March 10, 201115 yr Never hurts to be sure; an ounce of prevention...that kind of thing. So...I've run Pre-clear on my 2T EARS (man...no room in the array, so I did it from a usb/sata dock...and it took ~65 hours ). So now I just stop the array...unassign the parity...switch out the drives...re-assign the new parity...bring the array back online...and rebuild? BTW, it's been a while...but I thought the Pre-clear did a SMART report, or something. Where/how do I determine if it "passed"? CD
March 10, 201115 yr Never hurts to be sure; an ounce of prevention...that kind of thing. So...I've run Pre-clear on my 2T EARS (man...no room in the array, so I did it from a usb/sata dock...and it took ~65 hours ). So now I just stop the array...unassign the parity...switch out the drives...re-assign the new parity...bring the array back online...and rebuild? BTW, it's been a while...but I thought the Pre-clear did a SMART report, or something. Where/how do I determine if it "passed"? CD If you used the most recent preclear_disk.sh there will be a directory on your flash drive named "preclear_reports" Look in it.
March 10, 201115 yr To answer the first question, yes just swap the drives and then when you start unRAID will build the parity onto the new drive. Just before you do it, the EARS are advanced format and suffer performance issues if not properly aligned. So, did you get the drive 4k aligned properly? There is no filesystem on a parity disk but there is still a partition that needs to be properly aligned. Peter
March 10, 201115 yr Author Never hurts to be sure; an ounce of prevention...that kind of thing. So...I've run Pre-clear on my 2T EARS (man...no room in the array, so I did it from a usb/sata dock...and it took ~65 hours ). So now I just stop the array...unassign the parity...switch out the drives...re-assign the new parity...bring the array back online...and rebuild? BTW, it's been a while...but I thought the Pre-clear did a SMART report, or something. Where/how do I determine if it "passed"? CD If you used the most recent preclear_disk.sh there will be a directory on your flash drive named "preclear_reports" Look in it. I guess not...'cuz there's not. Can I just run a SMART test in unRAID...before I put it in the array? CD
March 11, 201115 yr Author To answer the first question, yes just swap the drives and then when you start unRAID will build the parity onto the new drive. Just before you do it, the EARS are advanced format and suffer performance issues if not properly aligned. So, did you get the drive 4k aligned properly? There is no filesystem on a parity disk but there is still a partition that needs to be properly aligned. Peter Nope; that stuff's all pretty new to me. That's why I returned the hd204ui for this. So I'm still not plug-n-play, huh? LOL Sorry...can someone direct me to the post on how to properly align this drive. CD
March 11, 201115 yr Did you install a jumper? Did you use the -A switch on the preclear? Are you runing 4.7? If so, did you set the default partition format to MBR: 4k aligned? Peter
March 11, 201115 yr Author Did you install a jumper? Did you use the -A switch on the preclear? Are you runing 4.7? If so, did you set the default partition format to MBR: 4k aligned? Peter NO NO NO I was gonna get on 4.7 after. Guess that's where I should start...before? CD
March 11, 201115 yr First upgrade to 4.7 and then do a parity check. Concurrent with the parity check, preclear the drive with the -A option.
