[Linux-cluster] Block Size

[Stephen Nelson-Smith <sanelson gmail com>]

Hi,

I have a 1TB LUN on an EMC SAN, which I see in /proc/partitions as emcpowera.

Ultimately I will be sharing this between two, or three machines, but
at present only one is fibre attached.

I propose to create a GFS2 filesystem now, and use it with one machine
until it becomes necessary to share the LUN with the other machines.

The backups/storage engineer from my hostco recommends I use a
blocksize of 128kb to ensure there are no missed alignments on the SAN
that could degrade performance.  128kb sounds *huge* given that the
default is 4k.

Two questions:

Any problems with the recommended approach - ie mkfs.gfs2 first, worry
about clustering later?

Is mkfs.gfs2 -b 131072 really sane?

Thanks,

S.

-- 
Stephen Nelson-Smith
Technical Director
Atalanta Systems Ltd
www.atalanta-systems.com