Re: Filesystem full errors when there is plenty of space?

Hello Derek,

Hard to tell with the information you provided, but this error might be 
caused by the following reasons:

 1.

    *Not enough disk space at destination* (this doesn't seem to be your
    case, as you have ~25TB free on /mnt/backup/)

 2.

    *Not enough inodes at destination*. You can check with:

    |df -i /mnt/backup/ |

    Note that encfs filesystems can sometimes have inode limitations
    inherited from the underlying filesystem, so also check:

    |df -i / |

    (or whatever filesystem underlies your encfs mount)

 3.

    *Not enough disk space or inodes in your TEMP folder*. rdiff-backup
    may write temporary files to the system's temp directory (typically
    |/tmp|) during regression/restore operations. You can check with:

    |df /tmp df -i /tmp |

    With only ~8GB free on your |/| filesystem (which likely also hosts
    |/tmp|), this could very well be the culprit, especially during a
    regression pass which involves reconstructing files by applying
    rdiff patches.

Given your traceback, the error is happening during a *regression* 
(rolling back a previously failed backup), which involves reconstructing 
and writing out full file contents as temporary files. This can require 
significant temporary space depending on the size of the files being 
reconstructed.

My best guess given your numbers is *option 3* — the 8GB free on your 
backup server's root filesystem may not be sufficient for the temporary 
files being written during regression.


