July 19, 20178 yr Hey guys, so I just wanted to 100% confirm, say I have 5TB of data total in the array, & a mashup of disks (for this example, 3x 2TB & 1x4TB), if I removed the 4TB disk (which does have at least 1TB of data on it) & then followed the removal instructions at https://wiki.lime-technology.com/UnRAID_6_2/Storage_Management#Removing_disks ...this is doable, right? The data just redistributes itself to the other disks? TL;DR: As long as you have enough total disk space for your data, after removing a disk, a parity-sync will redistribute the data without issue? Thanks guys!
July 19, 20178 yr 53 minutes ago, youngnapoleon said: Hey guys, so I just wanted to 100% confirm, say I have 5TB of data total in the array, & a mashup of disks (for this example, 3x 2TB & 1x4TB), if I removed the 4TB disk (which does have at least 1TB of data on it) & then followed the removal instructions at https://wiki.lime-technology.com/UnRAID_6_2/Storage_Management#Removing_disks ...this is doable, right? The data just redistributes itself to the other disks? TL;DR: As long as you have enough total disk space for your data, after removing a disk, a parity-sync will redistribute the data without issue? Thanks guys! Absolutely not! If you remove a disk from the array (do a new config and recompute parity excluding one of your disks), any data on the disk you removed will remain on the disk you removed. It will not be redistributed onto other array disks. After it is removed, you could mount it outside the array and copy the data back onto the array, but 1T will take a while. And until it is complete, the data will not be protected. I think you might want to look into the unbalance plugin. That would redistribute the data from the disk while it remains in the array. Afterwards you could remove the disk and all of the data would remain on the array. Keeping checking in before you do anything significant to confirm you understand the instructions and outcomes. It is easy to make mistakes, and we're happy to help.
July 19, 20178 yr Author 46 minutes ago, bjp999 said: If you remove a disk from the array (do a new config and recompute parity excluding one of your disks), any data on the disk you removed will remain on the disk you removed. It will not be redistributed onto other array disks. Thanks for the response! What would my options be then? Obviously, if a disk with 1TB of data had to be removed due to damage etc, the whole point of the parity is to be able to reconstruct it on a replacement disk. Is there no way to redistribute the data around the already-present disks without having to physically install another?
July 19, 20178 yr Community Expert 2 hours ago, youngnapoleon said: Thanks for the response! What would my options be then? Obviously, if a disk with 1TB of data had to be removed due to damage etc, the whole point of the parity is to be able to reconstruct it on a replacement disk. Is there no way to redistribute the data around the already-present disks without having to physically install another? If you remove a single disk from a parity protected array then the data is still there as unRAID will emulate the missing/damaged disk using the combination of parity plus the other data drives. At this point you are no longer protected against data loss if another drive fails. To get back to a protected state you add in a replacement disk and unRAID rebuilds the contents of the ‘emulated’ drive onto the replacement physical drive. When that completes you are back into a protected state. note that is different to removing a disk drive that you do not intend to replace. If you want to reduce the number of drives then it is your responsibility to handle getting the data of the drive that is to be removed, there is no automated built-in capability in unRAID for this task although plugins such as unBALANCE can help.
July 19, 20178 yr Author Okay, that makes sense. Can the data be moved to the remaining drives from the emulated state?
July 19, 20178 yr Community Expert 1 hour ago, youngnapoleon said: Okay, that makes sense. Can the data be moved to the remaining drives from the emulated state? Yes. The 'emulated' disk will be treated just like the original physical disk as far as accessing its data is concerned.
July 19, 20178 yr Welcome to the forums! You've already demonstrated a valuable skill that many new users lack - asking a question before doing something you don't fully understand. We are all influenced by our experiences and preconceptions, and what we read is colored by those, leading us to not fully grasp everything in the first read. Although tinkering and trying things is part and parcel to learning unRaid, operations that affect array integrity should be confirmed until you fully understand how parity works. When a disk is being simulated (I.prefer that word, but same meaning as emulated), you are in a precarious position. Another disk dropping from the array will cause the simulation to end and your data to be potentially lost. And contrary to what you might think, drives drop for lots of reasons unrelated to actual drive failure. Putting humpty dumpty back together so you can simulate again can get very tricky if a cable is loose and another drive gets kicked. Loose or slightly skewed cables are incredibly common! I would advise that you be extremely careful if you need to enter the case that all connections are secure! Consider investing in drive cages (look at the CSE-M35T-1B). Enjoy your array, and keep asking questions, and you'll avoid your own Waterloo!.:)
July 19, 20178 yr Author Luckily I'm asking this one in advance - my unRAID is currently out of commission due to a near-instant failure of a drive during my trial run haha I'll definitely check out that drive cage, thanks
July 19, 20178 yr Community Expert If you go to Tools - Diagnostics and post the complete diagnostics zip we can help determine the cause of the failure. As already mentioned, often the drive is not to blame.
July 20, 20178 yr Author On 19/07/2017 at 9:47 PM, trurl said: If you go to Tools - Diagnostics and post the complete diagnostics zip we can help determine the cause of the failure. As already mentioned, often the drive is not to blame. Sorry to take so long! It was something I actually already posted on here about: https://forums.lime-technology.com/topic/58394-drives-randomly-missing-cant-rebuild/ Serial Number: WD-WCC4E2ZZFYAH 5 Reallocated_Sector_Ct 0x0033 133 133 140 Pre-fail Always FAILING_NOW 1963 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 24 tbh I haven't really turned it on since & am yet to arrange for the RMA. Starting a new job on Monday & am gonna just buy a new 4TB to take its place before I send it away. Direct link to diag if you're still interested https://forums.lime-technology.com/applications/core/interface/file/attachment.php?id=28757 Edited July 20, 20178 yr by youngnapoleon Added diag link
July 20, 20178 yr Community Expert 2 hours ago, youngnapoleon said: Sorry to take so long! It was something I actually already posted on here about: https://forums.lime-technology.com/topic/58394-drives-randomly-missing-cant-rebuild/ Serial Number: WD-WCC4E2ZZFYAH 5 Reallocated_Sector_Ct 0x0033 133 133 140 Pre-fail Always FAILING_NOW 1963 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 24 tbh I haven't really turned it on since & am yet to arrange for the RMA. Starting a new job on Monday & am gonna just buy a new 4TB to take its place before I send it away. Direct link to diag if you're still interested https://forums.lime-technology.com/applications/core/interface/file/attachment.php?id=28757 Sorry I didn't remember. I read so many posts helping so many people. I'm the one that told you to replace the drive.
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