Backup fails when backing up to smb share

[ibschreiber]

Hi,
backing up to a smb share using the smb option in veeam agent for linux V3.0 fails, if the share is provided by a Win 10 Pro 64Bit current patchlevel.

After some research I found that mounting the share using
//192.168.xx.xxx/Backup_Share /mnt/Backup_Share cifs cache=none,vers=2.0,users,noauto,credentials=/home/myuser/smbcredentials,uid=1000,gid=1000 0 0
and pointing the veeam client to the local mounted directory enables veeam to do successful backups again.

It looks like veeam tries to access the newly generated files and fails as the smb share is still writing it's data from the cache.

the option cache=none,vers=2.0 did the trick for me.

The win 10 machine is a plain install with veeam B&R installed on it.

Here the output:

Code: Select all

      16:02:42         Job full started at 2019-02-04 16:02:42 GMT
      16:02:43         [warn] Backup is missing in repository
      16:02:43         Preparing to backup
      16:02:43         Creating volume snapshot                                      00:00:03
      16:02:46         Starting full backup to Repository_2
      16:02:56         Backed up daten_linux_lvm 495.1 GB at 116 MB/s                01:12:51
      17:15:47         Backing up BIOS bootloader on /dev/sda                        00:00:01
      17:25:46         Backed up sda 594.7 MB at 194.7 MB/s                          00:00:03
      17:35:59         Backed up vgubuntu 123.1 GB at 137.5 MB/s                     00:15:16
      17:51:15         Backing up summary.xml                                        00:00:01
      17:51:34         [error] Failed to perform backup
      17:51:34         [error] All instances of the storage metadata are corrupted
      17:51:34         [error] Processing finished with errors at 2019-02-04 17:5...

Kind regards,
Michael

[PTide]

Hi,

Thank you for sharing that!

In fact, VAL uses mount without specifying any particular setting for "cache" parameter. That is, the value is to be determined by the client OS*. We probably can introduce some additional parameter/options to allow tuning on that part.

Thanks!

P.S. *For kernels before 3.7 the default value was "loose", starting from kernel 3.7 the default is "strict". The former allows to improve performance while sacrificing cache coherency, which might lead to corruption under certain circumstances. More details on how that happens can be found here.

[ibschreiber]

Thank you for your quick reply
Well, an additional option in veeam.ini would solve this issue
maybe something like

[smb]
option = cache=none,vers=2.0
or something like
option_cach = none
option_vers = 2.0

thanks!