Adding new drives to an array

[ashman70]

I am doing a parity sync on a new build with 5 drives at the moment. In the near future I am going to want to add 3 more drives. Is the process to stop the array, add one drive at a time, completing a parity sync for each new drive I add? Or can I add all three new drives at the same time and do a parity sync? Or do I do a new config and add the three drives all at once?

[itimpi]

That is not quite the process!

 

The default process when you add a drive is that unRAID takes the array offline while the drive is cleared (written with zeroes) which means the parity is not changed.  This can take many hours for a large disk.

 

An alternative that most users use is to 'preclear' the disk before adding it to the array (there is a plugin for this) which can be done while the array is in use.  If this approach is used then the array can be bought online immediately after the drive has been added so the array downtime is only seconds.  The preclear process also acts as a confidence check on the drive before adding it to the array.

[ashman70]

Sorry I should have added the assumption that the drives I am adding have already been precleared. Just wondering what the process is to add them to the array and to start the array. One at a time with a parity sync, or all at once?

[itimpi]

Sorry I should have added the assumption that the drives I am adding have already been precleared. Just wondering what the process is to add them to the array and to start the array. One at a time with a parity sync, or all at once?

if they are precleared you can stop the array, add all of them and restart the array.  At that point you will be told they are unformattted and given the option to format them.  Doing this only takes a minute or so.    There is no need to do a parity sync as since the disks were precleared parity is maintained.

[joedotmac]

I'm uncertain of the current add drive to existing array process.  The wiki for adding a drive has a pre-clear process, documentation states the plugin is broken as of 8/28/2016.    https://lime-technology.com/wiki/index.php/Add_One_or_More_New_Data_Drives

 

I discovered the text of the plugin being broken after being 12+ hours and 96% into using the plugin for pre-clearing.  Not sure what is broken about the plugin, no indication is given.  Nor certain of what the process is for adding a new drive to the array.

 

 

 

 

[Helmonder]

Unraid will no longer pause the array while clearing it.. This used to be the case, is no more.

 

Just stop the array, add all your drives and start the array again. The webinterface will ask you permission to format/add the drives to the array... That is all.

 

If you want to check your drives intensively on forehand you can use the preclear process.

[joedotmac]

I originally did a xfs format on the drive, unraid complained then complained it was unmountable.  I've now finished the drive preclear as suggested using the available plugin.

 

Here's a couple fantastic video tutorials.  These should be part of the wiki.

 

 

 

 

[kizer]

Personally I still use the Old Fashion console version of Preclearing. I just use an old machine that is not used for anything other than well preclearing. I could just use my unRAID machine and not assign the drive to the array, but I hardly ever do. The plugin makes things rather convenient, but I'm old school about it I guess.

[Lantesh]

Or do I do a new config and add the three drives all at once?

 

Whatever you do DON'T do a "new config."  You are adding drives, not creating an entirely new configuration.

[garycase]

I am doing a parity sync on a new build with 5 drives at the moment. In the near future I am going to want to add 3 more drives. Is the process to stop the array, add one drive at a time, completing a parity sync for each new drive I add? Or can I add all three new drives at the same time and do a parity sync? Or do I do a new config and add the three drives all at once?

 

Given the subsequent discussion, where it's clear you already pre-cleared the drives; then Yes, simply Stop the array; add all 3 drives; and then Start the array.  Be sure your default format is set as desired (probably XFS) before doing this ... and then when you Start the array it will automatically format the new drives (there's a box you'll have to check to say this is okay).

 

Done 

 

Note that even if the drives weren't pre-cleared you could do the same thing -- the newest version of UnRAID will clear the drives before actually completing the add, so the array won't be offline during this process (as it was with earlier versions).

 

Finally, even though the drives were pre-cleared, I'd still do a parity check after you've added them.  In fact, I'd do a parity check BEFORE making any changes, just to be sure everything's "perfect" before changing the array.