Running 5.0.3

 

I replaced 2 drives at once and started my array - instead of the normal 'rebuilding' notice i got the 'unformatted disks' notice. I then put back in the one of the 2 old  disks, but now the array will not start and says "replacement disks too small error". I then unassign it and start the array. The other disk upgraded disk shows up as unformatted, and is not rebuilding.

 

How do I get back to where rebuilding the array?

 

Thanks

Running 5.0.3

 

I replaced 2 drives at once and started my array - instead of the normal 'rebuilding' notice i got the 'unformatted disks' notice. I then put back in the one of the 2 old  disks, but now the array will not start and says "replacement disks too small error". I then unassign it and start the array. The other disk upgraded disk shows up as unformatted, and is not rebuilding.

 

How do I get back to where rebuilding the array?

You can never upgrade two disks at once!  You have to do them one at a time and let the rebuild onto the upgrade disk complete before starting the second one.

 

From what you have said you do not think you currently have a failing disk?  Assuming that is correct then at this point I would think that your best chance is to make sure you know what all your disk assignments should be (making a note of the relevant serial numbers for each disk); do a 'New config' from the Tools menu; and reassign all drives.  I am not sure whether it would be better to tick the 'trust parity' box as it could well be invalid by now if any of your previous actions caused a change to be written, but it might be OK if you promptly run a correcting parity check on restarting the array to fix any such issues.  When you start the array then all the disks should come up as good and all your files be present- if not then you have a serious risk of data loss if you do not have good backups.

 

You might want to wait a bit before doing the above in case anyone can suggest a better way forward.

Yes, I would say try to put back all of the original disks and do New Config. Make very sure you know which disk should be assigned to which slot, especially the parity and cache drives. I think parity should be OK but I would do a correcting parity check anyway. Double check all connections so you don't get a failure due to connection issues. Don't even try to do anything else until you have successfully done this and reported back.

 

Understanding how parity works would have made it obvious that unRAID can only rebuild one disk at a time, since ALL of the other disks are required to do a rebuild. Please try to understand this and it will help keep you from making similar mistakes in the future.

 

Thanks everyone,

 

the crazy thing is...I had done 3 disks previously (one at a time), and tried to do the last two together. The array is rejecting the smaller disk now since I started the array, so i've put both larger disks in and its started. It says data rebuild in process, I just dont know for which disk. Either way i have the old disks, non is failing so I'll copy the data back somehow

 

Is there a method for this?

Did you test your new disks with preclear?

 

I'm a little concerned that you don't know which disk is rebuilding. Post a screenshot.

 

Clearly you can NOT replace more than one drive at a time.  It requires ALL of the other disks plus parity to reconstruct the data for the replacement disk.

 

Your best bet at this point, IF both of the disks you replaced were good and you were just doing this to increase the size, is to do a New Config with the ORIGINAL disks;  let the parity sync run to rebuild your parity disk;  then do a parity check to confirm all went well;  and then replace ONE disk at a time with the new, larger disks.

 

I have to agree with garycase. If it is rebuilding one disk, but two of the original disks aren't there, then whatever disk it is rebuilding is going to be wrong, since it will be rebuilding against the other new disk, which doesn't have the correct data on it.

 

Suggest you stop and New Config with the old disks. Remove the new disks completely, and make very sure you assign the parity disk correctly when you do the New Config. If you accidentally assign a data disk to the parity slot unRAID will overwrite that data with parity.

 

Your description of what is going on is not completely clear, so if you think we are not describing your situation correctly, then post a screenshot.

Here is where I am as of this morning...I'll wait to hear back before doing the new config. It doesnt look like it rebuilt either disk.

 

It may have rebuilt one of them, but since it would have been a bad rebuild you probably couldn't tell.

 

Are the 2 unformatted drives the new ones?

yes, both, and I can see the shares are not there on either, so the rebuild is bad.

 

Please point/walk me through the New Config process.

 

I think what happened is that after I added the two new disks, I started the array.It accepted them as unformatted. I then figured I did something wrong and tried to replace the old disks but without doing a new config. the system rejected the attempt to replace the now new 4 TB disk with old 750 GB disk citing "disk too small" etc.

