November 30, 20169 yr Greetings! I have been experiencing extremely slow writes and reads from my unRAID system, I believe after completing a parity swap. I had to replace a failing data disk, and in the process moved to a larger parity drive (from 2TB to 3TB). Ever since, it seems that when a file is being written to the array, write speeds are slow, and reads are also affected (i.e. playing videos via Kodi results in pausing and stopping). As of this morning, a mover job has been trying to move approximately 80GB from cache to the array. From looking at the syslog, it looks like some writes take a few minutes, while others take 30+ minutes, for files that should be similar in size. I've attached a diagnostics archive from early this morning. I am running unRAID 6.1.4. Any help is appreciated. I cannot figure out anything other than the array writes being the issue, but no obvious cause. Thanks, Dave UPDATE: The parity drive ended up being a shucked WD Green sold as new by a 3rd-party Amazon seller. After replacing it with a new drive, I have not experienced any more issues. Thanks johnnie.black for the support! tower-diagnostics-20161129-0514.zip
November 30, 20169 yr Community Expert There was a kernel oops, you should reboot and see if performance goes back to normal. Hopefully this was a one time thing but if it happens again you'll need to investigate it further.
December 1, 20169 yr Author I'll go for a reboot tonight, now that a pre-clear is complete. Thanks, Dave
December 1, 20169 yr Author I rebooted the server this morning, and was able to replicate the issues again. I copied a ~700MB file from my cache drive to the array, which took approximately 30 minutes. I did this on the server, with mc, so this is not a network issue. During this copy, I had a video playing on a remote Kodi system, which again suffered from stuttering and buffering. I'm attaching logs from during and after the transfer, in case they may show something between the two. Thanks! Dave tower-diagnostics-20161201-1150_AfterXfer.zip tower-diagnostics-20161201-1126_DuringXfer.zip
December 1, 20169 yr Community Expert I'm not seeing anything out of the ordinary, did you try copying to a different disk? Is the parity check speed normal? P.S.: you do have a disk with a pending sector, not related to this issue but worth checking. Device Model: WDC WD20EZRX-00D8PB0 Serial Number: WD-WCC4MPTAE2H7 5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 1 196 Reallocated_Event_Count 0x0032 199 199 000 Old_age Always - 1 197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 1
December 1, 20169 yr Author Thanks for the reply. For the copies, I'm going from a directory in /mnt/cache to a directory in /mnt/user. Would it be wise to try to copy direct to each disk (/mnt/diskN)? I will kick off a parity check. To be honest, I can't recall what "normal" speed would be for my system, so I can report back with the results. Thanks for the note on the drive. I have a precleared drive ready to go. Dave
December 1, 20169 yr Community Expert For the copies, I'm going from a directory in /mnt/cache to a directory in /mnt/user. Would it be wise to try to copy direct to each disk (/mnt/diskN)? Yes, try 2 different disks using /mnt/diskX
December 3, 20169 yr Author Interestingly, now that I have done a parity check, I cannot recreate the issue. I've tried copying files to all disks discretely, as well as to the array, and I am not seeing the issue. I will test some more tomorrow. Thanks for all the help. Dave
December 3, 20169 yr Author This morning I discovered that my parity drive is now showing 31,000+ errors in the Main WebUI. So, my uneducated guess is my new parity drive may be failing/failed? I found my syslog is full of: Tower kernel: md: disk0 read error, sector=3641072456 Oh, and I now see SMART for the disk shows: 197 Current pending sector 0x0032 200 200 000 Old age Always - 26 198 Offline uncorrectable 0x0030 200 200 000 Old age Offline - 26 Can I just get a confirmation that all I need to do is remove and replace the parity drive, and the rebuild will be automatic? I have a pre-cleared drive ready to go already. Is this just a matter of changing the drive assignment through the WebUI? Thanks, Dave tower-diagnostics-20161203-0909.zip
December 3, 20169 yr Community Expert Can I just get a confirmation that all I need to do is remove and replace the parity drive, and the rebuild will be automatic? I have a pre-cleared drive ready to go already. Is this just a matter of changing the drive assignment through the WebUI? Yes.
Archived
This topic is now archived and is closed to further replies.