on 16:28 Tue 08 Feb, Jason Brown (jason.brown@xxxxxxxxxxxxxxxxxxxxx) wrote:
> On 02/07/2011 05:09 PM, Dr. Ed Morbius wrote:
> > on 15:19 Mon 07 Feb, Ross Walker (rswwalker@xxxxxxxxx) wrote:
> >> On Mon, Feb 7, 2011 at 2:36 PM, Dr. Ed Morbius <dredmorbius@xxxxxxxxx> wrote:
> >>> on 13:56 Mon 07 Feb, Jason Brown (jason.brown@xxxxxxxxxxxxxxxxxxxxx) wrote:
> >>>> I am currently going through the process of installing/configuring an
> >>>> iSCSI target and cannot find a good write up on how to prepare the disks
<...>
> >>> What are you using for your iSCSI target (storage array)?
<...>
> >>> Truth is, there's a lot of flexibility with iSCSI, but not a lot of
> >>> guidance as to best practices that I could find. Vendor docs have
> >>> tended to be very poor. Above is my recommendation, and should
> >>> generally work. Alternate configurations are almost certainly possible,
> >>> and may be preferable.
> >>
> >> If a best practices doc could be handed to you right now, what would
> >> you like it to contain?
> >
> > <grin>
> >
> > I've got about 35 pages of that document sitting on my local HD now.
> > Negotiating with management about releasing some of it in some form or
> > another.
<...>
> >> I would be happy to draft something up and put it on a wiki somewhere,
> >> but I would need a list of talking points to start with.
> >
> > How's this do you?
>
> In our configuration, we are going to have our iSCSI targets and
> initiators all connected to the same layer 3 switch and isolate the
> iSCSI traffic on separate networks. Would it be beneficial to also set
> up multipath for this as well?
That's pushing the limits of my knowledge/understanding.
Multipath aggregates multiple pathways to a data store. In the case of
the Dell equipment mentioned in my post, there are two controllers, with
4 TOE/NIC cards each, offering 8 pathways to each target storage LUN.
Multipath aggregates all 8 pathways to a single target, and provides
both performance and availability enhancements by utilizing these
pathways in turn (defaulting to round-robin sequencing), and presumably
disabling use of any pathway(s) which become unavailable (whether or not
any monitoring/alerting of this failover/fail-out is possible would be
very useful to know).
It's also possible to configure multiple initiator pathways, though in
our case we've already aggregated multiple NICs into a bonded ethernet
device.
>From the description you've provided, I don't think you've got a
multipath configuration. I don't know what would happen if you
attempted to set up multipath, but presuming not too much magic smoke
escapes, I'd be interested in finding out.
Presumably you'd have to configure /etc/multipath.conf appropriately to
pick up the target(s).
--
Dr. Ed Morbius
Chief Scientist When you seek unlimited power
Krell Power Systems Unlimited Go to Krell!
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