On 24 Jul 2014, at 10:00, Craig Sanders <cas@taz.net.au> wrote:
On Thu, Jul 24, 2014 at 09:45:45AM +1000, hannah commodore wrote:
I've inherited a system which has an Adaptec 2420SA RAID controller and 4x SSDs running in RAID6.
given that thet 2420SA doesn't do RAID6 natively, i guess you must be using mdadm linux software raid...
It does support RAID6, as well as 5EE, 10,50, 60 etc
if the motherboard has four spare SATA ports, have you tried plugging the SSDs directly into the m/b? i.e. i suspect that the problem is more likely with the adaptec card than with either the SSDs or the software raid.
I've tested this disks individually when they were kicked out of the array, and always seem fine. I've only seen 1 actually failed disk in almost a year of this array running. On 24 Jul 2014, at 11:29, Trent W. Buck <trentbuck@gmail.com> wrote:
Are you confident the disks are the problem? Since this is hardware RAID, you should have a spare RAID card. Swap that in, and see if the problem goes away. If it does, RMA the original card.
I'm not confident, no. I do have a replacement 2420SA I will try out. The write-cache battery also reports as Failed recently, so I'm thinking more and more it's the controller than anything else. On 24 Jul 2014, at 12:07, Russell Coker <russell@coker.com.au> wrote:
This could be related to TRIM. If you have it enabled it can cause significant delays and if you don't then eventually the SSD will need to clear erase blocks and cause delays for random writes.
Thanks. I'll have to see about how to change the TRIM settings on these Plextor drives. They don't show up as individual disks to the OS, but just the single logical volume