John R Pierce wrote:
>> Say, I had 4 devices with 500 GB drives exported using iSCSI. If a
>> single larger server
>> took those four iSCSI export drives, and created one md RAID 5 device,
>> could a single
>> server be turned off, and just degrade the array until it was either
>> replaced entirely
>> or brought back online?
>>
>
>
> how long would it take to replicate and rebuild a volume across the LAN
> via iscsi? if each of those slices was 500GB, you'd be reading 3 x
> 500GB and writing 500GB before the drive was resynched. note, a single
> drive on each storage controller in this scenario won't even achieve
> 1gigE speeds.
I'd think raid1 or 1+0 would be a better choice - these continue at full
speed with a missing member. You can continue to run while the raid
rebuilds, although if the drive is very busy you end up with the rebuild
fighting for head position and slowing things down.
--
Les Mikesell
lesmikesell at gmail.com