[CentOS] Re: Planning Mail Server (with low resources)

Wed Dec 7 23:13:07 UTC 2005
Bryan J. Smith <thebs413 at earthlink.net>

Aleksandar Milivojevic <alex at milivojevic.org> wrote:
> (Almost) everything I wrote in this thread was from
> perspective of getting something done inexpensively.
> That is what OP asked in the first place. Suggesting
> a tape drive that costs several thousands of dollars 
> (not to mention prices of autoloaders),

If you visit the site every weekday, autoloaders for older
drives are _useless_.  I.e., it's better to go with an LTO-3
than buy an LTO-1 with an autoloader.

Remember, leverage _on-line/near-line_ fixed disk with
_off-line_ tape.  That means for sub-100GB, you are only
sending 1-2 tapes/month off-site _maximum_.

Now given the price of LTO-1 drives and media, it's really a
$1.2K entry point for a drive and 8 tapes that will give you
1-2 years of _off-line_ rotation.  The problem is that too
many people use tape for _everything_.  _Only_ use tape for
off-lining data.

If you're only backing up 40GB, then consider a few 80GB 2.5"
notebook hard drives instead.  They are far more tolerant of
Gs and off-line period than commodity 3.5" disks.

> and then $50-100 for each tape clearly is not what he
> can afford.

Depends on his tape rotation.

Again, I hadn't realized that 100GB (200GB 2:1) LTO-1 was now
approaching $25.

> There are cheaper drives and tapes (such as 8mm and 4mm),

Sorry, 8mm is pretty vendor splittered.  You've got AIT and
VXA (IIRC).  Going back a bit, you then have Exabyte 8mm and
Mammoth.  In any case, not worth it.

Yes, 4mm DAT is multi-vendor, but it's really aged and
_slow_.  By the time you pay $500 for a 36GB (72GB 2:1) DAT72
drive, you're half-way to an AIT-2, VXA-2 or -- now that I
re-educated myself -- LTO-1 drive (definitely go LTO-1 over
AIT or VXA for the same price).

> but those are so unreliable (and not really archival) it
> is not worth even considering them.

Unreliable by who's standard?
4mm DAT is pretty damn small and stores very well.
But yes, 4mm and 8mm aren't as good as DLT and LTO.

> Clearly, tapes (good tapes such as (S)DLT and LTO) are
> better for long term archival storage.  The question is,
> does OT needs that?  If all he needs is couple of weeks (or
> months) worth of backup, and no archiving, RAID-1 or
> RAID-10 disk based solution would be way cheaper and easier
> to maintain.

A disk separate from the running/on-line data.
Again, I'd use some 2.5" drives.

> It does no good to OP if you throw at him solutions fortune
> 500 company can afford.

I don't think I was.  I was talking in reference to _other_
comments.

I said AIT-2 or VXA-2 for smaller, single servers that don't
off-line more than 100GB.  Had I known 100GB LTO-1 was now
under $1K with tapes approaching $25, I wouldn't have even
mentioned AIT-2 or VXA-2.

> Those are way out of reach for him.

"Out-of-reach" is relative.  You should realize that 40% of
your server budget _is_ disaster recovery.  If you don't,
then you're one of the people in the 90% statistic when a
disaster hits.  ;->

> If he wrote "hey, I have this smoking cluster of brand new
> dual core Xeons with terrabytes of SAN based storage". 
Sure,
> I'd suggest some nice backup system. 

Hey, remember the _context_ of _each_ response.
Thank you.  ;->

> Remember, he has an older PIII with 40 gig drive, and
obviously
> no budget for any upgrades of that system.

Then use a couple of 2.5" drives.

> I assume when time comes for him to think about backing it
up,
> his budget ain't gonna be much better (and even if he gets
a
> lot of $$$ for backup, does he really need an expensive
smoking
> tape drive, or will couple of cheap reduntant hard drives
fit
> the bill).

3.5" hard drives are _never_ a good idea because of the G
issues.  Yes, rotating them in every few weeks helps the
off-line issue, but there's still the G issue that will creep
into bad sectors.

> Well, actually, the time to think about backing up his
email
> server is right now, before there are any users on it.  So
> that's way I suggested couple of cheap(er) ways to do it.

I think everything needs to be taken in the context they were
presented.  A lot of tangents were thrown off by many people.


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