N5200 Degraded Raid

[Patient]

My N5200 is setup as RAID 5 with 5 1TB hard disks (Seagate) - firmware 2.00.15.

Following a RAID expansion from 4 disks to 5 it went into "build" mode and I last saw it completed > 50.0% but don't know if it completed or not.

It now says the array is degraded and logs from last night said that Disk 5 had an I/O error (for some reason the logs are now empty!).

I keep a spare hard disk and swapped this for the "failed" disk but this made no difference so I swapped it back again - still the same.

In Raid config the only options not greyed out are "Remove Raid", "Back".

Could anyone please help - what should I do next?

[peterfu]

Put Your spare hard disc in and then mark it as spare if the rebuild process does not start automatically.
br
Peter

[Patient]

Put Your spare hard disc in and then mark it as spare if the rebuild process does not start automatically.
br
Peter

Thanks peterfu. Sorry for the delay but I felt the need to back-up before I went any further. I now have an Icy Box NAS4220 that I've backed up to (manually) - I hope to use rsync to do automatic backups but thats for later.

My system now tells me I have a healthy system but 25% (1 disk of a 5 disk RAID 5) of the data is "Unused". My RAID info page says:

Raid Level 5
Healthy
Disks Used 1,2,3,4,5
Total Capacity 3718.5 GB
Data Capacity 1487.2 GB / 2700.6 GB
USB Capacity N/A

My Disk info page says Total Capacity is 4,769,348 from 5 disks (though 1 Disk has a warning with 188 reallocated sectors).

I can find no way to allocate the unallocated space - any help gratefully received.

[peterfu]

Then You should do a "Space Allocation" or "Expansion"
br
Peter

[Patient]

Then You should do a "Space Allocation" or "Expansion"
br
Peter

Hi Peter

Thanks for the feedback - can't do a "Space Allocation". What does "Expansion" do? I thought I had already done this when I added the fifth disk! (used to be 4 disk RAID 5). Does "Expansion" prevent access during the "expand" (if so presumably for several days.

I'm currently running a "File System Check". It's been going for about 6 hours and gives no indication of how long its going to take. It is giving plenty of errors though (i_size should be 0, clead hdtree, i_blocks should be 0, index_fl flag set but not directory, etc).

[peterfu]

Adding a fifth disc tro the raid is a "Raid Migration" from a 4 disc RAID to a 5 disc RAID - now, if You want to use the available space YOu must do a "Expansion" - and then may be a "Space Allocation".

It's complicated, but gives You a little more flexibility.
br
Peter

[Funkstar]

It's complicated, but gives You a little more flexibility.

Very true. Because you might not want to use that space as part of the main RIAD volume. You might want it to be an iSCSI target or part of the USBCopy.

[Patient]

Hi petefu and Funkstar

Thanks for the heads-up.

Any idea how long (roughly) a file system check will take? - currently its at 9 hours (5 x 1TB RAID 5).

Does the RAID remain available during Expansion? If not how long (roughly) will it take (migration took 4 days!).

[Funkstar]

Yes it will remain available, but ptobably slower than normal.

I can't remember exactly. Though 4 days for a migration does sound a lot longer than I remember it taking. I seem to think about 36 hours, but I may be wrong.

[Patient]

Thanks Funkstar

My File System Check is now over 11 hours and shows no indication of slowing down - many many errors being fixed.

The reason I ran the File System Check is because I can no longer copy anything to the RAID via Samba or FTP, though I can delete. Also the N5200 says one of my folders is >300,000% bigger than its 500MB allocation.

Given that I've a File System Check underway that could last a week for all I know, this needs to be followed by an Expansion, and I've got a problem writing to the RAID that may not go away:

Would I be better to wipe the RAD and start again? How long will it take to create a new RAID 5 (1TB x 5 disks)? Any recommendations?

[Funkstar]

if i had everything backed up and could wipe it, then yeah, might not be a bad idea. Sounds like something is pretty messed up there.

[Patient]

if i had everything backed up and could wipe it, then yeah, might not be a bad idea. Sounds like something is pretty messed up there.

Thanks Funkstar

Is there a "best" way to wipe a RAID (eg formatting the hard disks)? or does a simple "Remove RAID" followed by "CREATE RAID" get the job done properly?

[Funkstar]

Remove then Create should do it.

I don't know if there is a better or recomended way though.

[peterfu]

And mix the drives during putting them back - so that every drive is on another place.

A filesystem check needs ages if many errors have to be fixed. So You might want to check each of Your drives with a check utility frpom the vendor before rebuilding the raid.

br
Peter

[Patient]

And mix the drives during putting them back - so that every drive is on another place.

A filesystem check needs ages if many errors have to be fixed. So You might want to check each of Your drives with a check utility frpom the vendor before rebuilding the raid.

br
Peter

Thanks Peter

As these are formatted ext3 and therefore can't be read by my PC would deleting the partitions do in place of filecheck? If not how can I use a check utility (Seagate Barracuda) from a PC (or cand the N5200 do it?)

[Funkstar]

Thanks Peter

As these are formatted ext3 and therefore can't be read by my PC would deleting the partitions do in place of filecheck? If not how can I use a check utility (Seagate Barracuda) from a PC (or cand the N5200 do it?)

Even when formatted with Ext3 Windows will see the drive is connected, just won't give you a drive letter and present the files to you. The Seagate tools will let you check the integrity regardless of filesystem, the tools go much lower level than that.

http://www.seagate.com/ww/v/index.js...00dd04090aRCRD