 

Thanks all

 

 

Shut down and replace the 2 new drives with the 2 original drives. Double check all connections. When you boot up unRAID will not let you start the array because you have changed the configuration. Go to Tools - New Config and it will forget about the configuration. Then you can set a new configuration with the disks that are in your server, including the original disks from when you tried to replace 2 at once.

 

Be sure to assign all the disks to their correct slots. Most important that you assign parity correctly. If you accidentally assign a data disk to parity it will be overwritten with parity. Before you start the array, make sure none of the disks say unformatted. If they do, don't start and report back.

 

OP - can you give some insight into why you thought that you could replace 2 disks at once?

 

UnRAID protects against a single disk failure. Using the same mechanism, can upsize a single disk (unRAID thinks the old disk failed and it is rebuilding it).

 

Suggest you study the link that trurl posted about what parity is and how unRAID protects your array. It would help avoid problems like this in the future.

 

 

foraye ==> Before doing ANYTHING else, answer a couple of questions:

 

(1)  Had EITHER of the disks you replaced failed?  (I assume the answer is no)

 

(2)  Have you done ANYTHING that would WRITE to the array since starting this process?    [Not counting writes to the 2 new disks ... i.e. did you write any new files; modify anything on the array; etc.]

 

If the answer to #1 is Yes, and #2 is No, then it MAY be possible to recover the data if only ONE of the disks had failed.    If the answer to #1 is No, then you should simply do as I suggested earlier, and trurl just outlined for you ... i.e. a New Config with the ORIGINAL disks.

 

Note there is an alternative approach you could take if both disks are good AND you have another system you could attach them to.    You could do a New Config with the two NEW disks; do the parity sync; then format the two new drives; and then copy the data from the two old drives to the array by attaching them to another system and simply copying the data to UnRAID  [Or you could attach them to available SATA ports on your server and copy them locally; but that requires using Linux command line utilities you may not feel comfortable with.].

 

 

foraye ==> Before doing ANYTHING else, answer a couple of questions:

 

(1)  Had EITHER of the disks you replaced failed?  (I assume the answer is no)

 

(2)  Have you done ANYTHING that would WRITE to the array since starting this process?    [Not counting writes to the 2 new disks ... i.e. did you write any new files; modify anything on the array; etc.]

 

The answer to both is NO.

 

 

OP - can you give some insight into why you thought that you could replace 2 disks at once?

 

UnRAID protects against a single disk failure. Using the same mechanism, can upsize a single disk (unRAID thinks the old disk failed and it is rebuilding it).

 

Suggest you study the link that trurl posted about what parity is and how unRAID protects your array. It would help avoid problems like this in the future.

 

Thanks...will do!

Thanks Everyone...rebuilding Parity with the old drives...As it turns out the dropdown listbox for assigning disks had them all in order, but went through just to make sure. I'll then swap them ONE AT A TIME!

 

I've basically added five 4TB disks and another 2TB I had sitting around for 2 years or so. I'll definitely take some time to understand the system better.

 

 

 

Thanks Everyone...rebuilding Parity with the old drives...As it turns out the dropdown listbox for assigning disks had them all in order, but went through just to make sure. I'll then swap them ONE AT A TIME!

After parity is built, you need to do a parity check, to make sure the parity drive reads back what was written. Then you can be confident that a rebuild using that data will succeed.

Agree r.e. a parity check.  The parity sync does NOT do a verify, so you'll want to do a parity check to confirm all is well before you depend on the system to rebuild your disks.

 

So just have patience while the sync, and then check, gets done.    Then you can swap the new disks ONE AT A TIME and let them rebuild 

Then on to the upgrade to 6.0...

Then on to the upgrade to 6.0...

Patience

 

Have you read the upgrade guide?

Definitely agree ... at this point what you need is patience 

 

~ 10 hours for the parity sync

 

... then ~ 10 hours for a parity check

 

... then ~ 10 hours to do a rebuild

 

... then ~ 10 hours for another parity check (should do that to confirm the rebuild went well)

 

... then ~ 10 hours for the 2nd rebuild

 

... then ~ 10 hours for yet-another parity check (to confirm that one also went well)

 

... then DONE  8)

 

THEN it's time for the v6 upgrade.

 

Meanwhile ... that gives you plenty of time to read through the upgrade guide  :)