I replaced a failing 1TB drive with a new 4TB.  I'd already pre-cleared the new drive. Using unMenu, I formatted the drive, stopped the array, replaced the old drive in the array with the new one, leaving the old drive attached, but unassigned, then restarted the array.

 

It comes up with a red-ball now. 

 

I was able to move all the data off the old drive before it went bad. Is unRaid still going to try to 'rebuild' all the nonexistent data on the drive and leave it red until it's done?

 

Syslog attached

 

EDIT: Bouncing between Dynamix and unMenu... I've got the following screenshot from Dynamix stating that the array will be unprotected if I start it.  Why would that be - all my drives are assigned properly, including parity.

syslog_2014.12.26.zip

I haven't looked at the syslog yet, but just from your statements of what you did, I can see a very regrettable action.  Please don't kick yourself too hard, but you should NOT have formatted that drive!  By formatting it, you have added a file system to it, which is essentially a bunch of data, and thereby completely canceled the Preclear!  UnRAID needs a completely clear (totally zeroed) drive before it can add it to a parity protected system.  It either has to be Precleared, which writes zeroes to the entire drive plus a first partition and a hidden signature in the unused initial blocks of the drive, or UnRAID itself will have to clear the drive before adding it.  UnRAID will do the formatting itself, while updating parity for it.  UnRAID cannot use a drive you have prepared because parity would be all wrong.  It would have to rebuild the entire parity drive instead.

so... I need to re-preclear it.    crud.

 

Since I know that drive 5 was empty, what's the best course of action to remove all physical drives from the drive 5 slot so I can bring the array back up while the preclear is running?

so... I need to re-preclear it.    crud.

There's a Preclear option (-n) that will allow you to skip the preread and postread, making it much faster.  It will still do the zeroing and prepping of the drive, marking it as Precleared.

 

Since I know that drive 5 was empty, what's the best course of action to remove all physical drives from the drive 5 slot so I can bring the array back up while the preclear is running?

I'm not completely certain, because I took a look at your syslog, and the system appeared to be confused by the new Disk 5.  It's not just that it found a file system on it, but that the size is 4tb, when it knows that the simulated Disk 5 is 1tb.  It normally rebuilds the old disk onto the new disk, then expands the file system to fit the new size.

 

I'm afraid Disk 5 is not empty, even if you deleted every file and folder on it.  The contents of those files are still there, and parity depends on the existence of the original Disk 5, exactly as it last saw it, including all of the deleted content.  As I'm sure you know, deleting a file does not change the disk sectors containing the content of the file.  It just updates the folder directory to mark the file as deleted, and releases all of the disk sectors for reuse.  To completely remove Disk 5, you will have to unassign it, then rebuild parity anew.  Sorry!  Or you can Preclear the new drive again, assign it to Disk 5 (assuming the system can forget the added new drive and only remember the old Disk 5), then let it rebuild the old Disk 5 onto the new drive.  Whatever you do, don't format or modify that drive once it's Precleared!  Just assign it and let UnRAID take care of preparing it.

Not ideal, but not fatal.

 

preclear -n is running.

 

Thanks, RobJ

OK, 18 hours (and a movie at the theater) later, it's finished the preclear. I reassigned the drive to the array & started it, but it's still showing red.

 

Syslog attached. Oddly, it seems to end in the middle of a line at 05:59 today. Current time is 19:55 EST. Not sure what's up with that...

 

Next step?

syslog-20141227-1946.zip

Show a screenshot of unRAID main. Does the syslog continue?

Great question - unfortunately, it stops then, too...

OK, 18 hours (and a movie at the theater) later, it's finished the preclear. I reassigned the drive to the array & started it, but it's still showing red.

 

Syslog attached. Oddly, it seems to end in the middle of a line at 05:59 today. Current time is 19:55 EST. Not sure what's up with that...

 

Next step?

 

That's just a 2 minute piece of the syslog, abrupt start and abrupt end.  Looks to me as if the system crashed at least partly, and the syslog agent is no longer running.

 

That 2 minute piece does not show Disk 5 was ever assigned.  Since something has gone seriously wrong, I'm not sure you can trust a red ball indication.  I *think* it should be blue(?) to indicate a new drive, and then after clicking the Start Array button, offer to rebuild Disk 5.  If not, and that formatted disk may have confused the state of Disk 5, then you may want to unassign the parity disk, add the new Disk 5 and let it be formatted (should be quick), then stop and re-assign the parity drive and let parity be rebuilt, all past Disk 5 bits forgotten forever.

