Snapshot tool elastio-snap vs. dattobd: Support of newer kernels

client
1

Dear all,

I cannot dattobd currently due to known kernel issues as I want to run > 5.4, see github:

As far as I found out, there is a fork of dattobd, that solved several issues, however, source code was not included into dattobd:

Is there a chance to somehow utilize elastio-snap instead of dattobd with urbackup clients?

Best
aradhir

2

You just need to adapt the scripts referenced at /usr/local/etc/urbackup/snapshot.cfg to the different command line tool (probably).

3

Hi,

I’m trying to make the conversion to elastio-snap from datto, but it is not working. I get an error when trying to mount wsnap to the backups folder. Here is the command and the messages that I get (I added some debug messages:

sudo /usr/local/share/urbackup/elastio_create_snapshot 123 "/" "/dev/vda3" "/dev/vda3" 2>&1
SNAP_ID=123
SNAP_MOUNTPOINT=/
SNAP_DEST=/mnt/urbackup_snaps/123
SNAP_MOUNTPOINT_SAN=_
SNAP_NUM_PATH=/mnt/urbackup_snaps/cbt_info/_-snapdev
SNAP_COWFILE_PATH=/mnt/urbackup_snaps/cbt_info/_-cowfile
Snapshotting device /dev/vda3 via elastio...
Using /dev/elastio-snap0...
CBT=type=datto&reset=1
/dev/elastio-snap0 DEV_SIZE=191881216
The truncate command is: truncate -s100M /.overlay_2fefd007-3e48-4162-b2c6-45ccdda22f37_123
LODEV=/dev/loop25
dmsetup options: 0 191881216 snapshot /dev/elastio-snap0 /dev/loop25 N 8
Name:              wsnap-123
State:             ACTIVE
Read Ahead:        256
Tables present:    LIVE
Open count:        0
Event number:      0
Major, minor:      253, 0
Number of targets: 1

Mounting /dev/mapper/wsnap-123
The mount command is: mount -o ro /dev/mapper/wsnap-123 /mnt/urbackup_snaps/123
mount: /mnt/urbackup_snaps/123: wrong fs type, bad option, bad superblock on /dev/mapper/wsnap-123, missing codepage or helper program, or other error.
Mounting filesystem failed

The disk is the following:
Disk /dev/vda: 92 GiB, 98784247808 bytes, 192937984 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: A712339D-9AFF-4102-8432-C359FF195D77

Device Start End Sectors Size Type
/dev/vda1 2048 4095 2048 1M BIOS boot
/dev/vda2 4096 1054719 1050624 513M EFI System
/dev/vda3 1054720 192935935 191881216 91,5G Linux filesystem

vda3 is an ext4 partition.

Kernel is:
5.19.0-46-generic #47~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jun 21 15:35:31 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

I installed elastio according to their instructions for Ubuntu 22.04. Their test works (creating a snapshot and backing up the device with dd).

The script that creates the snapshot is the following:
elastio_create_snapshot.txt (4.3 KB)

Any idea?

Thanks,
Bogdan