Upgrading multiple drives (Solved)

[SeeGee]

 I need to swap out some 500G drives with four 6tb drives. These are not hot-swappable. I understand that simply replacing one drive at a time and letting it rebuild is the recommended way, but I'm hoping to get it done in a single sweep to minimize downtime. What's the best course of action here? I understand that I can also simply reset the array config, set up the array from scratch, but will this destroy any existing data or shares? A parity rebuild will be necessary if I use this method I think... 

Edited March 27, 2020 by SeeGee

[JonathanM]

If there is data that you want to keep on the 500GB drives, then you have 2 options. 

 

Rebuild 1 for 1 sequentially, that will keep the data in the same slot, nothing will change except you have more free space.

 

or

 

Rebuild the first drive, copy the data from the other three 500GB to the free space on the drive you just rebuilt, after that is complete set a new config and remove the 3 500GB and replace them with the new drives.

 

Setting a new config doesn't erase any data slots, but if you put new drives in with a new config they will be blank and need to be formatted. If you want to keep data from drives you remove with a new config you have to copy it at some point.

 

Parity doesn't hold any data, it only works with all your existing data drives to emulate 1 missing drive per parity slot. If you remove 4 data drives, nothing can be emulated. If you set a new config, parity must be built with the data drives that you assign.

 

I'm not sure what you mean by minimizing downtime, the array is up and usable during rebuilds. It's not as fast, and continued use will slow down the rebuild considerably, but it's still available.

[SeeGee]

I have no issues migrating all the data off the drives i wish to remove from the array. In fact, i've already moved the majority of it. 

 

What I wanted clarification on was more a question of "What changes when you create a new config?"

 

If I create a new config, will it format/erase data on drives from the old array? (I understand new drives will need to be formatted)

 

If I create a new config, will I need to re-create my users/shares/permissions/docker containers?

 

If shares are not modified, what happens with disk include/exclude lists?

 

Thank you for any insight you can provide!

 

[JonathanM]

6 hours ago, SeeGee said:

If I create a new config, will it format/erase data on drives from the old array?

No.

6 hours ago, SeeGee said:

 

If I create a new config, will I need to re-create my users/shares/permissions/docker containers?

No.

6 hours ago, SeeGee said:

If shares are not modified, what happens with disk include/exclude lists?

Nothing. If the include exclude section no longer matches what is physically installed, you will need to update it manually. If you move a disk containing a share to a slot that was previously excluded by that share, new files written to that share will no longer be written to that disk slot, instead they will be written to the disk slot that is listed in the include / exclude rules, following the other allocation rules of split level and minimum free space.

 

If you mean the global include / exclude, strange things can happen, especially if you move a disk to a slot that is globally excluded, the files, while still on the disk, will not be visible in the user shares.

 

I don't recommend using include / exclude unless you know what you are doing and why.

 

6 hours ago, SeeGee said:

What changes when you create a new config?

The parity disk(s) are built from the new list of data disks.

[SeeGee]

Thank you. This gets me headed in the right direction. It looks like simply :

• moving the data off the disks i wish to remove onto disks I'm keeping,
• then creating a new config with the remaining disks as well as the new disks,
• then rebuild parity

is the way to go.

 

Is it better to rebuild parity before adding the new, blank disks?

[JonathanM]

20 minutes ago, SeeGee said:

is the way to go

Quickest way.

21 minutes ago, SeeGee said:

Is it better to rebuild parity before adding the new, blank disks?

If the new blank disks are tested and known good, then just build parity on everything at once.

 

If the new disks are unknown condition fresh from shipping, then building parity first before adding the new disks will force unraid to do a full capacity write to the new disks when they are added, possibly exposing any manufacturing defects or shipping damage before they participate in protecting the rest of your data.

 

Either way works.

[SeeGee]

They are brand new, shucked wd 6tb. Your insight has been helpful, and I know how I'm going to do this:

 

I'm going to migrate data, create a new array config using only disks I'm keeping, and rebuild parity. While parity is rebuilding, I can start preclear on all new drives that I have installed. One new drives pass preclear, I'll add them to the array. 

[SeeGee]

Just an update: The drives are installed, preclear passed, and parity is currently rebuilding. Thank you for your help.