I am running the 5b7 and have quite a few excess disks that are currently assigned and in the array.  However, I thought it might behoove me to remove these drives from the array to use as spares in case of drive failures.  These disks have no files on them, so what would the procedure be to remove them to use as spares?  I'm thinking it would be to stop the array, unassign the disc(s), and then run the initconfig command.  Would I have to preclear these disks again so that I can avoid having unraid prepare the disks after a failure, or can I use them as is?  Or should I approach this a different way?

 

Thanks in advance!

Removing a disk from an array is kind of dangerous, as it requires losing parity and having to rebuild it. If you were to have a drive fail during the parity build, recovery would be difficult to impossible. It is therefore best to not add drives to your array until you need them.

 

But if you want to remove disks, do a parity check first, and closely review the smart reports for signs of a problem. Only then do your initconfig and recreate your array sans the empty disks.

 

You would need to preclear the disks to be able to add them to the array later to avoid having unraid clear them for you. Although they may be empty to you, it is no longer completely full of binary zeros with a preclear signature in place.

But if you want to remove disks, do a parity check first, and closely review the smart reports for signs of a problem.

 

This is a crucial step. Anything can occur while re-creating parity.

On my array recently, a parity test was done, about 10 days later, I upgraded and unRAID decided to upgrade my parity.

a drive failed just as it was doing the upgrade and there was very little I could do via unRAID to recover the data.

 

I had to resort to some external tool to copy the drive sans bad sectors.

 

So before you adjust the array, do a parity check and do a review of all smart status.

 

 

So before you adjust the array, do a parity check and do a review of all smart status.

 

 

Thanks for the advice guys.  So do you mean to run SMART on all the drives or just those I'll remove?  And are short tests sufficient or would I have to run long tests?

 

Thanks again...

 

So before you adjust the array, do a parity check and do a review of all smart status.

 

 

Thanks for the advice guys.  So do you mean to run SMART on all the drives or just those I'll remove?  And are short tests sufficient or would I have to run long tests?

 

Thanks again...

 

smartctl -t short  on ALL drives that are part of the array.

Review each log for pending sectors or read failed at LBA:

 

smartctl -t short  on ALL drives that are part of the array.

Review each log for pending sectors or read failed at LBA:

 

Great... thanks for the clarification. 

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

Be careful with the "dd" command though...I almost lost a drive because I was hung over and typed the drive in the example instead of the one I wanted to remove!!  All in all, the procedure worked great so I would recommend doing it to get your drives removed without losing parity just be careful with those dd command lines that everything is EXACT!

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

This will NOT WORK with the latest 5.0 Betas.

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

This will NOT WORK with the latest 5.0 Betas.

I hope there will be a new procedure that will work before 5.0 goes final. What invalidates the current procedure on the 5 series?

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

Be careful with the "dd" command though...I almost lost a drive because I was hung over and typed the drive in the example instead of the one I wanted to remove!!  All in all, the procedure worked great so I would recommend doing it to get your drives removed without losing parity just be careful with those dd command lines that everything is EXACT!

 

I would never use this procedure. Too easy to make a critical mistake.

It seems people are paranoid of a drive failure while recreating parity.

 

But this is also why to evaluate all smart logs and do a parity check before any other destructive procedure.

 

I am planning to also do a monthly badblock read test on every drive since my latest failure.

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

Be careful with the "dd" command though...I almost lost a drive because I was hung over and typed the drive in the example instead of the one I wanted to remove!!  All in all, the procedure worked great so I would recommend doing it to get your drives removed without losing parity just be careful with those dd command lines that everything is EXACT!

 

I would never use this procedure. Too easy to make a critical mistake.

It seems people are paranoid of a drive failure while recreating parity.

 

But this is also why to evaluate all smart logs and do a parity check before any other destructive procedure.

 

I am planning to also do a monthly badblock read test on every drive since my latest failure.

 

Weebo i see you have your own safe type of disk physical checking routine besides the parity check of the unRAID itself...

can you please post your steps and command for the various programs you are now using in your setup or maybe even get it added to the wiki under best practices ?

 

thanks

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

Be careful with the "dd" command though...I almost lost a drive because I was hung over and typed the drive in the example instead of the one I wanted to remove!!  All in all, the procedure worked great so I would recommend doing it to get your drives removed without losing parity just be careful with those dd command lines that everything is EXACT!

 

I would never use this procedure. Too easy to make a critical mistake.

It seems people are paranoid of a drive failure while recreating parity.

 

But this is also why to evaluate all smart logs and do a parity check before any other destructive procedure.

 

I am planning to also do a monthly badblock read test on every drive since my latest failure.

 

Weebo i see you have your own safe type of disk physical checking routine besides the parity check of the unRAID itself...

can you please post your steps and command for the various programs you are now using in your setup or maybe even get it added to the wiki under best practices ?

 

thanks

 

I'm still working it out, but there will definitely be something to come in the the next couple of weeks.

I really got caught with my pants down in this situation and it could have been catastrophic for me.

I just used this procedure on my server running 4.7:

 

http://lime-technology.com/forum/index.php?topic=2591.0

 

Be careful with the "dd" command though...I almost lost a drive because I was hung over and typed the drive in the example instead of the one I wanted to remove!!  All in all, the procedure worked great so I would recommend doing it to get your drives removed without losing parity just be careful with those dd command lines that everything is EXACT!

 

I would never use this procedure. Too easy to make a critical mistake.

It seems people are paranoid of a drive failure while recreating parity.

 

But this is also why to evaluate all smart logs and do a parity check before any other destructive procedure.

 

I am planning to also do a monthly badblock read test on every drive since my latest failure.

 

Weebo i see you have your own safe type of disk physical checking routine besides the parity check of the unRAID itself...

can you please post your steps and command for the various programs you are now using in your setup or maybe even get it added to the wiki under best practices ?

 

thanks

 

I'm still working it out, but there will definitely be something to come in the the next couple of weeks.

I really got caught with my pants down in this situation and it could have been catastrophic for me.

 

looking forward to it thanks....