Use of VxVM on StorageWorks LUNs(Disks)

[Alzhy]

I have been testing VxVM on HSV/HSG80 SAN connected disks without incident for the past 3 months. I am aware that Veritas does not "officially" support Storage Works disks in the context of rootability, DMP does not work, etc. and some issue with system startup (which is easily fixed..). But aside from these which are realy not critical - it nicely manages the LUNs. DMP we donot need as SecurePath is already there. Raid protection -- is already on the LUNs and we are not booting off these LUNs (roortability)..

My inquiry -- is anyone out there using VxVM in such a similar fashion - ie. using VxVM to carve out LUNs from SAN based arrays (specifically Compaq StorageWorks - EVA and HSG80 based)that already are protected and multi-pathed?


The recipe that we plan to use is still continue with LVM with managing the system/boot disks, utilize a pair of SCSI disks for rootDG and use VxVM for the rest of the LUN's on the SAN. BTW, the "issue" with startup is that SecurePath starts early than VxVM subsystem so if a "work-around script" is not in place, on every HPUX startup - all the DiskGroups from your SecurePath managed LUNs will not automatically come up. Such workaround script can easily be written and should include:

#!/bin/sh
# S888vxvmfix - fix for SecurePath LUNs on VxVM
vxdctl enable
vxvol EvaDG startall
mountall

[Alzhy]

Update:

Yes.. SecurePath Managed LUNS (whether it is from EVA or HSG80) has been supported since SecurePath 3.0C and no lonher require the fix above.

Whether you use base of full VxVM, DMP will not kick in as it will not "see" the pseudo paths and will just ignore the paths. SecurePath will continue to protect your Paths to the StorageWorks LUNS (EVA/HSG80..etc).

Hopefully with HP comes up with FW specially for the current/newgen EVAs so it will work with DMP -- for those sites that use Full VxVM so they would not double spend on SecurePath and Full VxVM..

[Robert-Jan Goossens]

Nelson,

I'm highly interested in this subject. We are about to start the investigation to move to an evaX000 on our Unix environments. Currently we use VXVM DMP to mirror our data over 2 data centers.

If you have more information, or you know where I can find more information I would be very interested, also in respect to the new line of eva products (eva4/6/8000)

Thanks in advance.

Robert-Jan

[Alzhy]

I'd be glad to provide feedback/opinions, etc Robert.

It appears HP's decision to fully adopt VxVM as its preferred Volume Manager is a wise decision as it is the only Volume Manager out there that has no hardware agenda (supported on any array). Sure HP's disk arrays have their own Hardware Based replication/mirroring options (ie. COntinous Access/Bsuiness Copy) BUT those only work with like storage ie. EVA to EVA and XP to XP (although with the 12K its no longer true).

Our decision to go with VxVM was due to the instability we suffered with EVA's as a single array solution. With VxVM we can mirror data to another EVA or to a different array architecture and allow for easier/pain-free storage migration fromone array architecture to another as we've done when we moved from EVAs to XP12K. Post move, we now use EVA5K's as Mirror Copies for backups, tests and DSS..