[Info-vax] Finding out how many nodes have a disk mounted?

[Michael Moroney]

osuvman50 at gmail.com writes:

>Is there a robust way an application can tell if a disk volume is mounted on
>multiple nodes in a cluster? The obvious things like lib$getdvi(..,
>DVI$_MOUNTCNT,) don't do that. Spawning a "show device xxx" and parsing the
>result doesn't fall under the category of robust.

>I'm toying with adding WAL (write ahead logging) support to my SQLite port. In
>unixland, WAL comes with the restriction that it doesn't work on NFS shares or
>other distributed file systems because it uses shared memory to share log state
>information. Disallowing WAL mode for any databases residing on disks marked 
>available to the cluster in OpenVMS seems overly restrictive since the volume
>may only be mounted on one node.

In addition to the DVI item Steve mentioned, this is also available from
DCL's F$GETDVI(disk,"MOUNTCNT_CLUSTER")

$ write sys$output f$getdvi("DSA1","MOUNTCNT_CLUSTER")
2
$

Not in the documentation, I am not sure why.