Re: RAID 5 3-drive array failed 2 disks at once - can anything be saved?

[Phil Turmel <philip@turmel.org>]

Hi Robert,

On 09/15/2013 04:42 PM, Robert Schultz wrote:
> Phil:
> 
> Thank you for the information. This is my backup machine. Up to this
> point I wasn't concerned about having a second copy of this machine, but
> I have a tendency to decommission a computer and leave the backups on by
> backuppc for archive purposes. I probably don't really, really need
> anything on this PC. That said I'm am very paranoid that I will have
> some other failure before I can resolve this :-(
> 
> I hadn't read anything about timing in disks in RAID - I'll have to go
> do some research. I see WD has their RED series that appears to be
> directed to this market.

Please do read the archives on the topic.  You won't regret it.

And yes, the WD REDs power up with SCTERC set properly.  I bought four
of these for my new media server.

> Here is the information requested. Please let me know if this changes
> anything in your instructions. I'll hold off until you confirm.

One modest change.  Two of your drives *do* support SCTERC, they just
have to have it enabled on every powerup:

> SCT Error Recovery Control:
>            Read: Disabled
>           Write: Disabled

For those two drives, your boot sequence should have:

smartctl -l scterc,70,70 /dev/sdX

For the other, you still need:

echo 180 >/sys/block/sdX/device/timeout

Otherwise, my recommendations stand.

Phil