March 12, 201115 yr Author You can also try one of these commands. They will clear the MBR which will allow unRAID to align the disk (using the 4k aligned setting) when you install it. preclear_disk.sh -z /dev/sdX or dd if=/dev/zero count=8 of=/dev/sdX Just use the correct device in place of sdX for this drive you are working on. Having a disk properly pre-cleared really does not matter for the parity since the parity must be rebuilt. The preclear was just a burn-in of the disk. A properly precleared disk only matters when you are adding a data drive to an existing array. The preclear prevents the array from being unaccessable while unRAID clears the disk. In all other cases, you are just using the preclear for disk burn-in. Peter I get the same error with preclear_disk -z /dev/sdX. My guess is this is because it's on a usb/sata dock...but the preclear worked this way. Oh...or is it because I did the preclear with an old version, switched to the new version, and am trying to preclear with a switch now? Just guessing. CD
March 12, 201115 yr Author Attach the drive to a MB SATA port. Then it should work. To do that, I'll have to take the array offline (out of slots). But I guess I can do that...run this last preclear step, then start the swap process. CD
March 12, 201115 yr Author Crap, I think I messed up. I stopped the array, took the old parity drive out...put my new 2T in. I was thinking it would just show the array offline...which was fine...and it would show the new drive not in the array. I would then run the preclear -C 64...or one of the other switches for 4k alignment...and then I remembered I hadn't unassigned the parity drive before I removed it. So I thought, after the last preclear, I'd put the old parity back in, unassign, swap out, and in with the new parity. However, my array now says "upgrading parity". What should I do? QUICK CD
March 12, 201115 yr Click on the "parity" on the main screen. If it shows unaligned then do the following. Stop the array. Go to the devices tab an unassign the drive. Run the command - dd if=/dev/zero count=8 of=/dev/sdX Assign the drive again. Go to the main page and hit start. Peter
March 12, 201115 yr Author Click on the "parity" on the main screen. If it shows unaligned then do the following. Stop the array. Go to the devices tab an unassign the drive. Run the command - dd if=/dev/zero count=8 of=/dev/sdX Assign the drive again. Go to the main page and hit start. Peter Thanks again Peter! The parity showed unaligned. There was no option to stop the array available (or that's where I would have started)...but it would let me unassign the parity drive, so I guess it was never "active". OK...so now it says parity missing. I don't need to get the old parity in there at all? Just run this - dd if=/dev/zero count=8 of=/dev/sdX command, reassign the new parity, and let it rebuild? CD
March 12, 201115 yr Author OK... - dd if=/dev/zero count=8 of=/dev/sdx didn't work; said command not found (I wasn't sure whether to run this out of /boot...like a preclear...or what, so I tried it both ways and same result). But I was able to get the -C 64 switch to work this time. Ran super quick, but it said it saw the previous preclear, and was now aligned to start at sector 64. Should I assign it back to the parity slot, and check the alignment? EDIT- all looks good; now says 4k-aligned...and it's back to "rebuilding parity". Let it roll? CD
March 12, 201115 yr Author OK...it didn't seem as if I had much choice, other than to let the system rebuild parity; the start array button is ghosted out. But if I check "I'm sure I want to do this", I have the option to "start". Is that what I should do...or am I just sitting, waiting on this "upgrading parity"? CD
March 12, 201115 yr Author While I'm waiting on some of the other answers, let me ask this more general question...that'll help me understand unRAID better. For data drives, you need to unassign and re-assign new or replacement drives...so the array knows how to rebuild? But for parity, none of that is necessary...because it's simply going to rebuild off your data anyway? So...as has already been mentioned; the preclear is just stretching the drive before putting it into service...and the -C 64 switch is because of the advanced format 4k-alignment of the 2T EARS? So can I just assign my new parity drive, select "I'm sure I want to do this", and start to rebuild? CD
March 12, 201115 yr Yes. Start and your off. You can use the array normally while parity is building; although it will be slower, it should be able to serve video streams.
