\item [compression=GZIP]
\index[dir]{compression}
\index[dir]{Directive!compression}
- All files saved will be software compressed using the GNU ZIP compression
- format. The compression is done on a file by file basis by the File daemon.
- If there is a problem reading the tape in a single record of a file, it will
- at most affect that file and none of the other files on the tape. Normally
- this option is {\bf not} needed if you have a modern tape drive as the drive
- will do its own compression. In fact, if you specify software compression at
- the same time you have hardware compression turned on, your files may
- actually take more space on the volume.
-
- Software compression is very important if you are writing your Volumes to a
- file, and it can also be helpful if you have a fast computer but a slow
- network, otherwise it is generally better to rely your tape drive's hardware
- compression. As noted above, it is not generally a good idea to do both software
- and hardware compression.
-
- Specifying {\bf GZIP} uses the default compression level six (i.e. {\bf GZIP}
- is identical to {\bf GZIP6}). If you want a different compression level (1
- through 9), you can specify it by appending the level number with no
- intervening spaces to {\bf GZIP}. Thus {\bf compression=GZIP1} would give
- minimum compression but the fastest algorithm, and {\bf compression=GZIP9}
- would give the highest level of compression, but requires more computation.
- According to the GZIP documentation, compression levels greater than 6
- generally give very little extra compression and are rather CPU intensive.
+ All files saved will be software compressed using the GNU ZIP
+ compression format. The compression is done on a file by file basis by
+ the File daemon. If there is a problem reading the tape in a single
+ record of a file, it will at most affect that file and none of the other
+ files on the tape. Normally this option is {\bf not} needed if you have
+ a modern tape drive as the drive will do its own compression. In fact,
+ if you specify software compression at the same time you have hardware
+ compression turned on, your files may actually take more space on the
+ volume.
+
+ Software compression is very important if you are writing your Volumes
+ to a file, and it can also be helpful if you have a fast computer but a
+ slow network, otherwise it is generally better to rely your tape drive's
+ hardware compression. As noted above, it is not generally a good idea
+ to do both software and hardware compression.
+
+ Specifying {\bf GZIP} uses the default compression level six (i.e. {\bf
+ GZIP} is identical to {\bf GZIP6}). If you want a different compression
+ level (1 through 9), you can specify it by appending the level number
+ with no intervening spaces to {\bf GZIP}. Thus {\bf compression=GZIP1}
+ would give minimum compression but the fastest algorithm, and {\bf
+ compression=GZIP9} would give the highest level of compression, but
+ requires more computation. According to the GZIP documentation,
+ compression levels greater than 6 generally give very little extra
+ compression and are rather CPU intensive.
\item [signature=SHA1]
\index[dir]{signature}
+\index[dir]{SHA1}
\index[dir]{Directive!signature}
- An SHA1 signature will be computed for all The SHA1 algorithm is purported to
- be some what slower than the MD5 algorithm, but at the same time is
- significantly better from a cryptographic point of view (i.e. much fewer
- collisions, much lower probability of being hacked.) It adds four more bytes
- than the MD5 signature. We strongly recommend that either this option or MD5
- be specified as a default for all files. Note, only one of the two options
- MD5 or SHA1 can be computed for any file.
+ An SHA1 signature will be computed for all The SHA1 algorithm is
+ purported to be some what slower than the MD5 algorithm, but at the same
+ time is significantly better from a cryptographic point of view (i.e.
+ much fewer collisions, much lower probability of being hacked.) It adds
+ four more bytes than the MD5 signature. We strongly recommend that
+ either this option or MD5 be specified as a default for all files.
+ Note, only one of the two options MD5 or SHA1 can be computed for any
+ file.
\item [signature=MD5]
- \index[dir]{signature}
- \index[dir]{Directive!signature}
- An MD5 signature will be computed for all files saved. Adding this option
- generates about 5\% extra overhead for each file saved. In addition to the
- additional CPU time, the MD5 signature adds 16 more bytes per file to your
- catalog. We strongly recommend that this option or the SHA1 option be
- specified as a default for all files.
+\index[dir]{signature}
+\index[dir]{MD5}
+\index[dir]{Directive!signature}
+ An MD5 signature will be computed for all files saved. Adding this
+ option generates about 5\% extra overhead for each file saved. In
+ addition to the additional CPU time, the MD5 signature adds 16 more
+ bytes per file to your catalog. We strongly recommend that this option
+ or the SHA1 option be specified as a default for all files.
\item [verify=\lt{}options\gt{}]
\index[dir]{verify}
\item [onefs=yes|no]
\index[dir]{onefs}
\index[dir]{Directive!onefs}
- If set to {\bf yes} (the default), {\bf Bacula} will remain on a single file
- system. That is it will not backup file systems that are mounted on a
- subdirectory. If you are using a *nix system, you may not even be aware
- that there are several different filesystems as they are often
- automatically mounted by the OS (e.g. /dev, /net, /sys, /proc, ...).
