[Android Software Development] morfikov:
I'm trying to make ADB Backup work, I mean the backup process works just fine I think because after typing the following command on my computer:

# adb backup --twrp data cache

I get this log inside of TWRP recovery:

I:Command 'adbbackup backup --twrp:data:cache' received
I:Set page: 'singleaction_page'
I:operation_start: 'TWRP CLI Command'
I:Inserting 'adbbackup backup --twrp:data:cache'
I:command is: 'adbbackup'
I:value is: 'backup --twrp:data:cache'
data
cache
Updating partition details...
I:Data backup size is 478MB, free: 10226MB.
I:Unable to mount '/sdcard1'
I:Actual block device: '', current file system: 'auto'
...done
I:Backup Name is: '2017-03-12--17-22-50_H10S100D00B20161207R1344'
I:Backup_Folder is: '/data/media/0/TWRP/BACKUPS/Neffos_Y5/2017-03-12--17-22-50_H10S100D00B20161207R1344'
I:Calculating backup details...
* Total number of partitions to back up: 2
* Total size of all data: 483MB
* Available space: 10226MB
[BACKUP STARTED]
* Backup Folder: /data/media/0/TWRP/BACKUPS/Neffos_Y5/2017-03-12--17-22-50_H10S100D00B20161207R1344
Backing up Data (excl. storage)...
Backups of Data do not include any files in internal storage such as pictures or downloads.
Sending TWFN to adb
I:Creating backup...
I:Writing tar file '/data/media/0/TWRP/BACKUPS/Neffos_Y5/2017-03-12--17-22-50_H10S100D00B20161207R1344/data.ext4.win' to adb backup
I:eek:pening TW_ADB_BACKUP uncompressed stream
....
...
...
...
...
I:Closing tar
opening TW_ADB_BU_CONTROL
Sending TWEOF to adb backup
I:Thread id 0 tarList done, 0 archives.
I:Thread ID 0 finished successfully.
I:createTarFork() process ended with RC=0
I:Partition Backup time: 1
Average backup rate for file systems: 4 MB/sec
[483 MB TOTAL BACKED UP]
Updating partition details...
I:Data backup size is 478MB, free: 10226MB.
I:Unable to mount '/sdcard1'
I:Actual block device: '', current file system: 'auto'
...done
I:Unmounting main partitions...
[BACKUP COMPLETED IN 121 SECONDS]
I:Copying file /tmp/recovery.log to /data/media/0/TWRP/BACKUPS/Neffos_Y5/2017-03-12--17-22-50_H10S100D00B20161207R1344/recovery.log
Backup Complete
Done processing script file

And I see the progress bar on the smartphone's screen. When it's done, I have the big file on my computer's drive.

How to restore this backup? I tried to use the following command, but I get this message in the terminal:

# adb restore ./backup.ab
Now unlock your device and confirm the restore operation.

Of course, the phone is unlocked. In the log file I have these messages:

I:Command 'adbrestore' received
I:Set page: 'singleaction_page'
I:operation_start: 'TWRP CLI Command'
I:Inserting 'adbrestore'
command is: 'adbrestore' and there is no value
I:running adb restore
I:Unable to mount '/sdcard1'
I:Actual block device: '', current file system: 'auto'
I:opening TW_ADB_BU_CONTROL
I:opening TW_ADB_TWRP_CONTROL
I:ADB Partition count: 2
I:ADB version: 1
I:ADB Type: twfilename
I:ADB Restore_Name: /data/media/0/TWRP/BACKUPS/Neffos_Y5/2017-03-12--17-22-50_H10S100D00B20161207R1344/data.ext4.win
I:ADB Restore_size: 502135249
I:ADB compression: uncompressed
E:Unable to find file system (first period).
I:Multiple archives
I:Restore filename is: /
E:Unable to find file system (first period).
E:Unknown restore method for '/data'
E:ADB Restore failed.
Done processing script file

Does anyone know what it needs? :D