March 12, 201115 yr You usually don't need to unassign and re-assign the drives when you are swapping one. You shutdown and make the swap. unRAID assigns the new drive to the missing drive spot, assuming the new drive is a replacement for the missing one. This applies to both data and parity drives. You always have to click the "are you sure" box and then hit start before anything actually happens. Peter
March 13, 201115 yr Author Guys, I think I'm in the clear at this point. Thanks so much for all the help. One last question I guess, before I mark this sucker solved; I now want to put my old parity in the array. It's a 1.5 EARS. So I guess first, run a preclear, and then just swap out drives, and second...does it need a 4k-alignment or no? CD
March 13, 201115 yr Author OK, I'm getting this error again when I try to run preclear...just a "regular" preclear, on my old parity drive smartctl is unable to run on /dev/xxx with the -d ata option smartctl: device read identity failed <not an ATA/ATAPI device> A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.$ Remember, my slots are full, so this is with the drive in a usb/sata dock. I precleared the new 2T parity this way...but that was with the old preclear script. Is there somethng about this new preclear, that would make it not like a drive in a usb/sata dock? It's slow as sh*t anyway, so I'm happy to run it off the board. So...stop the array, swap out old drive, put in this replacement...and just run the preclear, before I assign it into the array? CD
March 13, 201115 yr It needs to be 4k-aligned without the jumper and needs to be unaligned with the jumper. If you are going to replace an existing drive and connect it to the motherboard then just set the proper alignment on the options page and start the array and let unRAID clear it. I'm guessing you never installed the jumper and if so you can use the 4k aligned setting. There is no real advantage to having the array offline while you use the preclear. I only say this because you have been using that drive so it really does not need to be burned-in. Otherwise. you can run the newest preclear script with the -n switch. This will skip the pre-reading and post-reading steps and only write zero's to the disk. I only say this because that disk has been used by you for a while and has proven it won't prematurely die. This should make the preclear take about 1/3 the time. You would also use the -A switch to ensure the drive is 4k aligned if you did not install a jumper. If you did install a jumper, then use the -a switch to make sure you do not 4k align the drive. Peter
March 13, 201115 yr OK, I'm getting this error again when I try to run preclear...just a "regular" preclear, on my old parity drive smartctl is unable to run on /dev/xxx with the -d ata option smartctl: device read identity failed <not an ATA/ATAPI device> A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.$ Remember, my slots are full, so this is with the drive in a usb/sata dock. I precleared the new 2T parity this way...but that was with the old preclear script. Is there somethng about this new preclear, that would make it not like a drive in a usb/sata dock? It's slow as sh*t anyway, so I'm happy to run it off the board. So...stop the array, swap out old drive, put in this replacement...and just run the preclear, before I assign it into the array? CD I just posted version 1.8 of the preclear script that will prompt you if you desire to continue even if you get an initial error from the smartctl command. It will probably work for you. Joe L.
March 13, 201115 yr Author OK, I'm getting this error again when I try to run preclear...just a "regular" preclear, on my old parity drive smartctl is unable to run on /dev/xxx with the -d ata option smartctl: device read identity failed <not an ATA/ATAPI device> A mandatory SMART command failed: exiting. To continue, add one or more '-T permissive' options.$ Remember, my slots are full, so this is with the drive in a usb/sata dock. I precleared the new 2T parity this way...but that was with the old preclear script. Is there somethng about this new preclear, that would make it not like a drive in a usb/sata dock? It's slow as sh*t anyway, so I'm happy to run it off the board. So...stop the array, swap out old drive, put in this replacement...and just run the preclear, before I assign it into the array? CD I just posted version 1.8 of the preclear script that will prompt you if you desire to continue even if you get an initial error from the smartctl command. It will probably work for you. Joe L. Cool. CD
March 13, 201115 yr Author It needs to be 4k-aligned without the jumper and needs to be unaligned with the jumper. If you are going to replace an existing drive and connect it to the motherboard then just set the proper alignment on the options page and start the array and let unRAID clear it. I'm guessing you never installed the jumper and if so you can use the 4k aligned setting. There is no real advantage to having the array offline while you use the preclear. I only say this because you have been using that drive so it really does not need to be burned-in. Otherwise. you can run the newest preclear script with the -n switch. This will skip the pre-reading and post-reading steps and only write zero's to the disk. I only say this because that disk has been used by you for a while and has proven it won't prematurely die. This should make the preclear take about 1/3 the time. You would also use the -A switch to ensure the drive is 4k aligned if you did not install a jumper. If you did install a jumper, then use the -a switch to make sure you do not 4k align the drive. Peter OK, Peter; you're right...no jumper. I'm already set to 4k-alignment for the default partition format. Since I don't need the burn-in, sure I want to save time on this pre-clear. Should I download the latest script, and can I run 2 switches at the same time? Like preclear_disk.sh -n -A /dev/sdx (looks like this is a yes) CD
March 13, 201115 yr can I run 2 switches at the same time? Like preclear_disk.sh -n -A /dev/sdx (looks like this is a yes) CD yes. you can combine those options as in your example.
March 14, 201115 yr Author Marking this thread solved guys. Thanks again for all the help; especially Peter (lionelhutz). Would buy you an online beer if I could...lol CD
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