On 2/5/09 4:40 AM, "Matt Burke" <mattbli...@icritical.com> wrote:

Are there any reasonable choices for bigger (3+ shelf) direct-connected
RAID10 arrays, or are hideously expensive SANs the only option? I've
checked out the latest Areca controllers, but the manual available on
their website states there's a limitation of 32 disks in an array...

What I'm using currently:
Adaptec / Areca cards + Promise V-Trac J610S  (for 3.5" drives, if total 
storage is your concern).  Multiple cards if necessary and you want dual-path 
to each drive.
http://www.promise.com/product/product_detail_eng.asp?segment=undefined&product_id=190
http://www.promise.com/product/product_detail_eng.asp?segment=undefined&product_id=189

Using two of the former with two Adaptec cards (Software raid 0 on top of them) 
with great success.
There's 2.5" drive ones too from other manufacturers ... The Promise one here 
scared me at first until I got confirmation from several experts actually using 
them in place of Dell MD1000 and HP SAS expander boxes because of higher device 
compatibility (Dells only works with PERC, etc) and reasonable cost.
You probably don't want a single array with more than 32 drives anyway, its 
almost always better to start carving out chunks and using software raid 0 or 1 
on top of that for various reasons. I wouldn't put more than 16 drives in one 
array on any of these RAID cards, they're just not optimized for really big 
arrays and tend to fade between 6 to 16 in one array, depending on the quality.

High quality SAS expander boxes compatible with good, non-proprietary RAID 
cards are not those from T1 vendors.  The Promise above has a large 
compatibility list, since it uses 'standard' controller chips, etc.  There are 
several others.  See the Adaptec and Areca SAS expander compatibility lists.   
Dual redundant path to drives is nice.

You can do direct-attached storage to 100+ drives or more if you want.  The 
price and manageability cost go up a lot if it gets too big however.  Having 
global hot spare drives is critical.  Not that the cost of using SAN's and such 
is low...  SAS expanders have made DAS with large arrays very accessible though.
Sun has some nice solutions here too, but like all T1 vendors the compatibility 
lists are smaller.  Their RAID card they sell is an OEM'd Adaptec and performs 
nicely.  The Sun 4150 with a direct-attached SAS storage makes a pretty good DB 
server.  And yes, you can run Linux on it or Solaris or OpenSolaris or Windows 
or some BSD variants.

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