Scott Laird wrote: > Today? Low-power SSDs are probably less reliable than low-power hard > drives, although they're too new to really know for certain. Given > the number of problems that vendors have had getting acceptable write > speeds, I'd be really amazed if they've done any real work on > long-term reliability yet.
Eh? Flash has been around for well over 25 years and the technology is well understood. Trivia: Sun has been shipping flash memory for nearly its entire history. What hasn't happened until relatively recently is that the vendors married high density flash with a decent controller which expects and manages failures -- like the disk drive guys did 20 years ago. It occurs to me that you might be too young to remember that format(1m) was the tool used to do media analysis and map bad sectors before those smarts were moved onto the disk ? ;-) Why, we used to have to regularly scan the media, reserve spare cylinders, and map out bad sectors in the snow, walking uphill, in our bare feet because shoes hadn't been invented yet... ;-) > Going forward, SSDs will almost certainly > be more reliable, as long as you have something SMART-ish watching the > number of worn-out SSD cells and recommending preemptive replacement > of worn-out drives every few years. That should be a slow, > predictable process, unlike most HD failures. > I think you will find that failures can still be catastrophic. But from a typical reliability analysis, the SSDs will be more reliable than HDDs. The enterprise SSDs have DRAM front-ends and plenty of spare cells to accommodate expected enterprise use. FWIW, I expect an MTBF of 3-4M hours for enterprise SSDs as compared to 1.6M hours for a top-tier enterprise HDD. More worrying is the relative newness of the firmware... but software reliability is a whole different ballgame. Rumor was that STEC won one of the Apple contracts http://webfeet.sp360hosting.com/Lists/Research%20News/DispForm.aspx?ID=32 STEC also supplies Sun and EMC. But the competition is really heating up with Intel and Samsung having made several recent announcements. We do live in interesting times :-) -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