Scanning through this thread, I think there's a bit of misunderstanding ...

 

First, pre-clearing a drive does NOTHING to make replacing a failed drive any faster.    A pre-cleared drive is only "quick" if you're ADDING it to the array ... not if you're just replacing another drive.  In that case, pre-clearing is simply a good test of the drive -- otherwise it's irrelevant.  It also didn't matter that you had formatted it -- it was still going to be rebuilt.

 

Second, since you REPLACED a drive, then Yes, UnRAID is going to rebuild the data from the failed drive onto the new drive, even if the "data" is all empty space.

 

From what you've outlined, I don't THINK you have destroyed parity, so the new drive will in fact be built to match the old (failed) drive.    But another alternative is to simply do a New Config and let it do a new parity sync altogether.    What you'll lose by doing that is the ability to rebuild the old drive; but since there's nothing on it that you need that's not relevant in this case.    The time to do a rebuild is probably about the same as a new parity sync, so it doesn't make a lot of difference which you choose to do.

 

 

I did restart the array but got no offer to rebuild disk 5.

 

As I understand it, these are my steps:

stop the array

Unassign the parity drive

leave disk 5 assigned as is (since it is started with the new disk 5)

start the array w/o parity

stop the array

reassign parity

start the array

let parity rebuild

 

With confirmation, I'll get this kicked off.

 

Thanks again for your help, guys!

You had already gone a bit too far to maintain good parity, so there wasn't any option to do a rebuild.

 

What you should do now is a "New Config" (on the Utils tab) -- assign all of your data drives AND your parity drive;  then simply start the array and it will do a new parity sync.

 

Thanks, Gary.

 

I've done this, and now it's offering to format the drive as parity rebuilds. Do I want to allow this now as Rob suggested in his most recent post? If I don't, I believe the offer to format will remain, and I haven't seen that in my last several months of normal operation.

 

EDIT: I did already start the array and the parity rebuild is running...

I'd wait for the parity sync to complete; then do the format.    Formatting now will cause a bunch of unnecessary "thrashing" head movement on both the new drive and the parity drive.    The format will only take a couple minutes if you simply wait and do it after the sync is complete.

 

Will do, and thanks again!

 

This is my first drive replacement, all the rest have been array expansions. I thought it was going to be smooth sailing, I guess I should have read the directions a bit more clearly before I started.

Just remember that a pre-clear doesn't help with the time for a replacement ... it's still a good idea as a thorough test of the drive, but it's irrelevant what the content of the drive is when you're going to use it as a replacement.

 

The simplest replacement process is:  (a) Stop the array and unassign the drive to be replaced;  (b) Start the array so it shows a missing drive;  © Stop the array and assign the new (replacement) drive to the slot where the drive was missing [This may require an actual shutdown if you need to physically do the drive replacement at this point];  (d) Start the array and wait while UnRAID rebuilds the drive.

 

I ran three passes of pre-clear, then ended up with a fourth pass fixing my mistake. I'm comfortable that the disk is good, and I'm sure I didn't save any time!

As I noted earlier, the 4th pass didn't "fix your mistake" => the drive could have simply been used as it was for a replacement.    Same is true when you do a New Config.    The ONLY time a pre-clear signature is helpful is if you're ADDING a drive to a protected array and don't want to require a full clear by UnRAID.

 

so... the final preclear -n wasn't necessary to remove the formatting?

 

In either case, the server is back up and running, thanks Rob & Gary for your help!

so... the final preclear -n wasn't necessary to remove the formatting?

 

In either case, the server is back up and running, thanks Rob & Gary for your help!

A drive that is cleared or precleared already matches parity, so when you add it to a protected array, nothing else needs to happen for the array to be protected.

 

When you replace a drive, it will be rebuilt from parity and so its previous contents are replaced and it is made to match parity. Doesn't matter what was on the drive before. So clearing doesn't matter.

 

When you do a new config, parity is recalculated to match all the other drives in the array. Doesn't matter what is on those drives so clearing a drive in a new config doesn't matter.