Re: Shared Storage?

WipeOut wrote:
> Nik Simpson wrote:
>> WipeOut wrote:
>>
>>> Hi,
>>>
>>> I am going to be setting up a couple of linux servers in the near
>>> future and these servers will have ever increasing storage needs..
>>>
>>> One server will be a web/file server and the other will be a mail
>>> server..
>>>
>>> I don't want to keep moving the data to bigger drives, I want to
>>> have the servers use a shared storage facility that runs RAID and
>>> that capacity can be increased as needed.. Preferably using ATA or
>>> SATA drives to keep the cost down..
>>>
>>> I have looked briefly at things like SAN's but these are far to
>>> expensive for our limited budget..
>>>
>>
>> What is your budget? You maybe ruling at FC attached storage (no
>> need for a switch) too quickly. A dual ported FC array with software
>> on each host to create a shared filesystem might be in your budget,
>> but it's hard to tell.
>
> I ruled out FC for a few reasons, I only saw SCSI drives and alone
> they are to expensive per GB compared to PATA/SATA, The FC HBA's are
> very steep as well probably costing as much as the whole server, and
> then there is the switch and the array..

You need to look a bit harder, there are a number of SATA/PATA storage
systems with FC interfaces on the market, take a look at www.nexsan.com for
an example. Also, if you only have two systems, then you don't need a
switch, both systems can be direct attached to the array. Yes, the FC HBAs
are still quite pricey, but overall a SATA based FC array and HBAs for two
servers isn't that bad, unless your budget is *very* limited.

Another possible solution that would get rid of the FC costs is iSCSI, again
there are a number of iSCSI arrays that use SATA/PATA drives.


>
> I think NAS on a dedicated GigE netowrk and if possible a dedicated
> link between each server and the NAS is probably the way to go..
>
> For the NAS its self I will probably just use a Linux server and an 8
> or 12 channel SATA RAID controller with 3 or 4 drives to start and
> then add on as needed using LVM for the storage management.. I don't
> think I will be able to do it much cheaper than that.. :)
>

My guess from the configuration you've described is that the I/O demands for
the two systems are not equal, I'd bet that the mailserver needs I/O
performance much more than the webserver, in which case, why not direct
attach the storage to the mail server and share some of its capacity with
the webserver?

As I said previously, giving us an idea of your budget, i.e. how much you
are prepared/able to spend would help in suggesting possible solutions.
-- 
Nik Simpson