ReaR backup fails due to "dd" input/ouput error

[danydany1]

Relax-and-Recover (ReaR) Issue Template

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• ReaR version: Relax-and-Recover 2.6 / 2020-06-17

• OS version: CentOS Linux release 7.8.2003 (Core)

• ReaR configuration files ("cat /etc/rear/site.conf" and/or "cat /etc/rear/local.conf"):

OUTPUT=ISO
OUTPUT_URL=cifs://10.236.9.216/sdnc/Backup_serveurs_stations/a78c-stf-tst
OUTPUT_OPTIONS="vers=3.0,cred=/root/.smbcredentials"
BACKUP=NETFS
BACKUP_URL=cifs://10.236.9.216/sdnc/Backup_serveurs_stations/a78c-stf-tst
BACKUP_OPTIONS="vers=3.0,cred=/root/.smbcredentials"
BACKUP_PROG_EXCLUDE+=( '/media' '/var/tmp' '/var/crash' '/mnt' '/tmp' )
UEFI_BOOTLOADER=/boot/efi/EFI/centos/shimx64.efi
COPY_AS_IS+=( /root/.smbcredentials )
BACKUP_PROG_COMPRESS_OPTIONS=("--gzip")
BACKUP_PROG_COMPRESS_SUFFIX=".gz"

• Hardware or virtual machine: VM Microsoft Hyper-V 10.0.14393.0

• System architecture : x86_64

• Firmware : UEFI

• Description of the issue (ideally so that others can reproduce it):
  Sometimes I have the following error using "rear -v -d mkbackup":

....
2021-01-05 09:26:01.558388400 Including backup/default/010_pre_backup_script.sh
2021-01-05 09:26:01.563060400 Including backup/NETFS/default/100_mount_NETFS_path.sh
mkdir: created directory '/tmp/rear.b04D88M3KpAnOXY/outputfs'
2021-01-05 09:26:01.566031300 Added 'rmdir -v /tmp/rear.b04D88M3KpAnOXY/outputfs >&2' as an exit task
2021-01-05 09:26:01.571774900 Mounting with 'mount -v -o vers=3.0,cred=/root/.smbcredentials //10.236.9.216/sdnc/Backup_serveurs_stations/a78c-stf-tst /tmp/rear.b04D88M3KpAnOXY/outputfs'
domain=sdnc.dgfip
mount.cifs kernel mount options: ip=10.236.9.216,unc=\\10.236.9.216\sdnc,vers=3.0,user=stf_tst,domain=sdnc.dgfip,prefixpath=Backup_serveurs_stations/a78c-stf-tst,pass=********
2021-01-05 09:26:01.642590600 Added 'umount -f -v '/tmp/rear.b04D88M3KpAnOXY/outputfs' >&2' as an exit task
2021-01-05 09:26:01.654183400 Including backup/NETFS/default/150_save_copy_of_prefix_dir.sh
2021-01-05 09:26:01.659979000 Including backup/NETFS/default/200_check_rsync_relative_option.sh
2021-01-05 09:26:01.664195000 Added option '--relative' to the BACKUP_RSYNC_OPTIONS array during mkbackup workflow
2021-01-05 09:26:01.669191300 Including backup/NETFS/default/200_make_prefix_dir.sh
2021-01-05 09:26:01.686730800 Including backup/NETFS/default/250_create_lock.sh
2021-01-05 09:26:01.720388100 Including backup/NETFS/GNU/Linux/310_stop_selinux.sh
2021-01-05 09:26:01.724401800 Temporarily stopping SELinux enforce mode with BACKUP=NETFS and BACKUP_PROG=tar backup
2021-01-05 09:26:01.730297400 Including backup/NETFS/default/400_create_include_exclude_files.sh
2021-01-05 09:26:01.736037000 Including backup/NETFS/default/500_make_backup.sh
2021-01-05 09:26:01.743548600 Making backup (using backup method NETFS)
2021-01-05 09:26:01.745494700 Backup include list (backup-include.txt contents):
2021-01-05 09:26:01.747274900   /app
2021-01-05 09:26:01.749046700   /produits
2021-01-05 09:26:01.750796400   /
2021-01-05 09:26:01.752550500   /tmp
2021-01-05 09:26:01.754319600   /var
2021-01-05 09:26:01.756070500   /var/log
2021-01-05 09:26:01.757790400   /boot/efi
2021-01-05 09:26:01.759537200   /boot
2021-01-05 09:26:01.761257100 Backup exclude list (backup-exclude.txt contents):
2021-01-05 09:26:01.763041700   /tmp/*
2021-01-05 09:26:01.764783700   /dev/shm/*
2021-01-05 09:26:01.766551900   /var/lib/rear/output/*
2021-01-05 09:26:01.768262200   /media
2021-01-05 09:26:01.769994500   /var/tmp
2021-01-05 09:26:01.771729500   /var/crash
2021-01-05 09:26:01.773448200   /mnt
2021-01-05 09:26:01.775165100   /tmp
2021-01-05 09:26:01.776880300   /tmp/rear.b04D88M3KpAnOXY
2021-01-05 09:26:01.778869600 Creating tar archive '/tmp/rear.b04D88M3KpAnOXY/outputfs/a78c-stf-tst/backup.tar.gz'
2021-01-05 09:26:01.791372500 tar --warning=no-xdev --sparse --block-number --totals --verbose --no-wildcards-match-slash --one-file-system --ignore-failed-read --anchored --xattrs --xattrs-include=security.capability --xattrs-include=security.selinux --acls --gzip -X /tmp/rear.b04D88M3KpAnOXY/tmp/backup-exclude.txt -C / -c -f - /app /produits / /tmp /var /var/log /boot/efi /boot /var/log/rear/rear-a78c-stf-tst.log | dd of=/tmp/rear.b04D88M3KpAnOXY/outputfs/a78c-stf-tst/backup.tar.gz bs=1M
stat: missing operand
Try 'stat --help' for more information.
2021-01-05 09:39:44.297981000 ERROR: openssl failed with return code 1 and below output:
  ---snip---

