To Upgrade or Not?

[Mopar_Mudder]

My server runs so perfect that I really don't follow the upgrades and such that UnRaid has made. I am running version 5.0.3 and my array if full, so I can't add more drives. So I have two Seagate 4 TB NAS drives on the way that I need to put in my array. One will go to Parity replacing the  current 3TB drive, the other will replace a 1.5TB drive in the array and the existing  3TB parity drive will replace another 1.5TB drive.

 

I have no open slots so I can't preclear the drives. Is their any good reason for me to go to version 6 before doing all of this? I guess mainly any speed improvements while adding the drives, I am guessing it is going to me a slow process.

[garycase]

My server runs so perfect that I really don't follow the upgrades and such that UnRaid has made  ....

...  Is their any good reason for me to go to version 6 before doing all of this?

 

No.  If you're happy with the server's performance, and don't have any compelling need for the features added by v6 (Dockers and VMs), I'd simply leave the configuration ALMOST as it.    I say "almost", because I WOULD update your bzroot and bzimage files to v5.0.6 so you're running the final stable version of v5.

 

 

So I have two Seagate 4 TB NAS drives on the way that I need to put in my array. One will go to Parity replacing the  current 3TB drive, the other will replace a 1.5TB drive in the array and the existing  3TB parity drive will replace another 1.5TB drive.

 

Clearly this will take a while.  As I assume you know, the first thing you should do is run a current correcting parity check to ensure the array is error-free.    If any sync errors are found and corrected, do it again -- you want ZERO sync errors and ZERO disk errors before you proceed.

 

Next, replace the parity drive, and wait for the array to finish rebuilding parity to the new drive.    Then run another parity check to confirm that went well (there are no write confirmations during the rebuild).

 

Next, stop the array; unassign the 1.5TB drive you want to replace with the other 4TB drive; Start the array so that drive is shown as missing;  Shut Down and physically replace the drive with the new 4TB drive;  then boot; assign the 4TB drive to the "missing" drive slot; and Start the array and let it do the rebuild of that drive.    When it's done, do yet-another parity check to confirm that rebuild also went well.

 

Finally, you can repeat the process in the previous paragraph to replace the remaining 1.5TB drive you're updating with the old parity drive.

 

 

I have no open slots so I can't preclear the drives.

 

That's a bit of a risk, but being certain you do all the parity checks I noted will give you fairly high confidence in the integrity of the drives.    I'm assuming you don't have another system you could use to do the pre-clears.

 

There IS a way you could pre-clear the drives; but it would add a significant amount of downtime to your array.  If you prepare a spare USB flash drive with UnRAID (the free version) and a copy of the pre-clear script; you could shut down the system;  unplug two of your drives and plug the 2 new 4TB drives in their place;  then boot to the new UnRAID flash drive (be SURE you don't boot to your normal flash drive);  and then pre-clear those two drives.    If you do this, be CERTAIN you're pre-clearing the correct 2 drives (MAJOR Catastrophe if you pre-clear one of your current array drives).

 

That would let you pre-clear the new 4TB drives; but the array will clearly be unavailable during the entire pre-clear (a couple days for 4TB units).    Then, when the pre-clears are done; replace the original drives in their place; boot the array; and follow the procedure I outlined earlier (starting with a current parity check).

 

After you've got the two new 4TB drives installed in the system, you could also pre-clear your old parity in a similar way.  Unplug one drive from the system and plug the old parity drive in its place;  boot to the NEW USB flash drive you made just for pre-clears; and pre-clear the old parity drive.  As before, be CERTAIN you pre-clear the correct drive.  When done, shut down; replace the drive you temporarily unplugged;  and then follow the steps for replacing the final 1.5TB drive with the old parity.

 

The BEST way to pre-clear the drives would be to use a 2nd USB flash drive (as I outlined above: BUT to use a different system for the pre-clears; so there was no impact on your array while the drives were being pre-cleared.

 

Note, by the way, that pre-clearing the drives is purely a confidence test in this case -- it will not save ANY time during the rebuilds.  The pre-clear signature only saves time if you're adding a NEW drive to the system ... not when you're upgrading a previous unit.

 

 

[Mopar_Mudder]

thanks for all the info, that was great.

 

I do have an old server that I haven't run in years. One of the reasons that I stopped using it is because it has to boot from a floppy and it always worried me with the reliability of floppies. I suppose I could try and fire it up and see if it will run to do the preclear, I will consider it.

 

Is their any sort of chart out their with the different versions of Unraid and what features are different between them. If not it would be a nice thing to have.