Re: [PATCH] ENBD for 2.5.64

[Matt Mackall <mpm@selenic.com>]

On Tue, Mar 25, 2003 at 09:40:44PM -0500, Jeff Garzik wrote:
> Peter T. Breuer wrote:
> >"Justin Cormack wrote:"
> >>And I am intending to write an iscsi client sometime, but it got
> >>delayed. The server stuff is already available from 3com.
> >
> >
> >Possibly, but ENBD is designed to fail :-). And networks fail.
> >What will your iscsi implementation do when somebody resets the
> >router? All those issues are handled by ENBD. ENBD breaks off and
> >reconnects automatically. It reacts right to removable media.
> 
> Yeah, iSCSI handles all that and more.  It's a behemoth of a 
> specification.  (whether a particular implementation implements all that 
> stuff correctly is another matter...)

Indeed, there are iSCSI implementations that do multipath and
failover.

Both iSCSI and ENBD currently have issues with pending writes during
network outages. The current I/O layer fails to report failed writes
to fsync and friends.

> BTW, I'm a big enbd fan :)  I like enbd for it's _simplicity_ compared 
> to iSCSI.

Definitely. The iSCSI protocol is more powerful but _much_ more
complex than ENBD. I've spent two years working on iSCSI but guess
which I use at home..

-- 
Matt Mackall : http://www.selenic.com : of or relating to the moon