[SOLVED] Replacing 4 old 1.5 TB Drives with 2 4TB Drives - Advice Needed

[damelon]

I have 4 old 1.5TB Drives that are hitting the age wall and starting to get enough reallocated sectors that I want to remove them from my array.    I have 2 4TB Drives that I would like to replace the old ones with.    I've read about upgrading one drive with a bigger one, or "shrinking" the disk count of the array, but I'm not sure what approach I should take, but since it is not a 1-1 replacement, I'm not sure that just a direct "replace" is the way to go here.

 

I'm guessing the solution would be to add the new disks to the array, and use MC to move contents of the 4 disks in question to the new disks, then remove the 4 old disks from the array, but I'm not sure what the optimal process would be, or the safest. 

 

Also, if I use MC, can you select multiple root share folders at once to move? Like /Movies, /Tv, /Music  Can I select these 3 roots and move them to the new drive or would it have conflict issues.

 

I'm just looking for some good step by step advice if anyone can provide it. 

 

Thanks!

[limawaken]

I'm still quite new to all this, but I am interested to learn how you do this.

 

I think you should swap out your parity drive first since parity drive should be as big as the largest drive in your array. Do you have parity drive?

Not sure about how to reduce disk count, but your idea about using MC to move the contents sounds  right.

You then should be able to remove the old drives. There's a guide on how to do that - http://lime-technology.com/wiki/index.php/FAQ#How_do_I_remove_multiple_drives.3F

 

This wiki guide seems to be pretty clear -

http://lime-technology.com/wiki/index.php/Shrink_array

[damelon]

I'm still quite new to all this, but I am interested to learn how you do this.

 

I think you should swap out your parity drive first since parity drive should be as big as the largest drive in your array. Do you have parity drive?

Not sure about how to reduce disk count, but your idea about using MC to move the contents sounds  right.

You then should be able to remove the old drives. There's a guide on how to do that - http://lime-technology.com/wiki/index.php/FAQ#How_do_I_remove_multiple_drives.3F

 

This wiki guide seems to be pretty clear -

http://lime-technology.com/wiki/index.php/Shrink_array

 

Yeah my parity drive is already a 4TB drive, so I don't need to do that.  I've read that shrink guide, but wasn't sure if people would recommend that I do a "Replace" with 2 drives and then move files shrink the other two, or add the two new drives, move files from the 4 old drives, then shrink all 4, or maybe another method.  Most examples use 1 drive so wasn't quite sure if there was a better way to do it in a case like this

[JonathanM]

Safest would probably be to preclear the 2 new drives, add them to the array, copy the contents, verify the copy, remove the old drives, set new config and recalc parity. If you make a full backup of your flash drive before you add the new drives, you could always revert back to that config if you have a drive failure mid process and need to rebuild instead of copy.

 

Before you start anything, pull smart reports on all drives after a full non-correcting parity check that returns with no errors. If anything hinky shows up, address that before proceeding.

[garycase]

Since you already have a 4TB parity drive, I'd simply do the following ...

 

(0)  Before you really start, preclear the 4TB drives just to confirm they're good.    You want to discover any "infant mortality" issues BEFORE they're part of your array      Also do a parity check before you start, to confirm all is well with the array before you begin modifying it.

 

(1)  Copy the complete contents of your flash drive to a folder on a client PC (It's always a good idea to have a reasonably current backup of this anyway)

 

(2)  Stop the array and assign one of the 4TB drives in place of one of the smaller drives.  Now just Start the array and let it rebuild the drive onto the 4TB unit.

 

(3)  Do a parity check to confirm all went well in the rebuild.

 

(4)  Repeat Steps (2) & (3) for the 2nd 4TB drive and another one of the smaller drives.

 

(5)  Now, if you want to, you can just copy the contents of the remaining 1.5TB drives to the new drives.  There's really no need to do that -- you could simply replace them with larger drives as well over the next few months ... if one should actually fail, you can then either replace it or simply copy its contents to another drive (you'll still be able to read it, since the data will be reconstructed by UnRAID).

 

[damelon]

Since you already have a 4TB parity drive, I'd simply do the following ...

 

(0)  Before you really start, preclear the 4TB drives just to confirm they're good.    You want to discover any "infant mortality" issues BEFORE they're part of your array      Also do a parity check before you start, to confirm all is well with the array before you begin modifying it.

 

(1)  Copy the complete contents of your flash drive to a folder on a client PC (It's always a good idea to have a reasonably current backup of this anyway)

 

(2)  Stop the array and assign one of the 4TB drives in place of one of the smaller drives.  Now just Start the array and let it rebuild the drive onto the 4TB unit.

 

(3)  Do a parity check to confirm all went well in the rebuild.

 

(4)  Repeat Steps (2) & (3) for the 2nd 4TB drive and another one of the smaller drives.

 

(5)  Now, if you want to, you can just copy the contents of the remaining 1.5TB drives to the new drives.  There's really no need to do that -- you could simply replace them with larger drives as well over the next few months ... if one should actually fail, you can then either replace it or simply copy its contents to another drive (you'll still be able to read it, since the data will be reconstructed by UnRAID).

 

Thanks.  I had already done 0 & 1.  I think this is the way to go, 2 of my drives had quite a few reallocated sectors where the other 2 did not have many at all.  I think they can last a month or two until I see another hard drive sale.

 

Just started #2 and rebuild in progress on that disk.   

[damelon]

Just a followup.  I ended up getting 4 new hard drives based on what was on sale.  (2 3tb and 2 4tb) - Basically just did replaces on each drive after a pre-clear.  All is well!  Seemed the easiest way to do it.

[garycase]

Indeed that was the easiest approach, as you didn't have to modify your config -- just replace the 4 drives (one at-a-time).    And you now have an extra 8TB of space