On 5/5/26 08:52, Derek Atkins wrote:
> Hi
>
> I've suddenly, recently, starting getting "File System Full" errors from the backup of one of my servers. This particular server 
> is still using 1.2.8. What I don't know is: what filesystem is full? 
> There is plenty of space on the system being backed up: [root@ovirt-0 
> ~]# df . Filesystem 1K-blocks Used Available Use% Mounted on 
> /dev/mapper/centos--ovirt--0-root 209608708 107709568 101899140 52% / 
> And there is plenty of space in the filesystem where the backup is 
> being saved: [backup@backup ~]$ df /mnt/backup/ Filesystem 1K-blocks 
> Used Available Use% Mounted on encfs 27143488384 1224301312 
> 25919187072 5% /mnt/backup Is the issue the space in the CWD of the 
> backup server? I've only got 8G free in CWD there: [backup@backup ~]$ 
> df . Filesystem 1K-blocks Used Available Use% Mounted on 
> /dev/mapper/fedora_backup-root 15718400 6388680 9329720 41% / 
> Unfortunately the backtrace does not tell me what file is being 
> written when it runs out of space, so I don't know what to "fix".  Also, due to
> "reasons" I cannot upgrade -- but I am happy to hot-patch if there is a
> simple way to add the target that is failing.
>
> I'd appreciate any guidance.
>
> Thanks,
>
> -derek
>
> Backup Command and output:
>
> *** Starting backup for ovirt-0 at Tue 05 May 2026 06:44:21 AM EDT
> /usr/bin/rdiff-backup-1 --exclude /mnt/snap/dev --exclude
> /mnt/snap/lost+found
> --exclude /mnt/snap/media --exclude /mnt/snap/mnt --exclude /mnt/snap/proc
> --exclude
> /mnt/snap/run --exclude /mnt/snap/sys --exclude /mnt/snap//ovirt --exclude
> /mnt/snap//rhev --include /mnt/snap//var/lib/ovirt-hosted-engine-setup/
> --include
> /mnt/snap//var/lib/ovirt-hosted-engine-ha/ --include /mnt/snap//var/lib/mysql
> --include /mnt/snap//var/lib/vdsm --include /mnt/snap/var/spool/cron
> --include
> /mnt/snap/usr/local --exclude /mnt/snap/bin --exclude /mnt/snap/lib --exclude
> /mnt/snap/lib64 --exclude /mnt/snap/sbin --exclude /mnt/snap/tmp --exclude
> /mnt/snap/usr --exclude /mnt/snap/var ovirt-0_backup::/mnt/snap/
> /mnt/backup/backups/ovirt-0
> File descriptor 3 (socket:[104543988]) leaked on lvcreate invocation.
> Parent PID
> 13337: /bin/bash
>    Logical volume "snap" created.
> Previous backup seems to have failed, regressing destination now.
> Exception '[Errno 28] No space left on device' raised of class '<type
> 'exceptions.IOError'>':
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/robust.py", line
> 32, in
> check_common_error
>      try: return function(*args)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/restore.py", line
> 468, in
> get_fp
>      Rdiff.write_patched_fp(current_fp, delta_fp, new_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Rdiff.py", line
> 73, in
> write_patched_fp
>      rpath.copyfileobj(librsync.PatchedFile(basis_fp, delta_fp), out_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/rpath.py", line
> 64, in
> copyfileobj
>      outputfp.write(inbuf)
>
> Exception '[Errno 28] No space left on device' raised of class '<type
> 'exceptions.IOError'>':
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 304, in
> error_check_Main
>      try: Main(arglist)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 324, in Main
>      take_action(rps)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 280, in
> take_action
>      elif action == "backup": Backup(rps[0], rps[1])
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 337, in Backup
>      backup_final_init(rpout)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 501, in
> backup_final_init
>      checkdest_if_necessary(rpout)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 920, in
> checkdest_if_necessary
>      dest_rp.conn.regress.Regress(dest_rp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/regress.py", line
> 71, in
> Regress
>      for rf in iterate_meta_rfs(mirror_rp, inc_rpath): ITR(rf.index, rf)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/rorpiter.py", line
> 281, in
> __call__
>      last_branch.fast_process(*args)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/regress.py", line
> 268, in
> fast_process
>      if rf.metadata_rorp.isreg(): self.restore_orig_regfile(rf)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/regress.py", line
> 290, in
> restore_orig_regfile
>      tf.write_from_fileobj(rf.get_restore_fp())
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/restore.py", line
> 488, in
> get_restore_fp
>      return robust.check_common_error(error_handler, get_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/robust.py", line
> 32, in
> check_common_error
>      try: return function(*args)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/restore.py", line
> 468, in
> get_fp
>      Rdiff.write_patched_fp(current_fp, delta_fp, new_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Rdiff.py", line
> 73, in
> write_patched_fp
>      rpath.copyfileobj(librsync.PatchedFile(basis_fp, delta_fp), out_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/rpath.py", line
> 64, in
> copyfileobj
>      outputfp.write(inbuf)
>
> Traceback (most recent call last):
>    File "/usr/bin/rdiff-backup-1", line 30, in <module>
>      rdiff_backup.Main.error_check_Main(sys.argv[1:])
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 304, in
> error_check_Main
>      try: Main(arglist)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 324, in Main
>      take_action(rps)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 280, in
> take_action
>      elif action == "backup": Backup(rps[0], rps[1])
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 337, in Backup
>      backup_final_init(rpout)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 501, in
> backup_final_init
>      checkdest_if_necessary(rpout)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Main.py", line
> 920, in
> checkdest_if_necessary
>      dest_rp.conn.regress.Regress(dest_rp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/regress.py", line
> 71, in
> Regress
>      for rf in iterate_meta_rfs(mirror_rp, inc_rpath): ITR(rf.index, rf)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/rorpiter.py", line
> 281, in
> __call__
>      last_branch.fast_process(*args)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/regress.py", line
> 268, in
> fast_process
>      if rf.metadata_rorp.isreg(): self.restore_orig_regfile(rf)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/regress.py", line
> 290, in
> restore_orig_regfile
>      tf.write_from_fileobj(rf.get_restore_fp())
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/restore.py", line
> 488, in
> get_restore_fp
>      return robust.check_common_error(error_handler, get_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/robust.py", line
> 32, in
> check_common_error
>      try: return function(*args)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/restore.py", line
> 468, in
> get_fp
>      Rdiff.write_patched_fp(current_fp, delta_fp, new_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/Rdiff.py", line
> 73, in
> write_patched_fp
>      rpath.copyfileobj(librsync.PatchedFile(basis_fp, delta_fp), out_fp)
>    File "/usr/lib64/python2.7/site-packages/rdiff_backup/rpath.py", line
> 64, in
> copyfileobj
>      outputfp.write(inbuf)
> IOError: [Errno 28] No space left on device
> Fatal Error: Lost connection to the remote system
> === Backup for ovirt-0 exited with error code 1 at Tue 05 May 2026
> 06:46:20 AM EDT
>
>
>
>
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