Best way to remove data drive

[wgstarks]

I want to remove an empty data drive from my configuration so that I can do a little testing with the preclear package. I'm sure I probably need to stop the array first. But not sure how to proceed from there. Can I just do a "New Config" or must I shutdown the server, remove the disk and then start the server?

[SSD]

I want to remove an empty data drive from my configuration so that I can do a little testing with the preclear package. I'm sure I probably need to stop the array first. But not sure how to proceed from there. Can I just do a "New Config" or must I shutdown the server, remove the disk and then start the server?

 

There are basically two ways to do this.

 

1 - Do a new config and redefine the array without that disk. Parity will rebuild. You assume a certain element of risk that a disk failure won't occur during the parity build, but the chances are very small, especially if you are monitoring your SMART reports for signs of failure.

 

2 - You say the disk is empty - but even the most empty data disk still has non-zero data created when the disk is partitioned and formatted. Empty of files does not mean invisible to parity. But there is a way to make a disk invisible to parity - and that is to fill it with binary zeros. Doing so would update parity in the process, and when you are done you could do a new config, trust parity, and define the array without that disk.

 

Some people want to remove a disk and maintain its contents (it would act like a backup). Doing #2 obviously makes that impossible. But for your application I'd certainty consider #2. There are several threads on how to do this. Post back if you want to proceed and can't find the instructions. It does require dropping to the command line which is a non-starter for some.

[JonathanM]

I want to remove an empty data drive from my configuration so that I can do a little testing with the preclear package. I'm sure I probably need to stop the array first. But not sure how to proceed from there. Can I just do a "New Config" or must I shutdown the server, remove the disk and then start the server?

 

There are basically two ways to do this.

 

1 - Do a new config and redefine the array without that disk. Parity will rebuild. You assume a certain element of risk that a disk failure won't occur during the parity build, but the chances are very small, especially if you are monitoring your SMART reports for signs of failure.

 

2 - You say the disk is empty - but even the most empty data disk still has non-zero data created when the disk is partitioned and formatted. Empty of files does not mean invisible to parity. But there is a way to make a disk invisible to parity - and that is to fill it with binary zeros. Doing so would update parity in the process, and when you are done you could do a new config, trust parity, and define the array without that disk.

 

Some people want to remove a disk and maintain its contents (it would act like a backup). Doing #2 obviously makes that impossible. But for your application I'd certainty consider #2. There are several threads on how to do this. Post back if you want to proceed and can't find the instructions. It does require dropping to the command line which is a non-starter for some.

As an added bonus for option 2, if you accidently type the wrong destination for the zeroing process, you will pretty much irretrievably erase whatever you sent the zeroes to. It also takes a fair amount of time to complete, at least as long as recalculating parity with the new config option.

 

Since you say you want to do testing, is it a fair assumption that this server is fully backed up and not going to cause you grief if you accidently kill some data on it? If that's the case, I'm assuming you want to spend as little time as possible removing the drive, which would mean using option 1, since you can start playing with the drive as soon as it is unassigned.  If you want the safest option available, then go option 2 with checks and double checks before you start so you know how to tell that you are operating on the correct drive and not possibly killing your data. The removed drive won't be available to test until the process is complete.

[wgstarks]

Thanks. I think I'll go with Option 1. I used my 4TB standby disk to be able to re-shuffle all my video files in order to re-format each disk to XFS one at a time. Now the smallest disk contains no video files since I just re-formatted it. I'll take it out of the array so I can use it to test notifications with the perclear package. Can't seem to get the emails to work.