[geeks] The Idea(tm)... Homebrew Terabytes Cheap

[geeks at sunhelp.org]

Take a look at PC Power & Cooling (www.pcpowercooling.com) for
powersupplies.  They make models up to 900watts.
	Nick

On Fri, 13 Apr 2001, Chris Byrne wrote:

> Jody,
> 
> First of all you work for tattered cover? Kick ass, that is the coolset book
> store. I always go every time I'm in Denver, even though the parking is a
> pain (or at least it was last time I was there about a year ago). I think we
> had to park in the safeway down the street and walk over.
> 
> Anyway, managing a huge amount of storage isn't as simple as it seems. While
> I admit they cost far more than they should, there really is a reason that
> large scale storage arrays cost mucho bucks. The biggest problems here are
> bus bandwidth and filesystem management.
> 
> There's just no way you can split up the limited badwidth of a. the system
> bus and b. the drive controllers over that many drives efficiently. I've
> tried sticking 16 drives on a single general purpose system and have it max
> out at less than 5% of the sustained throughput capabilites of each drive.
> 
> And that assumes your bus functions properly with that many devices attached
> to it, and that you don't exceed your cable length limit. I've never tried
> putting that many devices on a single bus before, but my gut feeling is that
> 90+ devices (80 drives, 10 plexes, plus all the SCSI cards and any other
> ancillary cards) isn't going to work.
> 
> Also you are gonna need a HONKING power supply in each box. Up until
> recently I would have said that'd be a problem, but enermax just came out
> with a truly kick ass 650 watt PS with two fans and 16 power taps.
> 
> 
> The other issue is filesystem/volume management (actually add scheduling of
> backups to maximize performance to that as well)
> That's mostly an administrative issue on the order of "do I want to take the
> admin bandwidth to handle volume and backup management manually, or do I
> want to buy expensive volume management software ala veritas, or do I want
> to hack an opensource tool to work in this somewhat exceptional
> environment".
> 
> I went through this last year with StorageWay, and we came to the conclusion
> that with all of the factors weighd in, it's actually cheaper to buy a
> serious storage array than to try and build and maintain one yourself.
> 
> Now if they woyuld jsut make one that didnt cost $250k
> 
> Actually the good news is, you can often find mid range storage arrays on
> EBay for pretty reasonable prices. Add a veritas license, and a machine to
> control the thing, and for the same $20k you were talking about you can have
> a hitachi or EMC (probably a 1 TB array rather than a 3 TB)
> 
> 
> Chris Byrne
> 
> 
> -----Original Message-----
> From: geeks-admin at sunhelp.org [mailto:geeks-admin at sunhelp.org]On Behalf
> Of Jody Stephens
> Sent: Friday, April 13, 2001 13:32
> To: geeks at sunhelp.org
> Subject: [geeks] The Idea(tm)... Homebrew Terabytes Cheap
> 
> 
> Here is the deal. Currently we have about 5 DDS-2 tape
> drives, media we get for ~$15 a pop. Problem, we have
> to keep all of the tapes for 1 year, after that we
> keep month beginnings and month ends. Each machine does
> about 2GB uncompressed.
> 
> So we've been trying to think of way to cut costs (we
> seem to spend >$5000 yearly for tapes including about a
> %10 failure rate). Some of the things I've looked at are
> 
> 1. Buying cheap IDE drives, writing to them, pulling them
> storing them. Actually this works out to about the same
> price, but we get better reliabilty (in theory), quicker
> backups and restores. But we have to deal with HD's, which
> are not exactlly durable. So that is out.
> 
> 2. CD-R. Alright except each machine would span more than
> 1 disc, creating problems if one fails. And dealing with
> all those CD's doesn't sound like fun.
> 
> 3. Optical. Too bloody expensive.
> 
> Sooo... My thought.
> 10 IDE plex at ($460 each)
> 80 WD 40GB drives ($130 each)
> put these in a group of rackmount cases.
> Buy a decent machine with a bunch of memory.
> Buy a couple of good SCSI cards.
> 
> Put these together with Linux (or OS of choice) and
> a couple of big slices. Bingo. For less than $20,000
> I just got 3.2TB max (probably would be less as
> I would want to make some hot spares and such). That
> gets me ~3yrs data. If I'm feeling crazy, I put together
> another one at the other store and let them mirror
> (safe from fire).
> 
> This wouldn't really need to be a high performance beast,
> as data would basically be dribbling in. But I guess with
> more busess and some striping it could be a decent performer.
> If there is a way to get some drives to sleep, then power
> consumption would drop dramatically. It seems that the
> same company also makes a IDE backplane which makes some
> sort of hot swapping availble. WD gives a 5 year life span
> to the drive, but by then I'm sure you could just buy the
> new 300GB drives and stick them in (what is that... 240TB,
> good lord).
> 
> For comparison Sun's A1000 gives 436GB for $22,220.00 or
> a nickel a MB compared to $20,000 for this system at
> 6/10 of a penny per MB
> 
> Am I on crack? It just seems wrong.  Do I have some order
> of magnitude wrong here?
> What do you guys think of this?
> --
>                 Jody Stephens -- (303)322-1965 x2608
>                       jodys at tatteredcover.com
>                      Tattered Cover Book Store
>                           1628 16th Street
>                          Denver, Co. 80202
>                        (303)322-1965 Offices
> (303)436-1070 LoDo Store         (303)629-1704 Office and LoDo Fax
> (303)322-7727 Cherry Creek Store (303)399-2279 Cherry Creek Fax
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