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After backup: Destination is read-only?
I'm working on implementing a proper backup procedure as most experts on this forum recommend. But when trying to backup a large amount of data, I keep getting this error message:
Backup: Error backup job 'data to USB_HDD_4': destination is read-only.
The data, at first glance, seems to be copied to the USB drive.
I tried this on 3 different disks, 2 of which brand-new out of the box. So I don't believe they would all be faulty. This makes me think it is either a problem with my data on the NAS or a problem in the FrontView backup procedure.
When I connect the disk to the PC and remove directories manually, for some files with exteremely long names and a deep path, I get an error message "Source Path Too Long":
Therefore I'm currently suspecting very long file names and/or very long file paths, but I'm not sure if that is really what is causing this.
I removed some directories I suspected from the NAS, but in the next backup, the message keeps comming back. So now I'm stuck in a catch-22 situation. I'm not sure if my backup succeeds and don't want to remove any more data from the NAS, because it may not have been backed up properly. So I'm not able to implement a proper backup procedure at this time.
Has anyone found a root cause for the "Destination is read-only" message?
Is there any way that I can get more information on what went wrong during the backup (e.g. what file is causing the message)?
Backup: Error backup job 'data to USB_HDD_4': destination is read-only.
The data, at first glance, seems to be copied to the USB drive.
I tried this on 3 different disks, 2 of which brand-new out of the box. So I don't believe they would all be faulty. This makes me think it is either a problem with my data on the NAS or a problem in the FrontView backup procedure.
When I connect the disk to the PC and remove directories manually, for some files with exteremely long names and a deep path, I get an error message "Source Path Too Long":
Therefore I'm currently suspecting very long file names and/or very long file paths, but I'm not sure if that is really what is causing this.
I removed some directories I suspected from the NAS, but in the next backup, the message keeps comming back. So now I'm stuck in a catch-22 situation. I'm not sure if my backup succeeds and don't want to remove any more data from the NAS, because it may not have been backed up properly. So I'm not able to implement a proper backup procedure at this time.
Has anyone found a root cause for the "Destination is read-only" message?
Is there any way that I can get more information on what went wrong during the backup (e.g. what file is causing the message)?
Have been looking for a solution for this problem for a long time, but never managed to find the root cause.
In the end, I decided to remove the offending subdirectory that contained a file backup of a Windows system. This solved the problem with the backup procedure.
24 Replies
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- Hope it works for you, this is the scenario that fails every time for us. It's when you select the 'auto eject when done' that causes the problem, as the system can't gracefully unmount the drive, so causing the 'Read only' errors after x number of backups
Haven't used 'auto eject when done' and not planning to use it in the future. This is what I'm planning to do every two weeks:
1) Verify backup task is finished and status shows "Ready" or "Completed" (and not "In Progress").
2) Manually eject the first external backup drive.
3) Store it in a safe location.
4) Add the second external backup drive.
5) Verify the backup process runs on the next scheduled time.
During the two weeks I will just let the external drive on and attached to RN USB port. Since I don't have a high change rate on the data, I think this suites my needs.
- I had similar issues. I would format ntfs, do a backup (which appeared to be successful), and then subsequent ones would fail due to USB being read-only.
In a fit of rage, I formatted the USB drive as ext4. Problem went away. I can live with this. ncooper987 wrote: I will be curious as to what you find.
Have narrowed it down to 1 directory with several long files names. It contains 30 files and about 30% has file names over 128, but no longer then 133 characters. That is still way less than the 255 max length.#ls | awk '{ print length, $0 }' | sort -rn | head -1
133 .....
Also a long portion of these filenames is the same. The difference only occurs after about 100 characters.
Tried removing the hidden or archive flags and even the ACL, but that doesn't make any difference. Changed hidden files starting with . to names without dot. Doesn't make any difference either. Also the length of the path is not relevant to the problem. I now put the dir contents in \\NAS-XX-XX-XX\readydrop\metadata\plugins\org.eclipse.debug.core\launches, so nothing special I would say. I also tried to reduce the problem down to one file, but here's where it gets really strange.
