April 12, 201511 yr Hi, Yesterday, i decided to upgrade my parity drive from 4tb to 6tb. Parity sync started with an average speed of 20MB/sec and showed it would take 2 days 6 hours to complete. I just checked the webGui now and it shows 9MB/sec - see screenshot below Is this the normal speed i should expect during a 6TB parity sync? I just tried to post a system log and i got this error message: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 132075537 bytes) in /usr/local/emhttp/plugins/dynamix/include/DefaultPageLayout.php(275) : eval()'d code on line 14 Spec: Motherboard:Gigabyte Z77-DS3H CPU:i5-3470T RAM: Corsair Vengeance Low Profile 16GB (2x8GB) PSU - Corsair TX950W Sata Controller - 2 x Supermicro AOC-SASLP-MV8 8-Port SAS/SATA 3Gbs PCIe HDD: 1 parity, 18 data and 1 cache drive. 20 drives = 60TB Version:6.0-beta14b - The parity drive is connected directly to one of the motherboard's sata port - cat6 cable connection from unRaid server to gigabit switch - gigabit switch connected to router
April 12, 201511 yr No, that is WAY too slow => the sync should be at least ten times that fast, and probably faster (depends on what your other drives are). Are you showing any drive errors or sync errors?
April 12, 201511 yr Clearly you're having major issues with Disk #3 ... which is why it's running so slow. I suspect you need to either reseat the drive (if in a hot-swap chassis) or reseat the cables for the drive (if independently cabled). You probably inadvertently moved the drive a bit when you were installing the new parity drive or moving the old parity drive. I'd stop the parity sync; reseat drive #3; and then restart a new sync.
April 13, 201511 yr Author Thanks...I followed the steps above last night ( stop the parity sync, reseat drive #3 and restart a new sync) I checked the webgui earlier this morning and parity sync is still slow...here is the screenshot i grabbed.
April 13, 201511 yr Yes I unmounted disk4. Hopefully rebuild after parity sync What do you mean "rebuild"?
April 13, 201511 yr Yes I unmounted disk4. Hopefully rebuild after parity sync What do you mean "rebuild"? Clearly disk #4 is the old parity drive ... I'm sure he means he'll format it later.
April 13, 201511 yr Yes I unmounted disk4. Hopefully rebuild after parity sync What do you mean "rebuild"? Clearly disk #4 is the old parity drive ... I'm sure he means he'll format it and add it to the array. If he were adding it as disk18 then it would be clearer. But disk4 makes me wonder if he wasn't intending to rebuild a disk4 that was smaller than 4TB onto the old 4TB parity drive. Hope not.
April 13, 201511 yr Yes I unmounted disk4. Hopefully rebuild after parity sync What do you mean "rebuild"? Clearly disk #4 is the old parity drive ... I'm sure he means he'll format it and add it to the array. If he were adding it as disk18 then it would be clearer. But disk4 makes me wonder if he wasn't intending to rebuild a disk4 that was smaller than 4TB onto the old 4TB parity drive. Hope not. That was my fear also..after parity sync, no unRaid rebuild is going to be possible.
April 13, 201511 yr Yes I unmounted disk4. Hopefully rebuild after parity sync What do you mean "rebuild"? Clearly disk #4 is the old parity drive ... I'm sure he means he'll format it and add it to the array. If he were adding it as disk18 then it would be clearer. But disk4 makes me wonder if he wasn't intending to rebuild a disk4 that was smaller than 4TB onto the old 4TB parity drive. Hope not. Yes, I hope not too ... but it seems very unlikely that's the case, since he said at the beginning he was simply upgrading parity
April 13, 201511 yr Thanks...I followed the steps above last night ( stop the parity sync, reseat drive #3 and restart a new sync) I checked the webgui earlier this morning and parity sync is still slow It's still slower than it should be ... HOWEVER, (a) it's 3 times as fast as it was before; and (b) you're no longer getting all the read errors on disk #3 ==> so at least it's working well now. The slow speed, however, indicates something isn't working right. I can think of two possibilities ... #1 (Most likely) It's possible that one of your controllers isn't seated well in the PCIe slot. Your motherboard has one PCIe x16 slot and one PCIe x4 slot (both use x16 connectors). If one of the controllers isn't seated well and is only connecting at x1 speed, this would result in a significant bandwidth limitation, and would explain the slow speed you're still seeing. #2 The answer I gave to Brian's question above made me look more closely at your setup. While I think what I said is indeed what your plan is, it seems you've actually already assigned disk #4 to the array ... you just haven't formatted it yet. This shouldn't make any difference in the parity sync ... the unformatted contents are simply included in the parity calculations -- and clearly this is happening, since it's got the same level of writes as the other disks in the array, and no errors. But it's certainly possible that for some reason this is causing some additional overhead.
April 13, 201511 yr By the way, you clearly can't reseat a card while the system is on, so you have two choices ... (1) Wait for the sync to finish or (2) Abort the sync (again). Shut down the system and unplug and replug both of your controller cards. Then reboot and restart the sync. Just to be CERTAIN that #2 above isn't part of the issue, I'd either format drive #4 before you start the parity check; or do a New Config and leave that drive out of the configuration.
April 13, 201511 yr Author Opps looks like i messed up there... yes, i thought i could rebuild disk4 after parity sync but looks like i have lost the data. Some more info.. - I decided to upgrade from v5 to v6 so i could install some apps. More details here https://lime-technology.com/forum/index.php?topic=39157.msg364470#msg364470 - I got a 6tb to replace 4tb parity drive so i could install add old 4tb parity drive as a data drive - Just before i installed the 6tb i noticed disk 4 was red balled so i thought, it would be better to install the old parity on disk 4. Well looks like the last step was a bad idea… However, i still have the red balled 3tb sata, any chance i could add this as disk 19?
