Missing Logical Volumes

[ST-ISA]

I will attempt to make this as simple and concise as possible.

I have a LUN on an EMC CX300 that is connected to my FC5 box via SAN (Fibre Channel).
I have seperated this LUN into two logical volumes.

Recently, there were some network changes and restructuring, including the SAN. Since this occured, I have lost these logical volumes. Now, it seems as though I can see the disks. They show up as SCSI disks on my box. But, all my logical volume information seems to be gone. Does anyone know of a sure fire way to recover these?

[RomKnight]

do you have EMC powerpath? If so, try powermt config ; powermt display dev=all

Is naviagent running? /etc/init.d/naviagent restart

Is the host logged in/registered in the CX300?

Run vgscan and see if you can see the VG. If so, do a vgchange -ay and then try to mount the LVs

Did you check the logs for errors?

Is the zoning ok on the san switch?

[ST-ISA]

I am not using powerpath, and I do not use naviagent on this particular host. There has been no need to, as the host is manually registered in the CX300. I have attempted vgscan and vgchange already, the volume groups are not detected.

I am unable to check the logs for errors. This box is a loghost, and ALL of the logs are dumped to a socket to a mysql database, which happens to be on the logical volume in question.

[ST-ISA]

Okay, seems as though my multipath device disappeared, I have recovered this, and now vgscan sees the missing VG. Although, now when I try to mount the LVs I get the following:

mount: wrong fs type, bad option, bad superblock on /dev/vgstore/lvlogs,
missing codepage or other error
In some cases useful info is found in syslog - try
dmesg | tail or so



Ignore this, I located the problem and have resolved it.

[RomKnight]

and if you do a fsck to that lvol?

[ST-ISA]

That wasn't the issue. Turns out, the drives still recognized being part of a previous raid array, when I tried to recreate the array, I flubbed up the array type. I corrected that, and everything worked fine. What still puzzles me is why the multipath device disappeared when everything was powered down and moved. My network admins have assured me that the fibre was connected back to the same ports that it was removed from, yet I still lost the multipath device. Upon investigation, I have discovered that I do not have a mdadm.conf file, and I believe this probably has something to do with it. What puzzles me is why this was not created when I initially setup the multipath device.

[RomKnight]

Glad it worked out. Anyway, I think mdadm won't run if you don't have mdadm.conf... Well, at least now you know