[Xen-users] RAID + DRBD + iSCSI + Multipath

[Kevin DeGraaf <kevin@xxxxxxxxxxxx>]

Hello,

We've been using Xen on several servers with direct-attached storage for 
a number of years.  Now we're looking to buy more Xen servers and 
re-purpose two of the older ones as SANs to hold the domU filesystems, 
in order to achieve redundancy and live migration ability.  I'm looking 
for comments on our proposed design.
SAN 1 - existing server w/ 4 GB, 2x Opteron 270
SAN 2 - existing server w/ 16 GB, 2x Xeon 5120

Each SAN box:
  * 3ware RAID-5 -> DRBD -> iSCSI Enterprise Target
  * Heartbeat with physical STONITH cables
  * Debian stable
  * Eth0 for management, eth1 for DRBD, eth2 for iSCSI

Multiple Xen physical servers
  * 24 GB, 2x Xeon quad-core
  * Small disks w/ RAID-1 for the dom0
  * Debian stable
  * Eth0 for the main network, eth1 for iSCSI

Optionally:
  * Second iSCSI network (eth3 on SAN boxes, eth2 on Xen boxes) using 
multipath.
The idea is that we can take down (or lose) Xen servers and migrate (or 
restart) domUs on an alternate server easily.  If we lose one of the 
SANs, the other one will STONITH and take over iSCSI service 
transparently.  If we go with multipathing, we can even lose one storage 
switch and still not have any downtime.
Does this sound reasonable, or have I missed something and/or made 
things too complicated?  Can anyone offer recommendations for the 
dedicated iSCSI gigabit switch(es)?  Any other comments?
Thanks.

--
Kevin DeGraaf

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users