got an issue with my readynas shortly after the update to 6.2.5.
It doesnt seem to want to boot up properly. It seems to hang during "booting...." with the hard drive going (i left it over night in case it was running some fsck) and the power light flashing slowly.
I can ssh in - which is comforting.
I reboot it (shutdown -r ) - and it will start up and allow web logins - but I end up getting a "readonly filesystem" and cant save anything. Rebooting again - and its back to locking up with the flashing power light
Aug 25 09:05:37 ReadyNAS kernel: BTRFS error (device md125) in __btrfs_free_extent:5648: errno=-28 No space left Aug 25 09:05:37 ReadyNAS kernel: BTRFS info (device md125): forced readonly Aug 25 09:05:37 ReadyNAS kernel: BTRFS debug (device md125): run_one_delayed_ref returned -28 Aug 25 09:05:37 ReadyNAS kernel: BTRFS error (device md125) in btrfs_run_delayed_refs:2688: errno=-28 No space left Aug 25 09:05:37 ReadyNAS kernel: BTRFS error (device md125) in __btrfs_free_extent:5648: errno=-28 No space left Aug 25 09:05:37 ReadyNAS kernel: BTRFS debug (device md125): run_one_delayed_ref returned -28 Aug 25 09:05:37 ReadyNAS kernel: BTRFS error (device md125) in btrfs_run_delayed_refs:2688: errno=-28 No space left Aug 25 09:21:55 ReadyNAS kernel: usb 1-1: new high-speed USB device number 2 using ehci_marvell
even though there is space.
Also - mounting read-only does kind of limit the options to deleting stuff ? !
How do I fix this?
(And how the hell does it happen in the first place?)
I've tried to delete stuff - but then it goes readonly again - and when I reboot - the files I deleted are back.
(I tried a "sync" - didnt seem to make any difference)
There must be something better than wipe and restart ?
And - if I do wipe and restart - whats to stop it just doing it again in a few months???
Something is clearly messed up with the file system. It's possible that Netgear can go in and make some adjustments to fix it. But in my opinion doing the factory default on the current firmware is a more certain way to ensure its fully taken care of.
As far as preventing it in the future - that depends on exactly what happened. I haven't seen any issues with BTRFS for the 2 1/2 years I've been running it. Though my volumes don't get dangerously full, and I keep an eye on snapshot usage.
Do you have snapshots turned on? If so, are you running torrents or other applications that create a lot of churn?
I mentioned the problem in an earlier post but did not elaborate as it was getting quite late in the evening. The metadata is overfull.
The space on the volume is fully allocated so no further space can be allocated to metadata.
Doing a balance from the UI can help but as the metadata is overfull I don't think running a balance would work. If you want to try that backup your data first.
Your data volume has three layers and some of your disks are not on the compatibility list.
You could contact support and see if you can purchase assistance to attempt to fix this without a factory default but considering the complexity of this situation and your use of disks outside the compatibility list they may advise you to backup and factory reset the unit anyway.
You can schedule running a balance every few weeks or so (remember to schedule it when you are not actively using the NAS) in addition to filling your volume no more than 80-85% and that should help avoid running into a problem like this.
A balance moves data and metadata around so that chunks are emptied and then returned to unallocated space. If a balance finds a chunk that is already empty it will also return it to unallocated space.
metadata is data about data. BTRFS allocates space for system (not much is needed for this), data and metadata.
Sometimes if you say add a lot of large files and the volume becomes near fully allocated and then delete them and then add lots of small files too much has been allocated to data and there isn't enough free space to allocate more to metadata or vice versa.
We have changes coming which should alleviate this problem somewhat, however scheduling a regular balance is still recommended.
1) Its ok to run without any backup for a day or two - while you backup the backup, then reformat and restore the backup to the backup - nothing bad can happen during this time.
2) Its ok for the unit to lock up if you fill it more than 80-85% full, and the only way to fix it (without doing a 2nd backup) - is to pay for support to dial in...
