Hello,

 

I have a failed drive that is not the parity drive that I will be replacing soon, currently my parity drive is a 2tb drive and the failed drive is also a 2tb drive.  I would like to take this opportunity to upgrade to a 3tb parity drive instead of a 2tb one. 

 

My assumption is that I have to replace the failed drive first if I replace a 2tb drive with a 3tb drive without having a 3tb parity drive can I eventually get the 3tb once I replace the parity drive after the failed drive has rebuilt.

 

Please let me know if I am missing something.

I would not upgrade your parity drive until you have a healthy array.

 

Once you have replaced the failed drive and run a parity check after rebuilding the drive, then I would upgrade your parity drive.

 

Good luck!

I would not upgrade your parity drive until you have a healthy array.

 

Once you have replaced the failed drive and run a parity check after rebuilding the drive, then I would upgrade your parity drive.

 

Good luck!

 

I understand what you are saying about replacing the failed drive and upgrading the parity drive are different steps.  What I want to avoid though is replacing my failed 2tb drive with another 2tb drive.  I would like to use the opportunity to buy 3tb drives instead.

 

Being that I have to replace my failed drive first I won't have a 3tb parity drive installed yet and will be replacing the failed disk with a larger disk. Are there any problems with this?

Parity has to be as big or bigger than your largest data disk.

Being that I have to replace my failed drive first I won't have a 3tb parity drive installed yet and will be replacing the failed disk with a larger disk. Are there any problems with this?

 

Yes -- you can't do it.    As noted, the parity drive must be >= all other drives in the system.

 

There IS a special procedure called "swap-disable" that will allow you to replace a failed disk with your current parity drive at the same time that you replace the parity disk with a new, larger disk.  This is outlined in the UnRAID manual ... I've copied the relevant portion here for your info:

 

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For swap-disable, you use your existing parity disk to replace the failed disk, and you install your new big disk as the parity disk:

1. Stop the array.

2. Power down the unit.

3. Replace the parity hard disk with a new bigger one.

4. Replace the failed hard disk with you old parity disk.

5. Power up the unit.

6. Start the array.

 

When you start the array, the system will first copy the parity information to the new parity disk, and then reconstruct the contents of the failed disk.

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Notwithstanding this feature, I do NOT generally recommend it, as if anything goes wrong with the parity copy, you have no fallback capability.  It is FAR better to replace your failed drive with the appropriate size drive;  and THEN upgrade your parity drive to a new, larger drive after you have a "healthy" array.

 

Also, I would NOT move from a 2TB to a 3TB parity drive.  With 6TB drives now available, I'd bump the parity disk to that level, so you have no future restrictions on what size drives you can use (at least not until drives > 6TB are available).    If that's a bit too pricey for you, at least go to 4TB for your parity.

 

I would like to replace a failed 3TB drive with my current  3TB parity drive and replace the parity drive at the same time with a new 4TB drive.

I can do that with the swap-disable method. I know this is risky, but I don't have another 3TB disk right now for the rebuild first....

 

What I would like to know is, I have a second, new, 4TB drive that I would like to add to the array. Should I add it when I am doing the swap-disable, or afterwards?

 

Both new disks are already precleared.

What I would like to know is, I have a second, new, 4TB drive that I would like to add to the array. Should I add it when I am doing the swap-disable, or afterwards?

You cannot add another disk at the same time as doing the swap disable.

As itimpi noted, you can't add a new drive while you're doing a swap-disable.

 

The safest approach is to simply pick up another 3TB drive, and do the drive replacement by itself;  then replace your parity drive; and then add your new 4TB drive.  You could also add your old parity drive as another data drive to gain even more capacity.

 

This sends shudders up my spine but I'm in literally the same boat.

 

Thinking 4-6 TB switched in for the parity, use the old parity to cover the dying 2 TB drive, pray the next drive to die is the 1 gigs lol

 

This sends shudders up my spine but I'm in literally the same boat.

 

Thinking 4-6 TB switched in for the parity, use the old parity to cover the dying 2 TB drive, pray the next drive to die is the 1 gigs lol

 

As long as you do it EXACTLY as noted in the UnRAID manual (which I quoted above), the swap-disable process works fine.    The reason I don't like it is if anything goes wrong with the parity copy, then you have no recourse [With a normal swap of the parity drive, you still have the old parity drive available].

 

In your case, I'd buy a new 2TB drive and replace your failed drive; THEN upgrade your parity to 4-6TB (I'd bite the bullet and go with 6TB so you don't have further size restrictions as you expand your array).    Relatively small (2TB) drives are very inexpensive these days -- even a high quality WD Red is only $90 [http://www.amazon.com/WD-Red-NAS-Hard-Drive/dp/B008JJLZ7G/ref=sr_1_2?ie=UTF8&qid=1408381683&sr=8-2&keywords=wd+red+drive ].

This is not that hard. Definitely wouldn't buy a new 2T!  Here is the strategy I have used:

 

1 - stop array and backup config directory on flash.

2 -.copy the data from the simulated disk to cache / other array disks / your workstation / external disk / new disk mounted outside the array or some combination.

3 - Then upgrade parity (doing a new config, adding your old parity as a new data disk). if you used a new disk in step 2 add that as a data disk too. Do not format the old parity

4 - If everything works and parity build successfully, format the old parity and copy everything to the newly formatted old parity.

