Upgrading multiple disks, what's the best practice?

[truthfulie]

I'm upgrading about 12 disks to a larger ones with one parity in the system. Current disks are mostly 10TBs with one 3TB and one 6TB in the mix. Upgrading all to 12TB disks. There are two fresh new drives that was added to the array so there are fair bit of usable storage within the array.

 

One has been replaced and going through the rebuild process right now. Been about twenty hours and still about twenty more to go. It was little faster at first but seems to have settled at about 90MBps on average. Using dockers like Plex or just reading files off the array in general (I'm not writing to the array) does make the rebuild process go much slower to the point where it's not feasible. So with 11 more to go, it'll take quite awhile to go through this process each time I replace a disk. Is there something else I could do to make the upgrade process go a little faster? I don't mind not being able to write to the array or having no parity protection for awhile if it means I can reduce the rebuild time significantly.

 

Perhaps remove the parity from the system, move files to the new drives, replace, move back, rinse and repeat? Perhaps expand the array with the new disks, move files to it, remove old ones and shrink the array? Never done an upgrade of this scale (I've always just expanded the array but 15 is my current hardware limitation) so all this is kind of new to me. Thoughts?

 

[theruck]

how much data in total you have?

[chris smashe]

If your are going to build each disk from parity you should have updated your parity disk first and rebuilt parity. From what i am reading your parity drive currently is at most 10tb and you put in a 12tb data disk. Your parity drive needs to be as big or bigger then your biggest data disk or it pretends that your 12tb disk is only 10tb.

 

If you don't care about the parity like you said you could

 

1. remove the parity drive

then go through each drive one by one and

2. add replacement drive in as an unassigned disk

3. copy the data from one of your old disks to the new disk using midnight commander or something better that i don't know about.

4. remove the old disk from the array and replace with the new disk

5. repeat with each disk until you are done transferring data.

6. Add in the parity disk and rebuild parity.

 

you will still have all the data on your old disks in case you need it for some reason but if one fails while this is happening the data will be gone since you no longer have parity to restore from.

Additional note: Stop all dockers and things that will write to the array while you are doing this transfer. If you tell the system to copy files and a new file gets added to the disk while doing the copy that new file might not go with it so when you change drives it will no longer be there. You could add the old disk back in as an unassigned disk and copy the file over but its just best to not be writing while you are doing the data transfer.

 

Edited October 22, 2022 by chris smashe

[truthfulie]

5 hours ago, theruck said:

how much data in total you have?

About 90 TB of data on the array.

 

1 hour ago, chris smashe said:

If your are going to build each disk from parity you should have updated your parity disk first and rebuilt parity. From what i am reading your parity drive currently is at most 10tb and you put in a 12tb data disk. Your parity drive needs to be as big or bigger then your biggest data disk or it pretends that your 12tb disk is only 10tb.

Yeah, I've done that already. The parity has been upgraded to 12TB drive and parity sync was done.

 

1 hour ago, chris smashe said:

you will still have all the data on your old disks in case you need it for some reason but if one fails while this is happening the data will be gone since you no longer have parity to restore from.

I didn't think I cared about parity because shares aren't protected while rebuild is happening, but as you mentioned, I would have the old disk in case something goes wrong while rebuild is happening. Looks like I'll just take the slow but safe route and go through the rebuild process. After passing 6TB, speed seems to have picked up a bit at around 120MBps. Thanks for the detailed response.

 

 

 

 

[theruck]

if you can afford smaller outages i would consider to build a parallel unraid server with 8 drives and copy it over