Can I access EMC disks from LVM Maintenance Mode (hpux -lm)

[Stuart Abramson]

Can I read EMC disks on a Tachyon card from LVM maintenance mode?

Or only "internal" and SCSI-cabled disks?

The Tach driver doesn't start until run-level 2. If you reboot to LVM Maintenance Mode does it start the Tach driver?

[Pete Randall]

Stuart,

I think you answered your own question when you said "The Tach driver doesn't start until run-level 2". I highly doubt that you would be able to access them in LVM maintenance mode. And why would you need to?


Pete

[Duncan Edmonstone · Accepted solution]

Sorry Peter, but you can... You can access all your disks from LVM maintenance mode - I've done this on systems which are setup for SAN boot on both XP and EMC storage.

As for why you would want to - well in my case it was beecause I needed to reconstruct a root VG after doing a SAN switch migration (brocade to cisco) where disk hardware paths changed.

I'm not sure what the rc2.d tach driver script does - but I don;t think it enables the driver...

HTH

Duncan

[Stuart Abramson]

We're moving our servers and Symms to a new Data Center. New LAN IP Address and new SAN switches. New SAN switch => new cX numbers on the disks.

I want to set up the disks without the applicaton starting, and some of the applications here start in rc2.d, which is where the fc_td driver initializaiton script starts.

So, if I boot to "lm" then I can set up the disks without Oracle starting.

I'm going to try this tomorrow morning, so I'll know for sure.

[Duncan Edmonstone]

Stuart,

If your not actually booting off the SAN then I think single user mode would probably be better for you rather than maintenance mode - all maintenance mode does is allow you to make offline changes to vg00, which if thats not on the SAN won't matter. I'd go with hpux -is for single user mode instead.

HTH

Duncan

[Pete Randall]

I stand corrected. Thanks, Duncan!


Pete

[Stuart Abramson]

Well, I just came back from testing LVM Maintenance Mode and it worked - I could see, read and write EMC disks. I had the usual problems:
o...I had to activate vg00 and mount all the file systems.
o...The host name wasn't defined.
o...My regular path wasn't right.
o...Some other stuff..

But it worked. The Tachyon drivers were initiated, etc.

It never occurred to me to test single user mode. Do you think that would work? I just can't believe the FC drivers would be set up...

[Steven E. Protter]

Single User mode will work.

You should not have to manually activate vg00 if its on local disk.

My standard procedure after single user mode:

mount /var
mount /usr

This lets me use vi and I can do system administraion on the command line like I'm used to.

This mode will also let you fire up the the tachyon drivers by using the startup scripts in /sbin/init.d

SEP

[Mic V.]

Stuart,

Just an idea for the future -- I have most of my apps set up with a file/variable in /etc/rc.config.d/foo and a variable test in /sbin/init.d/foo (similar to many HP apps, and in the way mentioned in the template file). That way, I just tweak something like:

START_ORACLE=0

in /etc/rc.config.d/oracle and voila! No Oracle and I can do whatever I want to the disks.

Mic