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Hot-swap drives vs. NHS: physical difference?

Last response: in Storage
May 23, 2007 11:30:05 PM

I was surprised to realize i didn't know this today :D . I'm putting together a server and my boss "doesn't want the expense of hot-swap drives." I'm looking at parts listings of SATA drives, and none of them say that they're hot-swappable or not. The cases, of course, have h-s bays or they don't, but I think i'd always assumed there was a difference in the physical drive itself. Is there?? Can any off the shelf SATA drive be installed into a hot-swap bay and used thusly? Or are there h-s drives that i need?

The quote i originally received from a vendor with an insane price for a couple of 500GB SATAs was explained as "well, those hot swap drives cost quite a bit." Um... i went to look this up and i am not so sure about that explanation now. :)  thanks in advance!
May 24, 2007 2:37:59 AM

For SATA, there is no difference. Hot swap capability is a function of the enclosure, controller, and driver. The drive has nothing to do with it. So your vendor was completely blowing smoke. Find another vendor.

Now SCSI is a different matter. Normal SCSI drives have a 68-pin interface connector, a 4-pin Molex power connector, and jumpers for setting termination and SCSI ID. SCSI drives meant for hot-swap purposes use an 80-pin SCA connector, which combines all of those functions onto one connector. SCA SCSI drives can cost a few dollars more than normal SCSI drives, but we're talking < 5 % difference in price. SCSI drives are expensive to begin with because of their speed, enterprise-level reliability, and tuning for server operations.
May 24, 2007 12:24:34 PM

Thank you. I will indeed be finding a new vendor.
June 21, 2007 5:39:35 AM

It really depends on the server you have and what the hot swap bays are.

If your server only has hotswap bays then you need hotswap drives.

On most HP servers with SATA hotswap bays the Hotswap SATA drives are normal SATA drives mounted into a Hotswap frame. the Hotswap frame is similar in design to a HS SCSI disk - there is one connector (instead of normal 2 cables for normal drive).

From my experience of building many types of servers the hotswap drives (either SCSI or SATA) are much more expensive than normal drives. 50-70% more expensive - these are for name brand drives such as HP or Dell branded drives.