Guys

 

I have a 1tb drive in my server that I would like to swap for a new 2tb drive.  Normally an easy enough task, letting unRAID rebuild the data on the new disk.  Here's the thing, I don't want to actually rebuild the data and just want the new "blank" 2tb drive.  I use this specific drive as my the backup drive for my main workstation.  Ideally, I would like to pull the 1tb, replace it with the new 2tb and just run a new backup from my workstation.  Is this possible?  My logic is that not having all the drives spun up and rebuilding is a good thing from a drive longevity standpoint.

 

Ideas welcome.

 

Thanks!

Jim

Guys

 

I have a 1tb drive in my server that I would like to swap for a new 2tb drive.  Normally an easy enough task, letting unRAID rebuild the data on the new disk.  Here's the thing, I don't want to actually rebuild the data and just want the new "blank" 2tb drive.  I use this specific drive as my the backup drive for my main workstation.  Ideally, I would like to pull the 1tb, replace it with the new 2tb and just run a new backup from my workstation.  Is this possible?  My logic is that not having all the drives spun up and rebuilding is a good thing from a drive longevity standpoint.

 

Ideas welcome.

 

Thanks!

Jim

 

You might want to read the FAQ and understand better how parity works.  Once a disk is in the array, all of its values are incorporated into the parity values.  You cannot just remove a disk without rendering parity useless.  (There is one time consuming method of removing a disk that requires zeroing out the entire disk you want to remove, making it "invisible" from a parity perspective.  But that's another topic.)

 

Before using your new 2T disk, you really should run preclear on it to give it a good burnin test.

 

You should also run a parity check on your array to make sure your array parity is in good shape and disks are fully readable.

 

You should also backup your config directory.

 

From there you have 2 choices ...

 

1 - Let unRAID rebuild the 1T disk onto the 2T disk.  True, you don't need the data, but you can easily delete the data afterwards and parity will be maintained throughout.  If you did have a disk failure during the rebuild, you'd be able to put the 1T back into its original configuratin, restore the config directory, and do a recovery. 

 

2 - You can reinitialize your array (push "Restore" button or run initconfig, depending on unRAID version).  Afterwards you can include or exclude any disks you want in the array configuration.  When you start the array, the parity will be recalculated based on the new array configuration.  Since you just did a parity check, the chances of a disk failure in the middle are slight, but if it were to happen, similar to above, you could recover.

 

In the end, both are pretty similar from a duration and risk perspective.

 

3 - I guess there is one more option - that is to add the new 2T disk to the array without removing the 1T one.  After the preclear, you could do this very quickly.  Of course you may have other limitations (no more slots, no more ports) to do this.  But if you could do it, you could zero out the 1T drive and remove it aftewards.

 

Hope this helps.  Post back with any further questions.

You should also run a parity check on your array to make sure your array parity is in good shape and disks are fully readable.

 

You should also backup your config directory.

Excellent advice

From there you have 2 choices ...

1 - Let unRAID rebuild the 1T disk onto the 2T disk.  True, you don't need the data, but you can easily delete the data afterwards and parity will be maintained throughout.  If you did have a disk failure during the rebuild, you'd be able to put the 1T back into its original configuratin, restore the config directory, and do a recovery.

It would take a special command or two to force the disk that removed and the old config folder to be used to recover, but it could.  If it takes 10 hours to rebuilt the 1TB drive onto the 2TB drive, you are without parity protection for those 10 hours.

 

2 - You can reinitialize your array (push "Restore" button or run initconfig, depending on unRAID version).  Afterwards you can include or exclude any disks you want in the array configuration.  When you start the array, the parity will be recalculated based on the new array configuration.  Since you just did a parity check, the chances of a disk failure in the middle are slight, but if it were to happen, similar to above, you could recover.

Actually I don't think you could recover from a disk failure unless it was the one just substituted.  As soon as you start newly calculating parity on the new configuration it is useless for recovery purposes until it is fully completed.  If it takes 10 hours to initially calculate parity, you are without parity protection until that initial parity calculation is completed.

In the end, both are pretty similar from a duration and risk perspective.

 

3 - I guess there is one more option - that is to add the new 2T disk to the array without removing the 1T one.  After the preclear, you could do this very quickly.  Of course you may have other limitations (no more slots, no more ports) to do this.  But if you could do it, you could zero out the 1T drive and remove it aftewards.

 

Hope this helps.  Post back with any further questions.

Both methods have some affiliated risk of data loss if another disk were to fail.  The time without parity protection will be very similar in both cases.

 

Joe L.

Joe is right - option 2 only provides possibility to recover from a disk failure while building parity if you are replacing the parity drive at the same time.