lovingHDTV Posted September 21, 2015 Share Posted September 21, 2015 I'm curious as to how this should work. I ran prelcear on all 3 off my 5TB drives. I then swapped out my parity drive, and waited the 12 hours to rebuild parity. Since the second largest drive in the system is 2TB, i though that once you got through that it would go faster, since there really is no parity to check and the drive was precleared. But no, it took the 12 hours. I then swapped out my one 1TB drive for another 5TB precleared drive, and it is has now rebuilt beyond where the drive was used. It still reports 11hour to go before the rebuild is done. It seems as if preclear didn't really help me get my drives put in any quicker. I thought that last time I did this it actually helped. I ran preclear using the latest script for the thread that the nice plugin for it. They all reported complete with a good smart report. david Quote Link to comment
Squid Posted September 21, 2015 Share Posted September 21, 2015 I'm curious as to how this should work. I ran prelcear on all 3 off my 5TB drives. I then swapped out my parity drive, and waited the 12 hours to rebuild parity. Since the second largest drive in the system is 2TB, i though that once you got through that it would go faster, since there really is no parity to check and the drive was precleared. But no, it took the 12 hours. It still has to write to the remainder of the drive (by emulating the other drives beyond 2TB). It was probably going as fast as it could write to the drive. I then swapped out my one 1TB drive for another 5TB precleared drive, and it is has now rebuilt beyond where the drive was used. It still reports 11hour to go before the rebuild is done. Same thing as above. In this case, its reading the parity drive and calculating what the value should be on the 5TB beyond 2TB. (In this case, zeros) It seems as if preclear didn't really help me get my drives put in any quicker. I thought that last time I did this it actually helped. Preclear doesn't speed anything up if you're rebuilding (swapping) a drive. What it does in this case is make sure that the drive is actually healthy enough to put into the array. If you were adding a new drive to the system, what preclear does is two fold: Verify the drive is healthy, and zero it out so that unRaid can add the additional capacity within a matter of minutes. If you add a drive without preclearing it, then unRaid itself has to clear the drive, and the array would wind up being completely unavailable during that process (12+ hours) Quote Link to comment
gfjardim Posted September 21, 2015 Share Posted September 21, 2015 I'm curious as to how this should work. I ran prelcear on all 3 off my 5TB drives. I then swapped out my parity drive, and waited the 12 hours to rebuild parity. Since the second largest drive in the system is 2TB, i though that once you got through that it would go faster, since there really is no parity to check and the drive was precleared. But no, it took the 12 hours. I then swapped out my one 1TB drive for another 5TB precleared drive, and it is has now rebuilt beyond where the drive was used. It still reports 11hour to go before the rebuild is done. It seems as if preclear didn't really help me get my drives put in any quicker. I thought that last time I did this it actually helped. I ran preclear using the latest script for the thread that the nice plugin for it. They all reported complete with a good smart report. david The precleared disk only cuts time if you expand the array, e.g., you had 12 disks in the array and you add a 13th precleared disk. All other tasks (disk replacement and parity disk replacement) need to write all disk again, so no time saved here. Even in those cases, it's recommended to run the prelear script, since it's a nice burn-in test against defective drives. Quote Link to comment
lovingHDTV Posted September 21, 2015 Author Share Posted September 21, 2015 thanks all. Previously I had always expanded my array. I'm now just upgrading drives because I don't want more drives. I'll wait 12 hours per drive david Quote Link to comment
lovingHDTV Posted September 21, 2015 Author Share Posted September 21, 2015 I take that back. 5 hours into it I'm not up to 1day 15 hours left. At this rate I will never complete the upgrade. It really slowed down after it passed the 785GB (from the previous disk), instead of 60MBps I'm down to 24MBps. Who know verifying zeros was so complicated. david Quote Link to comment
lovingHDTV Posted September 21, 2015 Author Share Posted September 21, 2015 Great dropped to 13MBps, never seen it this slow ever. I'm up to over 2 days for this rebuild. Ideas? david Quote Link to comment
dgaschk Posted September 21, 2015 Share Posted September 21, 2015 Post diagnostics. Tools->Diagnostics. Quote Link to comment
lovingHDTV Posted September 21, 2015 Author Share Posted September 21, 2015 Here it is. Pretty cool, I didn't know that existed. david tower-diagnostics-20150921-1617.zip Quote Link to comment
lovingHDTV Posted September 21, 2015 Author Share Posted September 21, 2015 Now that I'm past the 2TB part (where all my other drives end) it is running very fast. 175MBps, says it will complete in 5 hours. I guess I'm just surprised that the parity rebuild estimated 11 hours and it was right on. It never sped up and never slowed down. david Quote Link to comment
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