Hi, 

 

I have 2x Parity drives. 

I want to replace 2 existing Data drives with 2 New drives.

 

Question: Can I swap both out Data Drives and do one rebuild or should I stick to the tried and tested one drive at a time? 

 

A link to the latest best way to swap guide would also be appreciated very much. 

 

Thank you in advance. 

 

If I had dual parity, I would do it one at a time.  The reason being is that the primary reason that many, many folks wanted dual parity was in the event they had to replace a failed disk, that a previously unknown problem on a second disk would not prevent a successful rebuild of the first disk. 

 

Yes, there are ways to recover (in this specific case) if you did have a problem with a third disk while rebuilding two new disks at once but the hassle is definitely not worth the extra few hours of doing two rebuilds rather than one.

50 minutes ago, daytona235 said:

A link to the latest best way to swap guide would also be appreciated very much.

 

    https://wiki.unraid.net/UnRAID_6/Storage_Management#Replacing_disks

 

You could have found this link by clicking on the   'Manual'   link at the bottom right of the GUI screen. 

Thank you - appreciate the advice.

Agree - slow n safe. 

 

Also never noticed that manual link! Whoa! Thank you. 

 

Have a great day. 
 

 

One last question - I read somewhere that pre-clear is no longer necessary cos UNRAID does this automatically? Is this true? 

22 minutes ago, daytona235 said:

One last question - I read somewhere that pre-clear is no longer necessary cos UNRAID does this automatically? Is this true? 

Yes.  The only reason left to run the preclear operation is to 'weed out' any hard disk that have an infant mortality issue.  (I always do it but I usually purchase disks well in advance of installation as I always have a cold spare ready to go.)

 

The only clarification I will make to your question is a nit-picker.  When Unraid does it, it is actually  a clear operation.  And one more minor thing, when Unraid rebuilds a disk, it does not do a clear first.  It only does that when you add a new (additional) disk to the array.