRCed SAN volume?
Any solutions/experiences ?

Thanks a lot,
K.

 

[sjm2]

Q Does anyone know if this problem *really* exists ??
A Yes it does.

Q Why can't I have a rootvg on a PPRCed SAN volume?
A There's potentially a lot of stuff that's specific to a given AIX image that needs to get changed when you're on a different server - mksysb patches up much of this for you but not all. Think of IP addresses, WWNs and so on ...

Q Any solutions/experiences ?
A You could always ask IBM to support it.

 

[khalidaaa]

IMHO I think there is a way to tell the SAN to replicate LUNs changes over distance if your partition is SAN booted (rootvg is on one of the SAN's LUN).

Regards,
Khalid

 

[hfaix]

This is exactly the DR model I use. However, I do everything using SAN BOOT (on IBM ESS) and PPRC the boot luns to the DR site.

I'm not exactly sure what you're asking. Are you wanting to do an LVM mirror between Datacenters? If so, that's maybe possible if your DC are only about 1 Km part, however any further and I think you'd have problems. If you're saying you want to mirror (using PPRC disk technology) between datacenters and boot the rootvg from the PPRC pair (after breaking the mirror)...that's absolutely possible. I've done it dozens of times.

 

[kont]

Good to hear that. This is exactly what I want to
do: PPRC the rootvg volume and, simply, boot the
DR machine off that.

You sure it works... ?