Mat1926 Posted April 21, 2018 Share Posted April 21, 2018 All my disks are at ~85% of usage, except the 1st one it is @ 94% and I am getting notifications every time it goes up by 1%. I am curious, is this how unRaid works? Why it does not copy the data to the other disks since all the remaining disks are below 90%? Also, shall I worry about that, or is unRaid handling everything just fine?.... Thnx Link to comment
itimpi Posted April 21, 2018 Share Posted April 21, 2018 UnRAID never automatically moves files from one share to another - doing so always has to be a manual process (although plugins such as UNBalance can help with this). The disk that is selected for new files is determined by the combination of Split Level and Allocation method specified for a share (with Split Level winning any contention). It sounds as if Split Level is what is causing new files to go to the nearly full disk? Without more detail on the Share settings and the actual path of the files being copied this is just a guess. Link to comment
Mat1926 Posted April 21, 2018 Author Share Posted April 21, 2018 3 minutes ago, itimpi said: UnRAID never automatically moves files from one share to another - doing so always has to be a manual process (although plugins such as UNBalance can help with this) I did not mean moving existing files, what I meant was when I copy new ones to the system...So what would happen if it reached 100%? Split is set to Automatic Allocation method is set to High-Water Link to comment
Mat1926 Posted April 21, 2018 Author Share Posted April 21, 2018 I looked at the settings, and I can disable the notification, but is that a good idea? Also, the minimum free space for the disks is set @ 0 KB, is this good bad? Can I adjust this value, or it should be set only once?! Thnx Link to comment
pwm Posted April 21, 2018 Share Posted April 21, 2018 You should set minimum free space to be no less than the largest file you prepare to transfer - just so unRAID will not start the copy to the almost full disk and then run out of space before having written all data. Link to comment
Mat1926 Posted April 21, 2018 Author Share Posted April 21, 2018 Some of my files exceeds 50 GB in size, shall I adjust the value now? Does this affect my system at all? What if a file was bigger, what can I do in that case? re-adjust again is slightly strange.... Link to comment
pwm Posted April 21, 2018 Share Posted April 21, 2018 9 minutes ago, Mat1926 said: Some of my files exceeds 50 GB in size, shall I adjust the value now? Does this affect my system at all? What if a file was bigger, what can I do in that case? re-adjust again is slightly strange.... Most programs do not preallocate space when they start to write - so unRAID can't know how large the file is. Which means unRAID can't know that one disk has too little space and that the file copy must be started on some other disk. Setting a minimum free space of 50 GB means unRAID will not start to copy to that disk unless there is at least 50 GB free - which then means files below 50 GB will not fail to copy. You can change the value as often as you like. If you need to copy really huge files and aren't willing to set the reservation limit so high, then you might have to manually copy to a specific disk for your really huge files - or increase the reservation and start the copy and then shrink the reservation again. Link to comment
Mat1926 Posted April 21, 2018 Author Share Posted April 21, 2018 @pwm What if a disc utilization is @ 100%...Does this affect its read/write performance? Thnx Link to comment
pwm Posted April 21, 2018 Share Posted April 21, 2018 How full the drive is doesn't affect the read and write speeds directly - but can indirectly affect it. First off, a modern HDD has different transfer speeds for inside and outside tracks - so many server disks uses short-stroking and only uses the outside tracks to get higher transfer speeds. But the most important thing is the outcome of disk fragmentation. With a mostly empty drive, the file system layer have multiple options for where to allocate new file data. When the disk is almost full, then the file system layer needs to make use of even small holes of free space to find room for more file or meta data. Some file systems will lose lost of write speed when almost full. And if the last files added results in a large number of fragments, then this will also affect the read speed when reading these files. For an archive disk, that you just fill with new content, is generally ok to fill the drive very full. But if it's a work disk where you regularly erase or extend files - or in case of copy-on-write (CoW file systems like BTRFS) where you regularly modifies files - then you should leave a healthy number of percent free, to give the file system layer better options to avoid fragmentation. Link to comment
Mat1926 Posted April 21, 2018 Author Share Posted April 21, 2018 32 minutes ago, pwm said: For an archive disk, that you just fill with new content, is generally ok to fill the drive very full. But if it's a work disk where you regularly erase or extend files - or in case of copy-on-write (CoW file systems like BTRFS) where you regularly modifies files - then you should leave a healthy number of percent free, to give the file system layer better options to avoid fragmentation. Is there an option in unRAID to leave some free space on a disc instead of 100% utilization, or that does not make sense at all?! My case is archive, but I am asking just in case... Thnx Link to comment
pwm Posted April 21, 2018 Share Posted April 21, 2018 Set minimum free space for your shares. Link to comment
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