[CentOS] Server Virtualization

Wed Sep 19 21:09:00 UTC 2007
Mark D. Foster <mark at foster.cc>

Paul Heinlein wrote:
> On Tue, 18 Sep 2007, Flaherty, Patrick wrote:
>
>> If I had the time, I'd like to try using Xen with an OpenSolaris ZFS
>> iSCSI target as shared storage, but alas I do not have that time.
>
> FWIW, I've had good luck compiling and running the iSCSI target from
> http://iscsitarget.sourceforge.net/ on CentOS 5. There aren't all the
> bells and whistles of ZFS, I suppose, but it's pretty simple to set
> up. Also, given gigabit ethernet and a decent switch, its bonnie++
> numbers aren't bad at all.
>
Apples and oranges, though.  iSCSI is networked block storage. It does
not case what filesystem you lay on it. As someone who learned this the
hard way, it is not enough to have iSCSI to support live vm migration.
If you are look to setup 2+ xen hosts and live migrate amongst them
(known as vmotion in vmware-land) you need _shared_ storage filesystem,
and ext3 is not that nor is zfs. See
http://en.wikipedia.org/wiki/List_of_file_systems#Shared_disk_file_systems
for a list of FS that would suitable to lay on iSCSI for this purpose.

-- 
Said one park ranger, 'There is considerable overlap between the 
 intelligence of the smartest bears and the dumbest tourists.'
Mark D. Foster, CISSP <mark at foster.cc>  http://mark.foster.cc/