RE: [Xen-devel] iSCSI

["Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>]

> Is there a introducing comparison of the different network 
> blockdevice techniques like NBD/ENBD/GNBD, DRDB or iSCSI? You 
> seem to prefer iSCSI
> - why?

GNBD is definitely the best of the *NBD's. 

DRDB is good for network mirroring.

iSCSI is the preferred option if you have access to a hardware target,
otherwise you might use GNBD.
 
> Is network blockdevice sharing (that's meant with 
> "multipath", right?) necessary for "xm migrate"?

You don't require multipath for migration, e.g. if your rootfs is
available via GNBD or iSCSI. If you're trying to do something fancy with
network mirroring then DRDB works OK, but true in-kernel mutipath
support would probably be better.

> > BTW: gnbd works great, but I wish it used checksums over 
> and above the 
> > ip csum / ethernet crc32.
> 
> As the ethernet checksum is (afaik) over the hole frame it 
> should be ok as long as GNDB is done within a L2 segment, correct?

Depends how paranoid you are.
Having block-level CRCs makes me feel safer.

Ian


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