October 13, 201213 yr Hi Everyone, I've used the preclear script (Without any switches, version 1.1) on a new disk, and it finished successfully. After that, I stopped my array, assigned the new disk. I got the following screen (this is after I checked the box and clicked start): Right now, the webGui is stuck on this message: Spinning up all drives...clearing disk4... ...clearing 1% complete I would mind if unRaid performed this "second' clear (although I don't think this is expected behavior). However, my real problem is that the array is offline and I can't access my files. Syslog is here: http://pastebin.com/7YYrKGh6 Any help will be appreciated, Thanks, Samcon
October 13, 201213 yr Author Did you use 1.1 or 1.13 ? Was it a <=2Tb or >2Tb disk ? I used 1.1, with a 3TB disk. Unfortunately, I thought that that version support > 2TB drivers, but I guess it doesn't. Since the drive was already precleared, can I use the script to just put the "signature" to indicate the drive is cleared? If possible, is this a good idea? Thanks!
October 13, 201213 yr If you ask me, I would preclear it with 1.13 again just to be sure. If you don't you still have to do a parity check (with correct) to verify it was indeed pre-cleared and this would take more time than pre-clearing it again. Also during the parity check your array will not be protected. So just preclear it again...
October 14, 201213 yr If you ask me, I would preclear it with 1.13 again just to be sure. If you don't you still have to do a parity check (with correct) to verify it was indeed pre-cleared and this would take more time than pre-clearing it again. Also during the parity check your array will not be protected. So just preclear it again... This is incorrect. pre-clear will take much longer than a parity check and the array is protected during a parity check.
October 14, 201213 yr If you ask me, I would preclear it with 1.13 again just to be sure. If you don't you still have to do a parity check (with correct) to verify it was indeed pre-cleared and this would take more time than pre-clearing it again. Also during the parity check your array will not be protected. So just preclear it again... This is incorrect. pre-clear will take much longer than a parity check and the array is protected during a parity check. During a normal parity check the array is protected, but in this case a drive has been added which might not be zeroed but as the signature is available unraid trusted the disk to be zeros.... If the disk did not contain zeros and a disk fails it will be reconstructed using wrong parity data (or wrong disk data, just how you look at it). If the parity checks finds no corrections (and thus the new disk was indeed 100% zeroed) then the array was protected during the check, if the parity check finds corrections the array was not protected during the check. Regarding the speed issue. If you preclear it again using 1 pass and only the write pass this could be faster than a parity check which reads all disks. In my case with a 4Tb parity disk and new 3Tb data disks a write-only preclear is always faster dan a full parity check. Writing occurs at 100Mb/s initially whereas my parity checks never go beyond 50Mb/s. Another point to make, your previous pre-clear might have written only 2Tb, and thus the 'stress-test' component of pre-clearing has not been run on the complete disk, so another reason to do a full (read-write-read) preclear on this new disk. A full preclear will be slower than the parity check.
October 14, 201213 yr UnRAID is clearing the drive so parity is not effected at all. Why run a a write only pre-clear when the disk has just been cleared? Right now, the webGui is stuck on this message: Spinning up all drives...clearing disk4... ...clearing 1% complete A parity check after adding a new drive is a good idea.
October 14, 201213 yr UnRAID is clearing the drive so parity is not effected at all. Why run a a write only pre-clear when the disk has just been cleared? Because he stated he cleared a 3Tb disk with preclear 1.1. unraid did not recognize it as precleared as well, so in fact it wasn't precleared in the sense that you would have a guarantee it was 100% zero'ed
October 14, 201213 yr UnRAID is clearing the drive so parity is not effected at all. Why run a a write only pre-clear when the disk has just been cleared? Because he stated he cleared a 3Tb disk with preclear 1.1. unraid did not recognize it as precleared as well, so in fact it wasn't precleared in the sense that you would have a guarantee it was 100% zero'ed It makes no difference what pre-clear 1.1 did to the disk. unRAID did not accept the disk as cleared and is clearing the disk itself. This message indicates that the disk is being zeroed by unRAID: Spinning up all drives...clearing disk4... ...clearing 1% complete The array will become responsive again once unRAID has finished clearing the dives. At no time is parity effected by clearing the disk. A parity check after adding a new drive is desired in any case.
October 14, 201213 yr It makes no difference what pre-clear 1.1 did to the disk. unRAID did not accept the disk as cleared and is clearing the disk itself. This message indicates that the disk is being zeroed by unRAID: Spinning up all drives...clearing disk4... ...clearing 1% complete My suggestions were reactions on samcons question : "Since the drive was already precleared, can I use the script to just put the "signature" to indicate the drive is cleared? If possible, is this a good idea?"
October 14, 201213 yr It makes no difference what pre-clear 1.1 did to the disk. unRAID did not accept the disk as cleared and is clearing the disk itself. This message indicates that the disk is being zeroed by unRAID: Spinning up all drives...clearing disk4... ...clearing 1% complete My suggestions were reactions on samcons question : "Since the drive was already precleared, can I use the script to just put the "signature" to indicate the drive is cleared? If possible, is this a good idea?" There is no such function in pre-clear. The disk has been read and written completely by pre-clear. It does not have the correct partition or signature. unRAID is partitioning and clearing the disk. Check the SMART report for pending sectors or failed values. If SMART is ok then use the disk. At no time was parity out of sync or the array unprotected. Running a write-only pre-clear would simply repeat the procedure that unRAID has just completed without any value added.
October 14, 201213 yr You could have stopped the preclear and initialized the array and started it again. It would do a parity sync but the parity would actually still be OK since the disk is cleared. I'm pretty sure that version of the script did clear the drive, it just doesn't do the post work of setting it as cleared and ready to use. There is an option in the script to clear only. It would cut the time down to about 1/3 compared to running the full 3 passes.
October 16, 201213 yr Author There is an option in the script to clear only. It would cut the time down to about 1/3 compared to running the full 3 passes. This is what I did eventually, and indeed it was faster. Thanks everybody!
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