[CentOS] Possible SAN Issue

Thu May 14 14:27:15 UTC 2009
nate <centos at linuxpowered.net>

Jim Perrin wrote:

> This is where LVM shines, because you can simply add another lun, add
> it to your lvm setup, and expand the filesystem on the fly.

Also the OP should look into thin provisioning software that may
be available for his EMC array. In some situations this can eliminate
the need for LVM. For me I still use LVM because it helps when
detecting what paths to use with MPIO. I often create larger(1-2TB)
volumes on the storage array and then create smaller logical volumes
in LVM, then when I need to expand I just expand, no need for new
LUNs. If your data access patterns don't involve large amounts of
writes and then deletes(thin provisioning dedicates storage when it
is written to), then you don't need volume management at all the
array can do it for you.

Most workloads in my experience are friendly with thin provisioning,
some are not. Some vendors have ways to reclaim deleted space as
well to put it back into the storage pool(s) for use by other
systems.

http://searchstorage.techtarget.com/news/column/0,294698,sid5_gci1134713,00.html

nate