LVM and HBA's

[KPS]

I have an N-4000 that I plan on moving one of my 2 HBA's on this server to a different SBA and slot number. These HBA Cards connect my server to EMC External Disk. Right now, both HBA's are on SBA 0 and I plan on moving one to SBA 1 so I have one of each on both SBA's for Bus Redundancy and maybe even some more balanced i/o. I know this will change the c#t#d# on my disk that is connected through the HBA that I'm moving. What will I have to do to have LVM recognize all of the disk to VG associations after the fact??? Since I'm running PowerPath, does anyone know if Powerpath will take care of the recognizing of the new paths??

[Steven E. Protter]

I suspect the way to go is vgexport the volume group prior to the change and vgimport it after.

This will take out however any custom naming you've done with the lvcreate -n name command.

Seems however the only way to deal with this.

If you do this command:
strings /etc/lvmtab

You are going to see that the volume groups are quite dependent on the device numbers.

SEP

[Michael Tully · Accepted solution]

I would be doing a vgexport/vgimport. I would also turn off powerpath for the duration of the change.

e.g. method

Backup

vgexport for each volume group
# vgexport -m myvg.mapfile -v -s /dev/myvg

Once you've hooked eveything up
# vgimport -m myvg.mapfile -v -s -p /dev/myvg
if everything looks okay
# # vgimport -m myvg.mapfile -v -s /dev/myvg
for each group

Have a look at the man pages.

Regards
Michael
"When I have trouble spelling, it's called fat finger syndrome"