Good morning Andras, On 10/20/2015 11:52 PM, andras@xxxxxxxxxxxxxxxx wrote: > Phil, > > Thank you so much for the detailed explanation and your patience with > me! Sorry for not being more responsive - I don't have access to this > mail account from work. No worries. >> for x in /sys/block/*/device/timeout ; do echo 180 > $x ; done >> >> (Arrange for this to happen on every boot, and keep doing it manually >> until your boot scripts are fixed.) > > Yes, will do. In your links below it seems that you're half advocating > for using desktop drives in RAID arrays, half advocating against. From > what I can tell, it seems the recommendation might depend on the > use-case. If one doesn't care too much about instant performance in case > of errors, one might want to use desktop drivers (with the above fix). > If one wants reliable performance, one probably wants NAS drives. Did I > understand the basic trade-off correctly? Times change. At the time some of those were written, desktop drives with scterc support were still available, but default off. Those are ok in a raid if you have the appropriate smartctl command in your boot scripts. Long timeouts with non-scterc drives, in my opinion, create a user impression that things are broken, even if the drive is fine (UREs are natural and unavoidable in the life of a drive). Users are prone to drastic measures when they think something is broken. Also, *applications* might not wait that long for their read, either. So, I only recommend the long timeout solution when an array is already in trouble with such drives. > It seems that people also think that green drives are a bad idea in > RAIDs in general - mostly because the frequent parking of heads reduces > life-time. Is that a correct statement? I don't have enough experience with green drives to say. The few that I have (bought before I discovered the dropped scterc support) became part of my offsite backup rotation. > Yes sir! I will go through the steps and report back. One question: the > reason I shouldn't attempt to re-create the new 10-disk array is that it > would wipe out the 7->10 grow progress, so MD would think that it's a > fully grown 10-disk array, right? Right. Your three extra drives never really were incorporated into the array, so the data layout is still a 7-drive pattern. 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