March 11, 201115 yr Yes, I would update to 4.7 first. Then run a parity check to make sure everything is happy. Next is to go to the options page and set the default partition format to MBR: 4k aligned so you won't have the problem again. The newest preclear script will recognize and support this option so the drives get properly formatted. Don't worry, this can be applied to every new disk advanced format or not. Now, run the preclear with a switch which will quicky move the parition to sector 64, which is what you want for a WD EARS without a jumper. Try in the preclear thread or Joe L. to find out the switch to use. I don't know what it is offhand and don't know where to find it besides looking in the preclear thread. You 100% do not have to run the whole preclear again. Finally, assign the drive as parity and let it build parity onto the drive. Someone recently reported that their write speeds increased by about 10MBps when they aligned their EARS parity drive to sector 64 so it does make a significant difference with the EARS drives. Peter
March 11, 201115 yr Author Yes, I would update to 4.7 first. Then run a parity check to make sure everything is happy. Next is to go to the options page and set the default partition format to MBR: 4k aligned so you won't have the problem again. The newest preclear script will recognize and support this option so the drives get properly formatted. Don't worry, this can be applied to every new disk advanced format or not. Now, run the preclear with a switch which will quicky move the parition to sector 64, which is what you want for a WD EARS without a jumper. Try in the preclear thread or Joe L. to find out the switch to use. I don't know what it is offhand and don't know where to find it besides looking in the preclear thread. You 100% do not have to run the whole preclear again. Finally, assign the drive as parity and let it build parity onto the drive. Someone recently reported that their write speeds increased by about 10MBps when they aligned their EARS parity drive to sector 64 so it does make a significant difference with the EARS drives. Peter OK...I installed 4.7 last night, ran parity overnight (no errors), and set the default partition format to 4k aligned. Now what, I should download the latest preclear script and run it with an -a switch? Remember, my hot-swap bays are full...so I ran it the first time off a usb/sata dock, and it took ~65 hours! I know this -a switch speeds things up (because it's only looking at the 4k sector?), but how long should I expect it to take? CD
March 11, 201115 yr The switch is not -a or -A, those represent sector 63 or sector 64 alignment. You never want to use -a in the future when preclearing a disk. I'll look the switch up for you. From the first post in the preclear_disk.sh thread; "Added -C 64 option to quickly convert a precleared disk from a sector 63 to 64 start" So, run it with the "-C 64" switch and it will just move the partition. Should take almost no time. FYI, the Reiser file system uses 4k blocks so aligning the internal 4k sectors of the drive to the filesystem 4k block usage is the reason you want to do this. Peter
March 11, 201115 yr Author The switch is not -a or -A, those represent sector 63 or sector 64 alignment. You never want to use -a in the future when preclearing a disk. I'll look the switch up for you. From the first post in the preclear_disk.sh thread; "Added -C 64 option to quickly convert a precleared disk from a sector 63 to 64 start" So, run it with the "-C 64" switch and it will just move the partition. Should take almost no time. FYI, the Reiser file system uses 4k blocks so aligning the internal 4k sectors of the drive to the filesystem 4k block usage is the reason you want to do this. Peter Thanks Peter; you are a "hero" member...lol. Too bad this forum doesn't let you give dap, like some other sites. A thanks will have to do. CD
March 11, 201115 yr No problem. On the main unRAID page you can click on the cache disk and confirm the alignment. Peter
March 11, 201115 yr Author OK, well...my drive didn't come with a jumper. Not that big a deal; I'll find one at work...but do I need the jumper before I run the -C 64 switch? CD
March 11, 201115 yr Do not install the jumper on that drive. I don't recommend ever changing the jumper on a EARS drive once you have started using it. The 4k aligned setting and the new preclear script will take care of the EARS drive. So, just run the preclear with the -C 64 switch and stick it in the array. Peter
March 11, 201115 yr Author Did you install a jumper? Did you use the -A switch on the preclear? Are you runing 4.7? If so, did you set the default partition format to MBR: 4k aligned? Peter I'm confused CD
March 12, 201115 yr Once you set 4k-aligned in unraid preclear will use 4k-aligned. Since you have already precleared the disk, but with a 4K-unaligned setting you can change the alignment to 4K-aligned quickly by running preclear -C 64
March 12, 201115 yr Author Once you set 4k-aligned in unraid preclear will use 4k-aligned. Since you have already precleared the disk, but with a 4K-unaligned setting you can change the alignment to 4K-aligned quickly by running preclear -C 64 Yes...but I thought in one post Peter was saying I needed to set a jumper, and in another NOT to use a jumper? CD
March 12, 201115 yr I only asked if you had installed a jumper to know if you had or not.The question did not mean you had to install one. The question was because with a jumper you should not 4k align the disk. I can not tell you the proper thing to do until you answered that. You are using 4.7 now so you can 4k align the disk and you do not need the jumper when you 4k align the disk. Peter
March 12, 201115 yr Author I only asked if you had installed a jumper to know if you had or not.The question did not mean you had to install one. The question was because with a jumper you should not 4k align the disk. I can not tell you the proper thing to do until you answered that. You are using 4.7 now so you can 4k align the disk and you do not need the jumper when you 4k align the disk. Peter Gotcha! CD
March 12, 201115 yr Author OK... command is preclear_disk.sh -C 64 /dev/xxx right? This is with the latest preclear script...I'm getting 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.$ CD
March 12, 201115 yr 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
March 12, 201115 yr Author Did you get the wrong device??? Peter I don't know what you mean by wrong device? I have it attached to my server via usb/sata dock; it's showing up as sdg and sdg1 in partitions not in array. You know what...do I need to reboot about loading the latest preclear onto the boot drive? CD
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