April 13, 201511 yr Ouch !! You for sure should have mentioned that "little tidbit" in your initial description of your problem !! So right now you should STOP your parity sync and do NOTHING ... more in a couple minutes ...
April 13, 201511 yr You can't add it to the array without unRAID clearing it, so that wouldn't work if you wanted to keep the data. A new config would let you keep its data intact but you would have to rebuild parity. Probably a better idea would be to just try to copy the data from it instead of adding it to the array. Maybe a SMART report of that drive would be useful. If you copy the data from it then you could preclear and add it to the array if you wanted. I wonder how you actually got to this point though. If you replaced disk4 then unRAID would have complained about a wrong disk. How did you get it to let you do a parity sync?
April 13, 201511 yr The correct approach would have been to use the Swap Disable procedure. unRAID would copy the old parity to the new parity drive and then rebuild the disabled disk onto the old parity drive. The drive was redballed due to a write failure. Probably a lot of the data can be recovered from it, but don't do anything without further instruction.
April 13, 201511 yr A couple thoughts r.e. what to do now ... 1. If you have good backups, I'd just go ahead and format #4, reseat your controller cards (as I already noted); and do the parity sync ... then copy the data you had on #3 to the array from your backups. 2. If you don't have backups, and you are CERTAIN that you've done NO writes to the array since you made the configuration changes (except for the writes to the new parity drive as part of the sync process), then you can still recover and install a replacement drive for the failed drive. You'll need a new 3TB or 4TB drive to do the rebuild. Just do EXACTLY the following: (a) Do a New Config, assigning the old 4TB parity drive as the parity drive and all of the data drives including the old failed 3TB drive, and check the "Parity is Good" (i.e. "Trust Parity" option). Start the array ... and if it starts a parity check immediately cancel it. (b) Stop the array, unassign disk #4 (assuming that's where you put the failed 3TB drive); then Start the array so the disk is shown as missing. Then Stop the array; assign the NEW 3 or 4 TB drive you want to rebuild the failed drive on to slot #4; and then Start the array and let it do the rebuild. © When the rebuild is done, THEN you can upgrade your parity drive to the new 6TB drive 3. If you HAVE done writes to the array, but don't have backups, then I'd just do as I suggested in #1 (i.e. go ahead and format #4, reseat your controller cards (as I already noted); and do the parity sync ==> and then I'd attach the old red-balled 3TB drive to a client PC, using the free Linux Reader utility [ http://www.diskinternals.com/linux-reader/ ] to read the disk ... and copy as much data as possible to your array from that disk. If the disk isn't readable, you could alternatively attach it to your UnRAID system (do NOT assign it to the array -- that will wipe the data), and use the Reiserfsck utility to attempt recovery of the data => but first see if you can simply read it on another system.
April 13, 201511 yr The correct approach would have been to use the Swap Disable procedure. Absolutely ... but I don't think there's any way to force that now. Had that been followed initially, this would have all been simple => UnRAID would have simply copied the old parity; rebuilt the failed drive on the old parity drive; and all would be well ... EXCEPT for the connection issue with drive #3 that was resolved by reseating the drive and/or cables; and possibly the controller seating issue that seems to be causing some bandwidth restrictions.
April 13, 201511 yr Author Thanks all for taking time to comment on this thread... so i decided to go with option 1. 1. If you have good backups, I'd just go ahead and format #4, reseat your controller cards (as I already noted); and do the parity sync ... then copy the data you had on #3 to the array from your backups. I also rebooted router and switch, replaced the ethernet cable between unraid server and switch, connected parity drive sata cable to sata3(noticed it was connected to the sata2 slot on the mb) Result = 27.2mb/sec I'll let the parity sync finish and copy the data from the 3tb sata to the array.
April 13, 201511 yr Author Thanks all for taking time to comment on this thread. ....so i decided to go with option 1. 1. If you have good backups, I'd just go ahead and format #4, reseat your controller cards (as I already noted); and do the parity sync ... then copy the data you had on #3 to the array from your backups. I also rebooted router and switch, replaced the ethernet cable between unraid server and switch, connected parity drive sata cable to sata3(noticed it was connected to the sata2 slot on the mb) Result = 26.9mb/sec :( I'll let the parity sync finish and copy the data from the 3tb sata to the array.
April 13, 201511 yr I also rebooted router and switch, replaced the ethernet cable between unraid server and switch, connected parity drive sata cable to sata3(noticed it was connected to the sata2 slot on the mb) Result = 26.9mb/sec :( The router and switch have nothing to do with the parity sync. And whether the parity drive is on a SATA-2 or SATA-3 port also doesn't matter => no rotating drive sustains speeds higher than SATA-2 can transfer. The speed you're seeing sure sounds like one of your controllers is only interfacing at PCIe x1 speed. If it's seated firmly, you may have a defective motherboard slot. There are a few things you can try to test this, but not until after the parity sync has completed.
April 13, 201511 yr Author Thanks Going forward, any suggestions on how i can improve performance\speed? I was thinking to do the following: - Replace motherboard with one with 2 x pcie x16. - Replace my current AAOC-SASLP-MV8 (3.0 Gigabits/sec) with AOC-SAS2LP-MV8(6.0 Gigabits/sec) I assume this would do the trick?
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