symmetrical cluster

[prashanth]

Hi ,

we have symmetrical cluster and we are planning to replace the san switch . It will keeep the device path as it is or it will change. What will be the impact on cluster. How to keep the symmetrical cluster as it is. How to keet the disk device path as it is.

Thanks!!

[Pramod M]

Prashanth,

There will be no changes in the device path if you are changing the SAN switch with keeping the cabling diagram without changes. Keep the fiber cables labeld and seperated for Switch1 & 2. Check the Controller, SAN Switch, Host HBA firmware compatibility.

Pramod

[Stephen Doud]

Legacy device files (eg /dev/dsk/c2t5d2) are prone to change if the n_port ID changes.  11.31 persistent/agile device files are not affected by location in the backplane or switch changes (per pg 2 in http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c01906504/c01906504.pdf).

Keep the domain ID (0-255) of the new SAN switch the same as the outgoing switch.

Play it safe... create LVM map files of all cluster-aware volume groups, in case pathing changes and you have to re-import the volume groups.

# for vg in `strings /etc/lvmtab | grep -v -E 'disk|dsk' | sed 's_/dev/__g'`
> do
> vgexport -pvs -m /etc/lvmconf/$vg.map /dev/$vg
> done

Copy the map files for the cluster-aware VGs to the other nodes too.