If I remove a couple of files, the backup suddenly succeeds. But it doesn't matter which files are removed, as long as the total number of characters of all the filenames stays below 2112.
So I decided to keep all the files but reduce the number of characters in some filenames, so the total drops below the 2112 threshold.
Just adding 1 character to reach this threshold is the trigger point for the error "Destination is read-only" to occur. So 2112 produces the error, for 2111 characters the backup works.# ls -1 . | tr '\n' '\0' | xargs -0 -n 1 basename | wc -m
vs.
2112# ls -1 . | tr '\n' '\0' | xargs -0 -n 1 basename | wc -m
2111
But still not closer to a solution. Any thoughts, anyone?- I ran into this same things when I first got my hardware. It's cool that you are really diving into what the cause of the issue is. I will be curious as to what you find. The fix was to let windows fix the drive and format it to clear everything off. Then make sure that you enable ejection of the USB device after the last backup is performed. Then windows and the ReadyNAS are happier when you physically remove and re-attach drives. I have a 3rd backup performed by connected a USB drive to a specific USB and press the backup button. Once it's done the drive is disconnected. I then have an Email Rule to flag and notify me that backups are done. Otherwise all Readynas emails get filtered to a readynas folder that I review once in a while.
Good luck! - Followup:
mdgm wrote: Do you still have this issue if you connect the USB disk to the front USB port on the NAS?
Same message for the backup on USB 2 front port as I get on the USB 3 port on the rear of the RN: "Error backup job 'Documents to USB drive': destination is read-only." mdgm wrote: Can you send me your logs (see the Sending Logs) link in my sig?
Logs are in the mail.mdgm wrote: Do you still have this issue if you connect the USB disk to the front USB port on the NAS?
Hadn't tried that sofar. I intend to backup > 4TB to a USB 3 disk, so connecting it to the rear USB 3 port seemed the most logical thing to do. I am now trying a backup on the front USB 2 connector with the share that is causing the problems . But it may take quite some time to back it up on USB 2, as the share is quite big.
I made sure that dirs and files on the disk have no read-only nor archive flag set:F:\>Attrib -R -A /S /D
And chkdsk found no errors:F:\>chkdsk F:
Het type bestandssysteem is NTFS.
Het volume is in gebruik door een ander proces. Chkdsk
rapporteert mogelijk fouten ook als er geen beschadiging is.
Volumenaam is Disk1.
Waarschuwing. Parameter F niet opgegeven
CHKDSK wordt uitgevoerd in alleen-lezenmodus.
Bestanden controleren (stap 1 van 3)...
1332646 bestandsrecords verwerkt.
De bestandscontrole is voltooid.
0 records met grote bestanden verwerkt.
0 records met beschadigde bestanden verwerkt.
0 EA-records verwerkt.
0 reparserecords verwerkt.
Indices controleren (stap 2 van 3)...
1332806 indexvermeldingen verwerkt.
De indexcontrole voltooid.
0 niet-geïndexeerde bestanden gecontroleerd.
0 niet-geïndexeerde bestanden hersteld.
CHKDSK controleert de security descriptors (stap 3 van 3)...
1332646 bestands-SD's/-SID's verwerkt.
De controle van security descriptors is voltooid.
80 gegevensbestanden verwerkt.
Het bestandssysteem is gecontroleerd. Er zijn geen problemen vastgesteld.
5723132 MB totale schijfruimte.
310968 kB in 75 bestanden.
20 kB in 82 indexen.
0 kB in beschadigde sectoren.
5578976 kB in gebruik door het systeem.
Het logboekbestand neemt 65536 kB in beslag.
5717381 MB beschikbaar op schijf.
4096 bytes per cluster
1465122047 clusters in totaal op schijf
1463649556 clusters beschikbaar op schijf
By the way, the read-only checkbox in the Windows UI is a bit confusing, as explained here.- Can you send me your logs (see the Sending Logs) link in my sig?
Do you still have this issue if you connect the USB disk to the front USB port on the NAS? - Have narrowed it down to my "Documents" share that is causing the problem. All the other shares backup without issues. Will try to narrow it down further in the coming period.
