On 05/24/2011 02:01 PM, John R Pierce wrote:
On 05/24/11 10:32 AM, Gordon Messmer wrote:
On 05/24/2011 09:57 AM, John R Pierce wrote:
also you want SSD that has a supercap on its internal cache so pending
writes aren't lost in a power failure scenario.
You know, I've asked people about that in the past since the whole block
read/erase/write cycle seems like a risk in the event of power loss, but
never got any satisfactory answer. What manufacturers/models offer that
feature? Are most drives with caps clearly labeled?
I just looked at OCZ's marketing fluff--err--webpile and it appears the
Vertex EX and PRO drives advertise that they have a supercapacitor. the
others I sampled didn't.
http://www.ocztechnology.com/ocz-vertex-2-pro-series-sata-ii-2-5-ssd.html
my superficial scan of Intel's webpile didn't turn up any reference to
them on the x25-e or 510 drives. ah, the intel 320 series has power
failure protection which presumably means something like a supercap to
supply sufficient power to complete any pending write cycles..
There's an article on anandtech detailing datalosses on many SSDs on
power failure scenarios.
(and, please folks, UPS's are great, but they fail too, you can't rely
on them for data protection).
Thats why you have servers with redundant power supplies with each power supply
plugged into a separate ups.
--
Stephen Clark
*NetWolves*
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.cl...@netwolves.com
http://www.netwolves.com
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