[geeks] SATA Cards

[John Francini]

On 2 Jul 2009, at 0:20, Phil Stracchino wrote:

> Sridhar Ayengar wrote:
>> Phil Stracchino wrote:
>>> At this point, it's "cheapest total cost", even the smallest new  
>>> drives
>>> on the market being an order of magnitude bigger than what the  
>>> machine
>>> needs.  But actually, it turns out my original assumption stands.   
>>> Hard
>>> disk storage has gotten insanely cheap ... IFF you can use SATA.   
>>> If you
>>> want a *new* (not reconditioned) SCSI disk, you're pretty much  
>>> fucked.
>>> The entire SCSI disk market, aside from a few major-vendor-branded
>>> pre-mounted server disks still priced at several dollars per  
>>> gigabyte,
>>> seems to be people reselling the same stock of multiply  
>>> reconditioned
>>> disks over and over.  It doesn't look like you can even buy  
>>> SATA-1.5GB
>>> disks new any more; everything new is SATA-3.0GB.
>>
>> Many of our drives at work these days are now SAS.  2.5" 10K RPM SAS.
>
> *nod*  babylon4 boots off a separate mirrored pair of 2.5" SATA disks.
> It's sorta frustrating to know that if I was working right now, I  
> could
> fill all twelve array slots in the machine with 500GB disks for a few
> hundred dollars, or with 1TB disks for not much more.
>
> I imagine when you're installing a large number of disks, the power
> savings of 2.5" disks are probably pretty significant.


Sridhar beat me to it to suggest SAS, since that does seem to be the  
successor to (p)SCSI.  However, like most things SCSI, it's more  
expensive.

Interestingly, the storage arrays we design at work (Dell|EqualLogic)  
all use SAS controllers to talk to the drives; SATA drives work, but  
only with a dongle on the drive sled to convert the dual-channel SAS  
signals to SATA.

To Phil's point:  I'm in the midst of cleaning up my (home) computer  
room/office; I may have one or two PCI SATA cards kicking around that  
I'd be willing to part with.  I'll have to check.

j