Hi Hans, On 11/04/2013 03:07 PM, Hans Kraus wrote: > Hi, > > I put all my replaced and so on HDs in one machine to serve > backup duties, with backuppc. > > I assembled four raid0, each consiting of a 3 + 1 TB couple or > 2 + 2 TB couple. Some of these support scterc, some do not. I've > put the following in rc.local (by the way, the system is running > Debian): > cd /dev > for x in sd[a-z]; do > /bin/echo $x > "---------------------------------------------------------------------------" > > /usr/sbin/smartctl -s on -o on -S on /dev/$x || echo > "/usr/sbin/smartctl -s on -o on -S on /dev/$x failed." > /usr/sbin/smartctl -l scterc,70,70 /dev/$x || echo 180 >>/sys/block/$x/device/timeout || echo "/sys/block/$x/device/timeout not > available" > /usr/sbin/smartctl -t offline /dev/$x || echo "/usr/sbin/smartctl -t > offline /dev/$x failed" > /bin/echo > "-------------------------------------------------------------------------------" Good. > > done > > Afterwards, these four raid0 are the members of a raid5. The idea > behind this is to be able to replace the raid0 with single 4 TB drives. > Now comes my question: Do I need to care for timeouts of the raid0, and > if so, how do I do that? The following doesn't work: > for x in md??; do > /bin/echo $x > "--------------------------------------------------------------------------" > > echo 180 >/sys/block/$x/device/timeout || echo > "/sys/block/$x/device/timeout not available" > /bin/echo > "-------------------------------------------------------------------------------" > > done No. The timeouts only matter on the physical devices. MD doesn't have a timeout as it isn't a physical driver. What you have appears to be correct. Make sure you also have a "check" scrub in a cron job for everything greater than raid0. (Interval can vary--I use weekly.) And follow up on the cron job with a report of all mismatch-cnt values. For large capacities with consumer drives (~8TB or more, IMHO), you should seriously consider raid6. The probability of an unrecoverable read error interrupting a raid5 rebuild after a drive failure is shockingly high. HTH, Phil -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
