[vox-tech] GFS

[Luke Crawford]

Does anyone here have experience with GFS?  I've got a 1Mbps fibrechannel 
san, of a sort that I'm currently using to split out disks to computers 
on an as-needed basis.  Those computers then software-raid the disks and 
overlay LVM and finally export block devices to Xen.

The problem here is hot-migration.  If each user had his/her own disk, or 
if I had one central file server than exported a FC LUN for each disk I 
could simply make that lun available to all servers.   Hot migration would 
work, in that case.

Unfortunately, I have no such file server box, and I don't exactly trust 
the target-mode FC code (and I'm out of power, so I'd prefer not to add 
another server to the mix)

I think GFS does something a little bit like software raid, such that I 
can run gfs on all my servers and access my pool of disks without a 
storage server (well gfs requires a locking server, but a locking server 
seems safer than a storage server to me, and hopefully I can run it on an 
existing box)

I've also looked at luster, and that looks interesting, but it uses a 
multiple storage server approach, and seems to be designed to be accessed 
over the network.  With the low price of 1G fibre channel, I fail to see 
why anyone (that is, anyone who's needs can not be met by NFS over 
100Mbit)  would still access storage over ethernet;  1G fibre gives you 
faster and more reliable disk than iscsi or similar over 1G ethernet, and 
it's cheaper than 1G ethernet.  (unless you go with consumer-grade 
switches;  but most of those can't reliably push 1Gbit...  even then, the 
going rate for silkworm 2400 8-port fibre switches is under $100, and 
1G QLA2200 cards can be had for as little as $10/each in quantity.. I'm 
waiting for a big shipment right now)

Luster seems to have significantly fewer users and less documentation 
than GFS, so that's what I'm trying first (that and the main objection to 
GFS seems to be "It sucks over IP/ethernet"  I don't care about that; I 
use fibre)


So yeah,  I'm wondering if anyone has used GFS, and if it's usable/stable 
under 2.6 kernels.  Much of what I've read on the net is marketing 
bullshit.