Tru64 5.1B-3 and Fibre based Disk and Tape Libraries

[Adam Garsha]

Tru64 5.1B-3 cluster

If booting from a CD to recover the system, will the fibre based disks be visible? (e.g. loose a disk group in your EVA and then rebuild the disk group and now you are going to recover from tape). Are there special commands that you need to enter to see the drives? (I know there would be work to be done to mount'em up, but I want to know if they will be visible/accesible in hwmgr, etc).

Second question, what if you have fibre based "tape drives" (e.g. a VirtualTapeLibrary), can you see the fibre based tape drives if you boot from the installation CD?

[SAKET_5 · Accepted solution]

Adam,

I haven't recently tried this - so I am answering your question to the best of my recollection abilities from past experience of Tru64 SAN disk accessibility and management:

1. SAN based disks should be visible at the >>> (SRM) layer by virtue of the SRM layer capabilities, i.e. "wwidmgr -show devices". Ofcourse if when a Tru64 host boots off a SAN disk in its usual routine, its the SRM layer that sees the disk via multiple paths (assuming you have multiple fabrics, etc)first. Remember the host OS does not even get initialised at this stage. So, basing on the above I would say once you boot off the recover CD - as long as the SAN Fabric zoning permits the host to communicate to the storage array and ofcourse SSP remains intact for the host's LUs (Logical Units) - you should be able to access them in the usual way.

[Uwe Zessin]

For desaster recovery I would also record the virtual disk's 128-bit WWIDs in advance, because a new initialization of the EVA can easily result in new values. Problem is that Tru64 Unix does a persistent binding based on the LUN WWN.

As far as I can tell (I'm not a T64 administrator), it is possible to recover from this situation using T64 tools, but it looks like this is more work.

[Adam Garsha]

Thanks. Yup all vdisk WWID's documented and updated with every new Vdisk and host. I am confident that the device files would be different for a CD booted OS image.

I'll asign points later. I want to lure a few more posters. The heart of my question is whether or not the booted-from-5.1-b3-install-cd-os-kernel can see fibre based disks and fibre based tape drives.

I've only installed Tru64 truclusters using a local seed disk, so I am not sure if the CD OS image can see fibre or not.

(It will be a few weeks before I can actually try it.)

[Adam Garsha]

I got confirmation elsewhere that the answer is yes, you will be able to see the devices.