Shared block device

[Charles Steinkuehler]

Billy Crook wrote:
>>From what I gathered, I would have to use a shared block device, and a
> journaling filesystem to solve that problem.
> 
> On 3/11/07, *Jonathan Hutchins* <hutchins at tarcanfel.org
> <mailto:hutchins at tarcanfel.org>> wrote:
> 
>     If I understand what you're after, sharing the drive via NFS and
>     mounting it
>     in the appropriate place in the secondary filesystem would be the
>     easiest
>     thing to do.  Actual hardware level sharing using SAN architecture would
>     involve expensive hardware as far as I know.

As mentioned, GFS will let multiple servers mount the same block device
without massive filesystem corruption.  That just leave the 'shared
block device' portion, which is traditionally handled by some sort of SAN.

If you don't feel like shelling out bucks for a pre-packaged solution,
you can coerce linux into exporting raw block devices via iSCSI (SCSI
over IP) or ATAoE (ATA over Ethernet).  Presto!  Instant Po' Man's SAN!

The number of linux boxen required, the performance level, and the
ancillary 'glue' required (ie: switches, GigE/10Gig NICs - possibly with
TCP off-load engines, etc) can vary widely, based on performance
requirements, how much $$$ you want to spend, and how many points of
failure are tolerable.

-- 
Charles Steinkuehler
charles at steinkuehler.net