  ----------
This means that the archiving process ended prematurely, or did
not even start. As a result it is unlikely you can recover this
system properly. Relax-and-Recover is therefore aborting execution.

===== Stack trace =====
Trace 0: /usr/sbin/rear:541 main
Trace 1: /usr/share/rear/lib/mkbackup-workflow.sh:26 WORKFLOW_mkbackup
Trace 2: /usr/share/rear/lib/framework-functions.sh:116 SourceStage
Trace 3: /usr/share/rear/lib/framework-functions.sh:56 Source
Trace 4: /usr/share/rear/backup/NETFS/default/500_make_backup.sh:313 source
=== End stack trace ===
2021-01-05 09:39:44.311832700 Exiting rear mkbackup (PID 33349) and its descendant processes ...
2021-01-05 09:39:47.360702500 rear,33349 /usr/sbin/rear -v -d mkbackup
  `-rear,61301 /usr/sbin/rear -v -d mkbackup
      `-pstree,61302 -Aplau 33349
/usr/share/rear/lib/_input-output-functions.sh: line 151: kill: (61305) - No such process
2021-01-05 09:39:47.443393100 Running exit tasks
2021-01-05 09:39:47.445388700 Exit task 'umount -f -v '/tmp/rear.b04D88M3KpAnOXY/outputfs' >&2'
umount: /tmp/rear.b04D88M3KpAnOXY/outputfs (//10.236.9.216/sdnc/Backup_serveurs_stations/a78c-stf-tst) unmounted
2021-01-05 09:39:48.036068200 Exit task 'rmdir -v /tmp/rear.b04D88M3KpAnOXY/outputfs >&2'
rmdir: removing directory, '/tmp/rear.b04D88M3KpAnOXY/outputfs'
2021-01-05 09:39:48.049797900 Exit task 'cleanup_build_area_and_end_program'
2021-01-05 09:39:48.051671000 Finished in 927 seconds
2021-01-05 09:39:48.053688400 You should also rm -Rf /tmp/rear.b04D88M3KpAnOXY
2021-01-05 09:39:48.056066700 End of program reached
2021-01-05 09:39:48.058616400 Exit task '(( EXIT_FAIL_MESSAGE )) && echo 'rear mkbackup failed, check /var/log/rear/rear-a78c-stf-tst.log for details' 1>&8'
2021-01-05 09:39:48.060294100 Exit task 'exec 8>&-'
2021-01-05 09:39:48.061967200 Exit task 'exec 7>&-'
2021-01-05 09:39:48.063741800 Exit task 'exec 6<&-'
2021-01-05 09:39:48.065459200 Exit task ''

At the end of the file /tmp/rear.RSoiKQtYLwt4v25/tmp/backup.log, I get:

...
block 35287237: /boot/config-3.10.0-1127.8.2.el7.x86_64
block 35287540: /boot/symvers-3.10.0-1127.8.2.el7.x86_64.gz
block 35288169: /boot/vmlinuz-3.10.0-1127.8.2.el7.x86_64
block 35301381: /boot/initramfs-3.10.0-1127.8.2.el7.x86_64.img
block 35344020: /boot/initramfs-0-rescue-dfa2d891ef0f4dde962104bac34b6d27.img
block 35474153: /boot/vmlinuz-0-rescue-dfa2d891ef0f4dde962104bac34b6d27
block 35487365: /boot/initramfs-3.10.0-327.28.3.el7.x86_64.img
block 35527751: /var/log/rear/rear-a78c-stf-tst.log
Total bytes written: 18190213120 (17GiB, 22MiB/s)
dd: closing output file '/tmp/rear.b04D88M3KpAnOXY/outputfs/a78c-stf-tst/backup.tar.gz': Input/output error

Maybe there's some issue related to the CIFS share where the backup is stored.

• Workaround, if any:
  None for the moment.

[gdha]

@danydany1 a dd I/O error can have several reasons why it happens:

• network glitch with CIFS
• out-of-space issue
  We do not expect this is a ReaR issue as such, but rather environmental one.

[danydany1]

Yes you're right.

I use Rear backup in crontab.
I tried to change the moment when rear backup is launched and it works better.
I have probably a CIFS or a network issue so I try to Rear backup when network is less "busy".
I have to inspect further and check exactly why "dd" sometimes fails.

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