[Linux-cluster] GFS and SCSI commands DLOCK/DMEP

[Bryn M. Reeves]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jos Vos wrote:
> Hi,
> 
> The vendor of a cabinet that we have - via two separate SCSI channels -
> connected to two cluster nodes running RH CS and GFS (RHEL4 U4) responds
> to a problem we have as follows:
> 
>    The GFS filesystem require RAID system to support special
>    SCSI commands (DLOCK/DMEP).
> 
> Am I right that this is not true and that only older versions
> of GFS relied on these SCSI commands?
> 
> Thanks,
> 

Hi Jos,

Afaik, yes - these are the ancient history of clustersuite. Take a look
at the paper "Symmetric Cluster Architecture". This talks about the
evolution of locking in clustersuite, from the original DLOCK/DMEP
support, to a DLOCK/DMEP simulator (this went on to become GULM), and
finally to the distributed lock manager (DLM).

http://people.redhat.com/~teigland/sca.pdf

Although the paper is a couple of years old now, it covers this area
quite thoroughly.

Kind regards,

Bryn.

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iD8DBQFFtKh86YSQoMYUY94RAq1eAJ9Vj8aYXmBYFAiUqh8zILKeHGcKfgCffUth
vFtXKPxWsGGvrpqewXaO5ck=
=Xv8L
-----END PGP SIGNATURE-----