how to find raw devices being used

[Ra Jose]

I have a VG vg01 and it has 5 lvols namely
lvol1 thru lvol5.

The lvol1 and lvol2 are filesystems and you
can see them in /etc/fstab and bdf outputs.

The lvol3,lvol4 and lvol5 are not there in fstab nor in mnttab, but hahve filesystem (fstyp shows vxfs) on them.

This server is rp4440 and runs 11iv1 and has Oracle 9i on it.

I checked /dev/vg01 and all lvols are owned by root:sys.

My first impression is that the lvol3 thru lvol5 are used by oracle as raw devices.

If so, then these /dev/vg01/rlvol3 thru rlov5
must be owned by oracle:dba with 660 permission. This is not so in this server.

Is there anyway to check from unix side, how to find out whether /dev/vg01/lvol3 thru lvol5 are used as raw devices by oracle.

Thank you all.
Rajose.

[Steven E. Protter]

Shalom,

Usually I create soft links to make the raw devices visible.

To see what devices are necessary, try and start oracle and check the alert logs. Every device it needs will show up in the logs.

Checking the actual init.ora configuration will also be helpful.

I'd also see no harm in going with your first impression and changing the ownership on the suspected devices. If something else is using them the change will probably error out.


SEP

[spex · Accepted solution]

Hello Rajose,

In your case, it's clear that lvol3-lvol5 are not raw volumes because 'fstyp' reports a filesystem in existence, and because the ownership and mode of the files is not appropriate. To see what is on the lvols, you could always create mountpoints and try to 'mount' them and look around.

In general, symlinks from Oracle datafiles pointing to rlvol device files are a dead giveaway that the database uses raw devices.

PCS

[Sandman!]

Not sure of any way other than peeking at the DBA_DATAFILES view in Oracle to find out which datafiles reside on raw devices. The symbolic link method as suggested by SEP is ingenious.

[Ra Jose]

I had to go to DBA to have them check in their system tables.

Also splex respone of checking filesystem was useful. Since there is filesystem on it, it is obvious that it is not raw device.

Thank you folks.

Rajose.