Cluster migration (system disk) on other storage

[Michail Bondarenko]

Hello,

Have the VMS cluster one system disk for all 4 nodes. Alpha servers (GS1280 and GS80), VMS version 8.2. Using storage tools can to do clone of system disk no shutdown all nodes in cluster. Is it possible to restart one-by-one node from new system disk at other storage? Example: shutdown 1 node from 4 (3 nodes work on old system disk), change bootdev_def on 1 node, boot it from other system disk and e.t.c. At very short time (~1,5-2 hours) cluster will work on different system disks.

[Robert Badar]

If your cluster is using common system disk, it is unable to use two system disks in one cluster at the same time. There are many common files on disk which are used by cluster nodes.

Why you need this ? To migrate to a new system disk ?

[Michail Bondarenko]

Yes, I need migrate on other system disk. But do not want shutdown all cluster.

[Volker Halle · Accepted solution]

Michail,

whether this operation is possible in your cluster and how easy it is, mainly depends on where you've kept all your cluster-common files (SYSUAF, QMGR-database etc.).

You could boot individual systems from the new system disk and still access the 'common' files on the old system disk. Needs a couple of changes in SYLOGICALS.COM on the new disk.

WHY do you want or need to do this ? Maybe there are better ways to achieve what you want to do.

Volker.

[Robert Badar]

You can use other technique. For example to add a new disk to a mirror or shadow and will have remove old one after copy operation finish. If you are increasing size of disk, then you can stretch it as final action.


RB

[Michail Bondarenko]

I need phisically migrate system disk on other storage. Old storage will shutdown. It will one-time operation only :)

PS. All data disk yet migrated on new storage. On old storage system I have connected only boot system disk.

[Volker Halle]

Michael,

and you don't have a shadowed system disk...

Where are your 'common' files ? On the old system disk ? Then it might be impossible to move them to the new disk, while any of the nodes still have those files open on the old disk.

The most problematic file would be the queue manager database, as you can't change/move that with the queue-manager (and queues) running.

Volker.

[Michail Bondarenko]

OK, thank, I am shutdowning all cluster and boot all 4 nodes from clone of old system disk. It will downtime of bussiness system ~1 hour

[Michail Bondarenko]

PS: I don't have a shadowed system disk...

[Jan van den Ende]

Michail,

If you intend to do a full shutdown, then NOW is the time to prepare for a potential future similar action - or perhaps there might come a time to move to IA64 in a gradual way?

So _NOW_ (on the old config) look in SYSLOGICALS.COM.

By default, many files there are specified, but commented out.
Define a new location for them NOW, and have that location that is NOT on the system disk.

The files that are currently open should be
$ CONVERT/SHARE , for the others BACKUP will do.

Now reboot nyour cluster; and from then on you CAN do rolling upgrades, and rolling hardware replacements.

We did this many times (the main reason we could get to > 10 years cluster uptime!)

Good luck.

Proost.

Have one on me.

jpe