- With Bacula 1.38.0 or later, it will inform you when it decides not
- to traverse into another filesystem. This can be very useful if you
- forgot to backup a particular partition. An example of the
- informational message in the job report is:
+ If set to {\bf yes} (the default), {\bf Bacula} will remain on a single
+ file system. That is it will not backup file systems that are mounted
+ on a subdirectory. If you are using a *nix system, you may not even be
+ aware that there are several different filesystems as they are often
+ automatically mounted by the OS (e.g. /dev, /net, /sys, /proc, ...).
+ With Bacula 1.38.0 or later, it will inform you when it decides not to
+ traverse into another filesystem. This can be very useful if you forgot
+ to backup a particular partition. An example of the informational
+ message in the job report is:
+
+\footnotesize
+\begin{verbatim}
+rufus-fd: /misc is a different filesystem. Will not descend from / into /misc
+rufus-fd: /net is a different filesystem. Will not descend from / into /net
+rufus-fd: /var/lib/nfs/rpc_pipefs is a different filesystem. Will not descend from /var/lib/nfs into /var/lib/nfs/rpc_pipefs
+rufus-fd: /selinux is a different filesystem. Will not descend from / into /selinux
+rufus-fd: /sys is a different filesystem. Will not descend from / into /sys
+rufus-fd: /dev is a different filesystem. Will not descend from / into /dev
+rufus-fd: /home is a different filesystem. Will not descend from / into /home
+\end{verbatim}
+\normalsize
+
+ Note: in previous versions of Bacula, the above message was of the form:
\footnotesize
\begin{verbatim}
-rufus-fd: Filesystem change prohibited. Will not descend into /misc
-rufus-fd: Filesystem change prohibited. Will not descend into /net
-rufus-fd: Filesystem change prohibited. Will not descend into /var/lib/nfs/rpc_pipefs
-rufus-fd: Filesystem change prohibited. Will not descend into /selinux
-rufus-fd: Filesystem change prohibited. Will not descend into /sys
-rufus-fd: Filesystem change prohibited. Will not descend into /dev
-rufus-fd: Filesystem change prohibited. Will not descend into /home
+Filesystem change prohibited. Will not descend into /misc
\end{verbatim}
\normalsize
+
If you wish to backup multiple filesystems, you can explicitly
list each filesystem you want saved. Otherwise, if you set the onefs option
to {\bf no}, Bacula will backup all mounted file systems (i.e. traverse mount
explicitly name each filesystem you want backed up. Explicitly naming the
filesystems you want backed up avoids the possibility of getting into a
infinite loop recursing filesystems. Another possibility is to
- use {\bf onefs=no} and to set {\bs fstype=ext2, ...}.
+ use {\bf onefs=no} and to set {\bf fstype=ext2, ...}.
See the example below for more details.
If you think that Bacula should be backing up a particular directory
Also be aware that even if you include {\bf /home} in your list
of files to backup, as you most likely should, you will get the
- informational message about Filesystem change prohibited when Bacula is
- processing the {\bf /} directory.
+ informational message that "/home is a different filesystem" when
+ Bacula is processing the {\bf /} directory. This message does not
+ indicate an error. This message means that while examining the
+ {\bf File =} referred to in the second part of the message, Bacula will
+ not descend into the directory mentioned in the first part of the message.
+ However, it is possible that the separate filesystem will be backed up
+ despite the message. For example, consider the following FileSet:
+
+\footnotesize
+\begin{verbatim}
+ File = /
+ File = /var
+\end{verbatim}
+\normalsize
+
+ where {\bf /var} is a separate filesystem. In this example, you will get a
+ message saying that Bacula will not decend from {\bf /} into {\bf /var}. But
+ it is important to realise that Bacula will descend into {\bf /var} from the
+ second File directive shown above. In effect, the warning is bogus,
+ but it is supplied to alert you to possible omissions from your FileSet. In
+ this example, {\bf /var} will be backed up. If you changed the FileSet such
+ that it did not specify {\bf /var}, then {\bf /var} will not be backed up.
+
+
\label{portable}
exec > /dev/null
\end{verbatim}
+\item [noatime=yes|no]
+\index[dir]{noatime}
+\index[dir]{Directive!noatime}
+ If enabled, and if your Operating System supports the O_NOATIME file
+ open flag, Bacula will open all files to be backed up with this option.
+ It makes it possible to read a file without updating the inode atime
+ (and also without the inode ctime update which happens if you try to set
+ the atime back to its previous value). It also prevents a race
+ condition when two programs are reading the same file, but only one does
+ not want to change the atime. It's most useful for backup programs and
+ file integrity checkers (and bacula can fit on both categories).
+
+ This option is particularly useful for sites where users are sensitive
+ to their MailBox file access time. It replaces both the {\bf keepatime}
+ option without the inconvienences of that option (see below).
+
+ If your Operating System does not support this option, it will be
+ silently ignored by Bacula.
+
\item [mtimeonly=yes|no]
\index[dir]{mtimeonly}
\item [hardlinks=yes|no]
\index[dir]{hardlinks}
\index[dir]{Directive!hardlinks}
- When enabled (default), this directive will cause hard inks to be
+ When enabled (default), this directive will cause hard links to be
backed up. However, the File daemon keeps track of hard linked files and
will backup the data only once. The process of keeping track of the
hard links can be quite expensive if you have lots of them (tens of
\normalsize
to give you a listing of all files that match.
-
projects / bacula / docs / blobdiff