Hard drive swap questions

[zryder]

Just thought I would confirm my assumptions before I do something dumb.

I have an Unraid server running with 1 2.0t drive as the parity drive, 1 2.0t, 3 1.5, and 1 500g drive as data drives.

I have another 2.0 coming in today.

If I removed the 500g, and put the 2.0 in its place, the parity drive should rebuild the data on the new 2.0, and everything will be fine in the end, right?

Should I pre-clear the new 2.0?

[Joe L.]

Just thought I would confirm my assumptions before I do something dumb.

I have an Unraid server running with 1 2.0t drive as the parity drive, 1 2.0t, 3 1.5, and 1 500g drive as data drives.

I have another 2.0 coming in today.

If I removed the 500g, and put the 2.0 in its place, the parity drive should rebuild the data on the new 2.0, and everything will be fine in the end, right?

Correct. 

 

You might want to perform a full parity check before you do anything to identify any problems on the disks that will be used in the re-construction process, before you make any changes.

 

Just be absolutely certain to use the "Start" button to begin the re-construction of the old 500Gig disk contents onto the new 2T disk.

 

Do NOT use the button labeled "restore" as it has absolutely nothing to do with re-constructing a disk onto its replacement. 

It is actually a "Set Initial Disk Configuration" button. 

Pressing it immediately invalidates parity and would prevent any use of parity for reconstruction.

(There is an exception to this, but for now, assume there is not)

Should I pre-clear the new 2.0?

Yes, it will allow you to screen it for any early failures.  After being pre-cleared, it will still take as long to re-construct the old drive's re-constructed contents onto the new, but pre-clearing will let you deal with a defective drive before you swap out your old (smaller) working disk.

 

Joe L.

[lionelhutz]

Yup, power down, swap then and then power up. Click the "OK" check box and then the Start button and the rebuild will commence.

 

One nice thing about this swap is you still have the original disk with the intact data. If something goes wrong you can pull the data off that disk.

 

Peter

 

[zryder]

Thanks guys. I just finished a parity check just a few days ago, in anticipation of this swap.

in regard to pre-clearing, I can surely understand the need to test the new drive, but so long as I don't touch the data on the old drive untill everything is done, will it write 0's to the remaining sector's of the new disk, to verify that it is working, just as a pre-clear would do?

[Joe L.]

Thanks guys. I just finished a parity check just a few days ago, in anticipation of this swap.

in regard to pre-clearing, I can surely understand the need to test the new drive, but so long as I don't touch the data on the old drive untill everything is done, will it write 0's to the remaining sector's of the new disk, to verify that it is working, just as a pre-clear would do?

Yes, it will write the entire drive, filling the end with zeros as appropriate.  From what I understand, it actually expands the file system of the emulated drive first, then as it fills the replacement drive the zeros and/or file-system structures are copied into place.

 

The re-construction will not read the entire new drive back, so after rebuilding onto the new drive, you should run a parity check.

 

As you said, your old drive is your insurance until you know the new drive is working properly.

 

Joe L.

[zryder]

sounds good. Thanks for all your help!

 

I figured if nothing else, this is a "test" of the biggest feature of Unraid..

single disk failure data recovery.