vgimport question

[KPS]

Hi,

We have a question around vgimport. We're doing SAN Replication from one disksubsystem to another for Disaster Recovery. (These disksubsystems are at different sites)

When and if we need to failover to the DR site, we would use mapfiles from the original site and just vgimport against them to activate VG's and then mount filesystems and such.

The question we have is if we have to list out all the target /dev/dsk/c#t#d# when we do our vgimport if we use the following options with it?

# vgimport -v -s -m /tmp/vg01.map /dev/vg01

Thanks,
/KPS

[sujit kumar singh]

Hi Kapil,


if i understand correctly then you want to do a vgimport using the PV Names of the PV that fall to that VG and using the map file right?

the option is -f but that is mutually exclusive with the -s option so make a point of that

#vgexport -p -v -m /tmp/vgXX.map -f /tmp/vgXX.pvlist /dev/vgXX

this shall create a MAP file /dev/vgXX.map as well as the PV list file that is /tmp/vgXX.pvlist which shall contain all the PVs mentioned that are the part of the VG vgXX.


you can use the same combination of the map file and the PVlist file for the import at the othe place.

rcp/ftp thesw two filess /tmp/vgXX.map and /tmp/vgXX.pvlist on the target system and there do the following ot import

#vgexport /dev/vgXX
#mkdir /dev/vgXX
#mknod /dev/vgXX/group c 64 0xYY0000
make sure that the minor no is kept same on both the Systems and is unique on one system.
#vgimport -v -n /tmp/vgXX.map -f /tmp/vgXX.pvlist /dev/vgXX

regars
sujit

[KPS]

What we're curious about is do we need to list the /dev/dsk/c#t#d# if we use the following syntax on the vgimport:

vgimport -v -s -m /tmp/vg01.map /dev/vg01

Thanks,
/KPS

[KPS]

BTW, i forgot to mention that all the VG info from the failed site's devices would be on the devices at the failover site since that is being replicated over.

Thanks,
/KPS

[sujit kumar singh · Accepted solution]

Hi KPS

vgimport -v -s -m /tmp/vg01.map /dev/vg01

with this syntax you do not need to specify the PV Names.

NOTE:

but please check that the map file /tmp/vg01.map ( you cabn do a cat /tmp/vg01.map ) to have a look has an additional "Word" mentioning the VG-ID. Actually /tmp/vg01.map shall have a VG-ID in that once that is created as the result of the command vgexport -p -v -s -m /tmp/vg01.map /dev/vg01.


note that the command
# vgimport -v -s -m /tmp/vg01.map /dev/vg01

when executed , reads the VG-ID mentioned in the map file /tmp/vg01.map , scans all the disks in the system , probes for the VG-ID of all the Disks being scanned and imports in the VG /dev/vg01 only those PVs that match the VG-ID.


but this can be confusing in case of the BC PVs as after the split the BC Volumes have the same VG-ID.


Please refer to the manpages of the command
vgimport and vgchgid for this.


i am giving the links of the Online Man Pages


http://docs.hp.com/en/B3921-60631/vgchgid.1M.html

and

http://docs.hp.com/en/B3921-60631/vgimport.1M.html


regards
sujit




regards
sujit

[KPS]

Thanks these are SRDF Target devices so not sure if we'll have this issue or not. I guess we'll give it a shot and find out.

Thanks for your responses on this...

Regards,
/KPS