Tru 64 question regarding storage.

[Rich Schueler]

I have a customer that is migrating from multiple EMC DMX's to a single EMC DMX. They are debating on how to migrate the data. Their options are:

1. SRDF copy
2. File copy
3. Host based mirroring

If they use SRDF to copy, their will be less FA's to access the data to the hosts which will necessitate changing the LUN numbers on the new DMX. My question is "Will the Tru64 hosts have a problem with the new drives when they try and access them with their LUN numbers having changed?"

Thanks.
Rich
Schueler_Rich@emc.com

[Vladimir Fabecic]

TRU64 will see them as new disks (will create new device files).
But it can be fixed (dfsmgr).
Please answer these:
1. OS version and patch level?
2. Is it stand-alone system or cluster?

[Rob Leadbeater]

Hi Rich,

If your customer has an ADVFS-UTILITIES license for Tru64, and their storage is based on AdvFS domains, that will be by far the easiest method of migrating the data.

That license enables commands, which will enable you to "addvol" a LUN from your new storage to an existing file domain. You can then "rmvol" the old LUNs from the domain, which will copy all the data from the old to the new. This can be done online.

I've used this technique to migrate data between HSG80s and a couple of EVAs in the past, and nobody noticed. The only time you'll need down time is if your boot disks are also on the SAN.

Hope this helps,

Regards,

Rob

[Rich Schueler]

To Vladimir Fabecic, all hosts are running Tru64 5.1B. Some are clustered, and some are not. Some hosts are using AdvFS and some do not.

[Ivan Ferreira]

>>> "Will the Tru64 hosts have a problem with the new drives when they try and access them with their LUN numbers having changed?"

I don't know about EMC, but some storages replicate the UNIT WWN, that is used by Tru64 to assign the device names, other storages not.

If you WWN change when you replicate devices, then you must manually adjust your /etc/fdmns and /etc/fstab directories. For trucluster operating system disks, this is harder and you should follow procedures described in this forum to migrate the storage for truclusters.