Just my 1/50th of a dollar, but...
While I'd also go for the xServe, if I WERE doing this with minis, I'd
simply attach the "backup" machine via FW target mode, and have
SuperDuper or something of the sort making a backup daily (or more
often). Production machine fails, simply shut them both down,
disconnect the FW cable, and reboot.
Easy enough way to have a "warm" spare with minimal downtime.
Taylor
On 12/18/09 10:38 AM, Nichols, Jared - 1160 - MITLL wrote:
Interesting. Though, I’d worry about my
eventual outlay of funding and effort to be more than just Doing It
Right The First Time™. Don’t forget to include the amount of time it
takes to get each iteration implemented as part of your cost structure.
How are you handling replication of the OS and settings between one
Mini and the other?
Me, I’d be much more apt to get that low-end Xserve set up the way I
needed it and be done with it. Then, I can focus my limited resources
to other things that need my attention. Email is a tried and true
technology. It should be fire and forget.
Your solution is quite interesting and could work out quite well.
“Effort sink” is the red flag that’s going up in my head, that’s all.
j
On 12/18/09 10:06 AM, "David Emery" <email@hidden> wrote:
Clearly, a single Mini is not going to be
very fault tolerant. But...
Consider the following for less than $3k:
2x mini servers
1x Drobo* or similar RAID enclosure with a bunch of disk drives in it.
Mini #1 fails. You unplug the RAID enclosure and plug it into Mini #2.
Note this is a good transition strategy, as you buy the first Mini, the
RAID enclosure, and then add the 2nd Mini if that matches your
cost/reliability figure. Or you move from the single Mini + Drobo to low
end XServe + Drobo, and that's probably $4k-$5k. If that works, you
upgrade the disk subsystem.
dave
* I'm citing Drobo as an example, frankly I'd probably go with the OWC
less expensive RAID enclosure. The advantage of the DROBO is you can put
different sized disks into it. But if I'm setting up a mail server from
scratch, I'll buy 4-5x of the same kind of drives.
And yes, a RAID enclosure is no substitute for a full data
replication/backup approach.
Nichols, Jared - 1160 - MITLL wrote:
>
> I'm not quite sure how many 9's you really need for an email
server.
>
> To me, a lot :) Though, it’s difference of environments. If your
> number 1 concern is data retention, then sure a Mini can do it.
> Though, I’m not sure what kind of setup you’re going with if a
drive
> failure will end up with you doing a “swap-over from one machine to
> another.” Can you elaborate?
>
> j
>
> On 12/18/09 9:38 AM, "David Emery" <email@hidden> wrote:
>
> I'm not quite sure how many 9's you really need for an email
> server. To
> me the #1 concern is preventing data loss. Past that, a couple
of
> minutes of downtime to do a swap-over from one machine to
another is
> acceptable. The Mini gets us started, it's not a final
solution.
>
> dave
>
> Nichols, Jared - 1160 - MITLL wrote:
> > The thing I’d worry about with the Mini server is not
computational
> > load as I’m sure it could handled hundreds of email
accounts without
> > much of a problem – the tech specs look like it could
handle it
> > (though perhaps I’d like more than 4GB of RAM).
> >
> > What I’d /really /worry about is redundancy. There’s only
1 NIC, so
> > you can’t bond them for interface redundancy and there’s
only 1 power
> > supply. Also, the drive setup is not ideal for
reliability-required
> > situations. Only two drives means that you’re doing a
RAID 1 if
> you’re
> > looking for redundancy. And, in that case, if one drive
fails, you’ve
> > still got downtime because you need to crack the case
open to replace
> > the drive. In that case, I’d worry about computational
power –
> > rebuilding the RAID array while trying to keep email
service up and
> > speedy may be a bit taxing.
> >
> > What the real server-class hardware gets you (independent
of Mac vs
> > Windows) is hardware redundancy and the ability to
hot-swap
> > components. While the price of the Mini is /extremely/
> attractive, for
> > something as critical as email in an office where that
downtime isn’t
> > acceptable (if it is, by all means get one) I wouldn’t go
for it.
> >
> > Don’t let the price blind you to the serviceability and
reliability
> > requirements :)
> >
> > j
> >
> > On 12/17/09 6:00 PM, "David Emery" <email@hidden>
wrote:
> >
> > Has anyone seen any numbers/projections/rules-of-thumb
for how many
> > email users a Mac Mini Server whose primary duty is email
server
> (POP,
> > IMAP, SMPT) will handle? I'm interested in computational
load, not
> > disk
> > space... What motivated this was an exchange with a
corporate IT
> > person. "We're investing in Exchange upgrades." "Yeah,
but I bet
> > you're spending a lot more than the $1k for a Mini
Server..." The
> fair
> > question is whether a Mini Server would handle the load.
> >
> > dave
> >
> > --
> > David Emery, DSCI, supporting PdM SW Integration, PM NSI
> > 703 298 3473 (office/cell), 703 272 7496 (fax)
> >
> > _______________________________________________
> > Do not post admin requests to the list. They will be
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> >
> >
> > ---
> > Jared F. Nichols
> > Desktop Engineer, Infrastructure and Operations
> > Information Services Department
> > MIT Lincoln Laboratory
> > 244 Wood Street
> > Lexington, Massachusetts 02420
> > 781.981.5436
> >
>
> --
> David Emery, DSCI, supporting PdM SW Integration, PM NSI
> 703 298 3473 (office/cell), 703 272 7496 (fax)
>
>
>
>
> ---
> Jared F. Nichols
> Desktop Engineer, Infrastructure and Operations
> Information Services Department
> MIT Lincoln Laboratory
> 244 Wood Street
> Lexington, Massachusetts 02420
> 781.981.5436
>
--
David Emery, DSCI, supporting PdM SW Integration, PM NSI
703 298 3473 (office/cell), 703 272 7496 (fax)
---
Jared F. Nichols
Desktop Engineer, Infrastructure and Operations
Information Services Department
MIT Lincoln Laboratory
244 Wood Street
Lexington, Massachusetts 02420
781.981.5436
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