If I connect the disk to the PC and look for files and dirs with read-only attribute set, it finds nothing. Strange. The NAS just told me there is a read-only problem.F:\>dir /A:R /R *.*
De volumenaam van station F is My Disk
Het volumenummer is XXXC-487P
Map van F:\
Het bestand is niet gevonden (= file not found)
If I check for dirty bit, it tells me the disk is clean.F:\>fsutil dirty query f:
Volume - f: is schoon (= f: is NOT dirty)
If I do a check disk on the drive, it tells me that no problems were found.
I had similar issues trying to back up a shared network drive to another netwrok drive that only I could see. After the initial backup it would ofcourse only update the changes. After a recent update to the newest software for the shared NAS the back up function stopped working.
"destination is read-only or files/folders could not be created. Check if these files or folders meet the destination file system limitation."
The destination is not read only. I unmounted the drives and hooked them up directly to my PC and scanned the file system with that.....blah blah blah. I tried a ton of different things before I finally just renamed the old back up folder and created a new empty one. The next backup then repopulated this new folder and everything works fine. Subsequent back ups have ran fine as well. I don't know if anyone else will find this helpful but it worked for me.
On a side note, I would be curious to hear an explanation for why this problem even occurred. Why would an update cause the system to erroneously identify a file as read only?
The status info stored on the drive includes a "dirty' bit, which usually ends up set if if the disk is not properly dismounted - esp. if a file copy was in progress when that was done.
If it is set (for whatever reason), the volume is mounted read-only by the NAS. On Windows, it results in a scan/repair prompt.
Clearing the dirty bit generally is only done as part of a scan/repair process that ensures the NTFS structures are ok. The NAS doesn't have the ability to do that, so you need to connect the drive to a system that can do it.
Your situation with the backup might have had a different cause of course.
Have been looking for a solution for this problem for a long time, but never managed to find the root cause.
In the end, I decided to remove the offending subdirectory that contained a file backup of a Windows system. This solved the problem with the backup procedure.
Sadly, I wish that was the case for our customers! We've now tried reformatting the backup drives as NTFS and HFS+ but the problem always comes back at some point.
Netgear still have problems using USB external drives and backup, which after nearly 2 years, needs fixing.
We've been having these issues since the original OS6 and it's only on NAS drives were the USB drive is unplugged after backing up.
We have a numbe rof customers who rotate between two or more USB backups and even when you select 'Eject after backup' every few weeks this problem occurs.
Customers with only one drive that is permenantly connected have never had this issue, so it's a bug in the software or hardware.
In most cases, if you mount the drive in a PC and let the OS "repair" it, the drive becomes readable again.
Usually what is happening is that the dirty bit is being set on the drive.
StephenB wrote: I still suspect the dirty bit somehow got set. If it happens again, try writing a file to the drive manually and see if that works. If it is mounted read-only then it will fail.
Yes, I'm not arguing that. But I would like to find the reason for the dirty bit to be set. If verified that all directories are read/write before I connect it to the NAS. Might be onto something with the long path and file names. Just started splitting up the backup, with one backup task for each share. Two smaller ones have succeeded sofar. I now scheduled the other shares, except the share where I suppect the long file names and paths reside. Will try to pin that down some more, if all the other shares have succeeded. Will take a while before everything is copied though, so more on that tommorow.StephenB wrote: USB backup is reasonably fast on the 516, but it should be just as fast to back up over a gigabit network. USB 3.0 would be faster over the network. Speeds are here: http://www.smallnetbuilder.com/nas/nas- ... l=&start=1
Would think so too, but can't achieve it in my setup. What would take 8 hours on a disk connected directly to the NAS, takes over 23 hours when copying over the network from the NAS to a USB disk on the PC. Can't really explain why this is so slow.- I still suspect the dirty bit somehow got set. If it happens again, try writing a file to the drive manually and see if that works. If it is mounted read-only then it will fail.
USB backup is reasonably fast on the 516, but it should be just as fast to back up over a gigabit network. USB 3.0 would be faster over the network. Speeds are here: http://www.smallnetbuilder.com/nas/nas- ... l=&start=1
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