CPU & RAM in a storage box

[Etzion Bar-Noy]

This is a joke, right? You want someone to host your system, which, by
design, will not be rack-mountable, and would be large, due to the amount of
disks you are to place there. It is possible, but extremely expensive to
host a non-1-U server nowadays. Who would "give" it to you?

An industrial-grade, 2U system could host, today, about 6 3.5" SATA disks. A
3 U can do much more, with up to 12-14 disks, depending on the system.

And RAM is extremely important. Since you will not invest in an
industial-class RAID controller (3ware, LSI-Logic, Adaptec, Intel, etc)
which will cost several hundreds of dollars, as I see it, you would want to
compensate for the high write latency with a large amount of RAM and fully
buffered writes (not secure, but good enough). Especially with 7200RPM SATA
drives with low seek speed.
NFS shares, in "async" mode would give great performance, provided you give
the system enough RAM. Then your RAM will actually become the disk write
cache.

Ez

2010/9/9 Hetz Ben Hamo <hetzbh at gmail.com>

> Hi,
>
> 2010/9/9 geoffrey mendelson <geoffreymendelson at gmail.com>
>
>
>> On Sep 9, 2010, at 6:35 PM, Hetz Ben Hamo wrote:
>>
>>
>>> I'm planning to add some big storage solution to my VPS business. I did
>>> some checking and calculated the costs, and figured out that if I want to
>>> have a decent 12TB solution NAS box, it would be best if I would roll my
>>> own. (12 TB before all the RAID stuff, after that it would lot less). All
>>> other solutions are very expensive (example: IBM EXP 3000 costs here 6K nis
>>> without a single hard disk).
>>>
>>>
>> The question you should be asking yourself, IMHO, is what can I buy that
>> will be as reliable as a commerical, "industrial grade" server?
>
>
> Not looking for industrial grade one.
>
>>
>>  I'm planning to use hardware based RAID card, minimal Linux distribution
>>> and have some offers like iSCSI, NFS, CIFS - the usual suspects.
>>>
>>> My question is: since I'll use hardware RAID card, which processor and
>>> how much RAM should I put in such a machine? Xeon is overkill IIRC.
>>>
>>
>> For example, a system which costs under 900 NIS would do the job. You can
>> get them from Ivory or KSP. They have a dual core ATOM processor,
>> one PCI slot and one DDR2 memory slot. The power supply is not very big,
>> but it will power a bunch of 5400 rpm "green" disks.
>>
>
>
> This storage will be mainly used for backups. If someone wants to do a
> colocation to my rack, I want to give him a bonus, something that you can't
> find today with my competitors: I want to give him 50-100GB for storage.
> You'll get an NFS/CIFS/iSCSI and you mount it to your machine and use it for
> your backup/rsync/whatever. By comparison, when you colocate a server to
> Netvision's farm, you get ... 5GB backup space.. yippee..
>
>
>> How well will it work? How long will it last? Will it be fast enough?
>>
>
> "Fast" doesn't matter much when you're doing backups or storing some
> temporary stuff, does it really matter when it take 20 seconds instead of 10
> when you're doing rsync? I don't think so..
>
>
>> And the "killer" question, how much will it cost to replace, in the value
>> of downtime, your time to replace it, bad will among your customers, etc?
>>
>
> Really depends. I'm not planning to fully use all the disks, some will be
> disconnected or out of the RAID, perhaps I'll put a redundant PSU.
>
> Hetz
>
>
>> Geoff.
>>
>> --
>> Geoffrey S. Mendelson,  N3OWJ/4X1GM
>> To help restaurants, as part of the "stimulus package", everyone must
>> order dessert. As part of the socialized health plan, you are forbidden to
>> eat it. :-)
>>
>>
>>
>>
>>
>>
>>
>>
>
> --
> my blog (hebrew): http://benhamo.org
> Skype: heunique
> MSN: hetz-blog at benhamo.org
>
> _______________________________________________
> Linux-il mailing list
> Linux-il at cs.huji.ac.il
> http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.cs.huji.ac.il/pipermail/linux-il/attachments/20100909/133b0f5e/attachment.html>