On 3/10/2011 1:01 PM, John R Pierce wrote:
> On 03/10/11 10:56 AM, Les Mikesell wrote:
>> How important is the card-level battery if you have a UPS and a scheme
>> to monitor it and do a graceful shutdown before it fails?
>
> how important is your data? if your system *never* crashes, and you're
> not running something like a database server dependent on committed
> writes, I'm sure you'd be fine.
>
> me, personally, I've had to recover from DC total UPS failures. I like
> to put redundant power supplies on alternate UPS's, but with datacenter
> sized UPS's thats often not an option.
Sure, UPS's fail, plugs get pulled, etc., but the cards and internal
batteries most likely have their own failure modes. Or the whole box
can fry at once. Did you have any way to tell if your battery-backed
saved any data as the disks lost power or did the filesystems just back
out the incomplete writes anyway?
--
Les Mikesell
lesmikesell at gmail.com