Question: How to read and understand a backup log and errors/solutions in it

Q1. How does a backup log look like?

Q2. How can I read a backup log?

Q3. Backup failed. What should I do?


Solution:

Q1. How does a backup log look like?

The following is the example of a backup log.

Example:

A backup log generated by a LinkStation looks like the following, and it will be saved as a text file on a backup source.

-------- BEGIN BACKUP 2006/09/07 18:05:44 array1/share -> TS-TGL6F0@usbdisk1 --------
building file list ...
174 files to consider
created directory /mnt/usbdisk1/_backups
./

(...Backup Lists...)

sent 24057 bytes received 3340 bytes 18264.67 bytes/sec
total size is 14847 speedup is 0.54
-------- END BACKUP 2006/09/07 18:05:45 array1/shrare -> TS-TGL6F0@usbdisk1 --------

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Q2. How can I read a backup log?

The following table explains how to read a backup job.

-------- BEGIN BACKUP (The time when the backup was started) (The shared folder name in the backup source) ->
(The shared folder in the Backup destination) --------
  building file list ...
(The number of files to be backed up) files to consider
* created directory (a folder name which was newly created at the backup job)
・・・

*File lists of backup source
・・・

sent (1.The number of Bytes sent) bytes received (2. The number of Bytes received) bytes (3. Average transfer rate) bytes/sec
total size is (4. Total amount of transferred data) speedup is (5. Data transfer effectiveness)

* Error Log

-------- END BACKUP (The time when backup was done) (The hared folder name in the backup source) ->
(The shared folder name in the backup destination)--------

1.The number of bytes sent The amount of information sent from a backup destination to a backup source.
This includes “Total size transferred (4)” as well as information to control a backup function.
2. The number of bytes received The amount of data that the source received from the destination.
This contains the information that controls the backup function.
3. Average transfer rate An average transfer rate at which the backup from the source to the destination was performed by the backup function (rsync)
4. Total amount of transferred data Total amount of data which was backed up by the backup function (rsync) function from backup source.
5. Data transfer effectiveness This is the data transfer effectiveness when using the backup function (rsync).
This rate can be used to determine how effectively the backup function (rsync) can back up data comparing to a regular file copy.
* Formula: [4. Total amount of transferred data] / [1.The number of bytes sent + 2. the number of bytes received]

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Q3. Backup failed. What should I do?

The following lists explain how to read an error log and its solution when an error happens during the backup job.

If you see the words "error", or "code **", an error has occurred during the backup job (The ** indicates the number).

The following lists include errors, possible causes and solutions that can be seen in the log,

Error The "code 12" is in the log.
Causes - Connection (session) with a backup destination has been disconnected.
- A hub in the transfer route is turned off.
- Communications in the backup route (such as a wireless connection) become unstable.
Solutions - During a backup job, do not change the configurations of the backup source by using the web browser, reboot the unit, or perform the disk check for the source device.
- Check your network configuration and change it if necessary (such as switching wireless connection to wired connection.
Example of a log rsync: read error: Connection reset by peer (104)
rsync error: error in rsync protocol data stream (code 12) at io.c(515)
rsync error: error in rsync protocol data stream (code 12) at io.c(359)

Error The "code 20" is in the log.
Causes - A backup process was terminated abnormally.
Solutions - Do not change or navigate the web browser setting screen for backup source and destination during the backup job.
Example of a log rsync error: received SIGUSR1 or SIGINT (code 20) at rsync.c(231)
rsync error: received SIGINT, SIGTERM, or SIGHUP (code 20) at rsync.c(242) [sender]

Error The "code 23" is in the log.
Causes - The prohibited characters of LinkStation and TeraStation are used in a file or folder name of the backup source.
- You are trying to copy the specific folder/file that you are not allowed to copy.
Solutions - Change all folder names or file names which include the prohibited characters.
- Delete the specific folder/file which cannot be copied.

* If you cannot backup to a USB hard disk formatted in FAT32
 This may be solved by formatting in XFS.
Example of a log rsync error: some files could not be transferred (code 23) at main.c(892) [sender=2.6.8]
rsync error: some files could not be transferred (code 23) at main.c(702)

Error The "code 24" is in the log.
Causes - A backup process was terminated abnormally.
- When the backup was started, the backup source file was edited with software which creates a tmp (temporarily) file, such as Word and Excel.
Solutions - Do not edit a backup source file during a backup job.
Example of a log rsync error: some files vanished before they could be transferred (code 24) at main.c(702)
rsync warning: some files vanished before they could be transferred (code 24) at main.c(702)

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