Mr.Cake Posted August 24, 2022 Share Posted August 24, 2022 (edited) Around 18 months ago i expanded my array by adding another 2 8tb disks, ever since then reconstruct write doesn't seem to work as it should. With reconstruct write on unraid is still reading from the destination disk and also the parity disk. Slowing down operations to basically read/modify/write speeds. I've ignored it up until now. Tried to google the answer myself but every post talks about slow write speeds not the fact that disk is still reading when it shouldn't be. Pre array expansion with 'Turbo write' on i would see pure writing to destination and parity, now you see as below. Anything i can do to fix this? File copy from disk 1 > disk 3 Reconstruct write on Reconstruct write off unraid-diagnostics-20220824-1902.zip Edited August 24, 2022 by Mr.Cake grammar Quote Link to comment
Kilrah Posted August 24, 2022 Share Posted August 24, 2022 (edited) That's because you're also reading from the array, when you do so it'll bounce back and forth between both modes. If your copy source is not on the array you'll see what you expect. Full speed reconstruct write needs full read bandwidth from all drives, so if you're also reading from one it'll be impossible to achieve and you'll end up with pretty much the same situation than read-modify-write where a disk has to seek back and forth. Edited August 24, 2022 by Kilrah Quote Link to comment
Mr.Cake Posted August 24, 2022 Author Share Posted August 24, 2022 With reconstruct write / turbo write on you can copy and move files between disks in the array without any speed penalty. Which is how it was working before adding extra drives. Quote Link to comment
JorgeB Posted August 24, 2022 Share Posted August 24, 2022 1 minute ago, Mr.Cake said: With reconstruct write / turbo write on you can copy and move files between disks in the array without any speed penalty No you cannot, it's as mentioned above. Quote Link to comment
Mr.Cake Posted August 24, 2022 Author Share Posted August 24, 2022 Ok. Here is a copy from cache drive to drive 4 with turbo write enabled. Exhibits the same behaviour albeit with less reading. Quote Link to comment
JorgeB Posted August 24, 2022 Share Posted August 24, 2022 Something else is still reading from that drive. Quote Link to comment
Mr.Cake Posted August 24, 2022 Author Share Posted August 24, 2022 Yeah and that's my issue. What could it be? Or how can i find it. Quote Link to comment
Kilrah Posted August 24, 2022 Share Posted August 24, 2022 You can try the "Open Files" plugin. Quote Link to comment
Mr.Cake Posted January 14, 2023 Author Share Posted January 14, 2023 Since i haven't found a solution, I'm going to recreate the array to try and fix this. Am I able to keep the cache drive as storage while removing all the spinners from the array? I'll be zeroing the drives if necessary, is there some way to have unraid forgot drive assignments so i can test if that fixes it first? To be clear i've removed all plugins, docker is off, no vm's and it still happens. For whatever reason unraid feels the need to read from destination disk when it doesn't need to. The reading only occurs when you start a transfer. Would be great to know why this has happened though, won't be able to restart next time. I think seafile might be breaking diagnostics , attach what it has grabbed before it fails. unraid-diagnostics-20230115-0204.zip Quote Link to comment
JorgeB Posted January 15, 2023 Share Posted January 15, 2023 20 hours ago, Mr.Cake said: Am I able to keep the cache drive as storage while removing all the spinners from the array? You can keep it intact but won't be able to used without any array devices assigned. 20 hours ago, Mr.Cake said: is there some way to have unraid forgot drive assignments so i can test if that fixes it first? Tools -> New config Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.