5 - if something failed during the parity build you still have the old parity disk unaltered - you can restore the config backup and have restore options. If this happens suggest you post back for assistance.

If you have 2TB of available space to copy your data to, then I certainly agree with bjp999 => just backup the data from the failed disk (UnRAID will simulate it from the other disks and parity);  then you can just do a New Config with a larger parity drive;  do the parity sync;  run a parity check to confirm all is well;  and THEN add your old parity drive to the array as a new data drive, and copy the data back to it.

 

This assumes, of course, that you have 2TB of available space.    If you don't, however, you can buy a new larger drive to copy the data to -- so you won't have to limit yourself to a 2TB drive.

 

Note the nuance in my instructions. You ADD the old parity to the array in step 3, but don't FORMAT it till step 4. Having it in the array avoids a lengthy and unnecessary preclear.

 

I didn't say this, but you should not write to the array at all during step 3 - until the parity sync.is completed successfully.

So as bjp999 and garycase stated, I could plug one of my new 4TB drives into my MB. Then start the array, copy over the content of the simulated disk onto the 4TB which is not yet added to the array. And then follow bjp999´s instructions from 3 posts above this one.

 

Am i understanding this right?

I guess i create a mount point for the 4TB disk and then start to copy the content?!

So as bjp999 and garycase stated, I could plug one of my new 4TB drives into my MB. Then start the array, copy over the content of the simulated disk onto the 4TB which is not yet added to the array. And then follow bjp999´s instructions from 3 posts above this one.

 

Am i understanding this right?

I guess i create a mount point for the 4TB disk and then start to copy the content?!

 

You will have to format the disk. Perhaps the easiest way is to add it as your cache disk (replacing you current cache disk temporarily). UnRaid well then offer to format it. Click the format button (veeify this is the one and only disk showing as unformatted). Once done (1-2 minutes), you can stop the array again and put your cache back. Then you can mount the new 4TB.outside the array. Create a screen session. And enter the command "cp -Rpv /mnt/diskxx/* /mnt/temp". Where diskxx is your simulated disk and "/mnt/temp" is you mount point for the new disk. It will run a while but should create a copy of all of the contents.

Be cautious about copying it to any disk in the array (i.e. the cache disk).

 

I'm not certain whether or not this could trigger the "user share" bug that causes significant data loss, but I'd avoid doing anything that could even hint of that.

 

Personally, I'd attach your spare 4TB drive to a local PC, and just copy the data across the network.

 

Then reconstitute the array, and copy the data back across the network to the server.

 

... and THEN add the extra 4TB drive to  your server.

 

I'm assuming (based on the comments you've made on this) that you do NOT have backups of your data.    If you do, then it's much simpler -- just save a copy of the directory of the failed disk;  then do a New Config with your new parity and extra 4TB drive;  and then just copy the files that were on the failed disk back to the array from your backups.

 

The process I laid out of using the new 4T drive does not risk any issue with the user share copy bug.

 

Copying from the disk share to the cache disk would also not risk the user share copy bug. (Although the mover might try to move it back). Turning off user shares would be advisable IF this were the strategy (which it appears it is not).

 

The Windows approach would mean copying back and forth and other extra steps. But whatever he wants to do is fine. My approach is efficient and provides recoverability. Those are my primary goals.

So as bjp999 and garycase stated, I could plug one of my new 4TB drives into my MB. Then start the array, copy over the content of the simulated disk onto the 4TB which is not yet added to the array. And then follow bjp999´s instructions from 3 posts above this one.

 

Am i understanding this right?

I guess i create a mount point for the 4TB disk and then start to copy the content?!

 

You will have to format the disk. Perhaps the easiest way is to add it as your cache disk (replacing you current cache disk temporarily). UnRaid well then offer to format it. Click the format button (veeify this is the one and only disk showing as unformatted). Once done (1-2 minutes), you can stop the array again and put your cache back. Then you can mount the new 4TB.outside the array. Create a screen session. And enter the command "cp -Rpv /mnt/diskxx/* /mnt/temp". Where diskxx is your simulated disk and "/mnt/temp" is you mount point for the new disk. It will run a while but should create a copy of all of the contents.

Thank you for this detailed information. I will do it that way!

 

Gary, I rather do it bjp999's way. I disassembled my HTPC atm and other than that I only have a laptop at my flat....

That should work fine as long as you disable caching for all of your shares so there's no chance any top-level folder you copy to the cache will attempt to be moved to the array while you're doing the copies.

 

... and given that you don't have any other PC's to copy the data to, it's really your only option anyway 

 

I'm going to bite the bullet this week and order 2 6TB WD reds, might as well exapand the array if I'm going through this much pain.

 

Going to decide which method to follow as well, part of me thinks the failing drive is just about holding up and is readable, albeit at terribel speeds but it could save me an age.

Hi guys just wanted to check in. I, again, changed my procedure. My girlfriend had an external 3tb usb-drive I bought for her. She never really liked it because of the physical size and need for a power supply. So I bought her a 2tb 2,5 inch external, gutted the 3tb and am right now rebuilding my failed disk onto that one.

Next I will replace the 3tb parity disk with a new 4tb one and after parity building add another 4tb and the old 3tb parity disk to the array.

Luckily the failed 3tb is still under warranty and an RMA process has been started yesterday.

 

Seems all is good [emoji1]

 

Thanks again for the help!