device names on a single line separated by commas, and/or you may
specify multiple Device directives. This directive is required.
-\item [Changer Device = {\it name-string}]
- \index[sd]{Changer Device}
- The specified {\bf name-string} gives the system file name of the autochanger
- device name. If specified in this resource, the Changer Device name
- is not needed in the Device resource. If it is specified in the Device
- resource (see above), it will take precedence over one specified in
- the Autochanger resource.
-
-\item [Changer Command = {\it name-string}]
+\item [Changer Device = \lt{}device-name\gt{}]
+ \index[sd]{Changer Device }
+ In addition to the Archive Device name, you may specify a {\bf Changer
+Device} name. This is because most autochangers are controlled through a
+different device than is used for reading and writing the cartridges. For
+example, on Linux, one normally uses the generic SCSI interface for
+controlling the autochanger, but the standard SCSI interface for reading and
+writing the tapes. On Linux, for the {\bf Archive Device = /dev/nst0}, you
+would typically have {\bf Changer Device = /dev/sg0}. Note, some of the more
+advanced autochangers will locate the changer device on {\bf /dev/sg1}. Such
+devices typically have several drives and a large number of tapes.
+
+On FreeBSD systems, the changer device will typically be on {\bf /dev/pass0}
+through {\bf /dev/passn}.
+
+On Solaris, the changer device will typically be some file under {\bf
+/dev/rdsk}.
+
+Please ensure that your Storage daemon has permission to access this
+device.
+
+\item [Changer Command = \lt{}command\gt{}]
\index[sd]{Changer Command }
- The {\bf name-string} specifies an external program to be called that will
- automatically change volumes as required by {\bf Bacula}. Most frequently,
- you will specify the Bacula supplied {\bf mtx-changer} script as follows.
- If it is specified here, it need not be specified in the Device
- resource. If it is also specified in the Device resource, it will take
- precedence over the one specified in the Autochanger resource.
+ This record is used to specify the external program to call and what
+arguments to pass to it. The command is assumed to be a standard program or
+shell script that can be executed by the operating system. This command is
+invoked each time that Bacula wishes to manipulate the autochanger. The
+following substitutions are made in the {\bf command} before it is sent to
+the operating system for execution:
+
+\footnotesize
+\begin{verbatim}
+ %% = %
+ %a = archive device name
+ %c = changer device name
+ %d = changer drive index base 0
+ %f = Client's name
+ %j = Job name
+ %o = command (loaded, load, or unload)
+ %s = Slot base 0
+ %S = Slot base 1
+ %v = Volume name
+\end{verbatim}
+\normalsize
+
+An actual example for using {\bf mtx} with the {\bf mtx-changer} script (part
+of the Bacula distribution) is:
+
+\footnotesize
+\begin{verbatim}
+Changer Command = "/etc/bacula/mtx-changer %c %o %S %a %d"
+\end{verbatim}
+\normalsize
+
+Where you will need to adapt the {\bf /etc/bacula} to be the actual path on
+your system where the mtx-changer script resides. Details of the three
+commands currently used by Bacula (loaded, load, unload) as well as the
+output expected by Bacula are give in the {\bf Bacula Autochanger Interface}
+section below.
\end{description}
slot number when you label Volumes.
\end{itemize}
-In version 1.37 and later, there is a new \ilink{Autochanger resource}{AutochangerRes} that permits you to group Device resources thus
-creating a multi-drive autochanger. If you have an autochanger,
-you {\bf must} use this new resource.
+The \ilink{Autochanger resource}{AutochangerRes} permits you to group
+Device resources thus creating a multi-drive autochanger. If you have an
+autochanger, you {\bf must} use this resource.
Bacula uses its own {\bf mtx-changer} script to interface with a program
that actually does the tape changing. Thus in principle, {\bf mtx-changer}
in the autochanger sequentially, you may be able to make Bacula
work with stackers (gravity feed and such).
-Support for multi-drive
-autochangers requires the \ilink{Autochanger resource}{AutochangerRes}
-introduced in version 1.37. This resource is also recommended for single
+Support for multi-drive autochangers requires the \ilink{Autochanger
+resource}{AutochangerRes}. This resource is also recommended for single
drive autochangers.
In principle, if {\bf mtx} will operate your changer correctly, then it is
The home page for the {\bf mtx} project can be found at:
\elink{http://mtx.opensource-sw.net/}{http://mtx.opensource-sw.net/}.
-Note, we have feedback from some users that there are certain
-incompatibilities between the Linux kernel and mtx. For example between
-kernel 2.6.18-8.1.8.el5 of CentOS and RedHat and version 1.3.10 and 1.3.11
-of mtx. This was fixed by upgrading to a version 2.6.22 kernel.
-
-In addition, apparently certain versions of mtx, for example, version
-1.3.11 limit the number of slots to a maximum of 64. The solution was to
-use version 1.3.10.
-
If you are having troubles, please use the {\bf auto} command in the {\bf
btape} program to test the functioning of your autochanger with Bacula. When
Bacula is running, please remember that for many distributions (e.g. FreeBSD,
minutes on a slow drive) waiting for the cassette to rewind and to unload
before the drive can be used with a different Volume.
+
+
\label{SCSI devices}
\section{Knowing What SCSI Devices You Have}
\index[general]{Have!Knowing What SCSI Devices You }
\index[general]{Devices!Multiple}
\index[general]{Multiple Devices}
-Some autochangers have more than one read/write device (drive). The
-new \ilink{Autochanger resource}{AutochangerRes} introduced in version
-1.37 permits you to group Device resources, where each device
-represents a drive. The Director may still reference the Devices (drives)
-directly, but doing so, bypasses the proper functioning of the
-drives together. Instead, the Director (in the Storage resource)
-should reference the Autochanger resource name. Doing so permits
+Some autochangers have more than one read/write device (drive). The
+\ilink{Autochanger resource}{AutochangerRes} permits you to group Device
+resources, where each device represents a drive. The Director may still
+reference the Devices (drives) directly, but doing so, bypasses the proper
+functioning of the drives together. Instead, the Director (in the Storage
+resource) should reference the Autochanger resource name. Doing so permits
the Storage daemon to ensure that only one drive uses the mtx-changer
-script at a time, and also that two drives don't reference the
-same Volume.
+script at a time, and also that two drives don't reference the same Volume.
Multi-drive requires the use of the {\bf
Drive Index} directive in the Device resource of the Storage daemon's
As a default, Bacula jobs will prefer to write to a Volume that is
already mounted. If you have a multiple drive autochanger and you want
Bacula to write to more than one Volume in the same Pool at the same
-time, you will need to set \ilink{Prefer Mounted Volumes} {PreferMountedVolumes}
+time. An alternative is to define a {\bf Maximum Concurrent Jobs} in
+the {\bf Device} resource to limit the number of simultaneous backups to
+a particular drive.
+\smallskip
+You may also to set \ilink{Prefer Mounted Volumes} {PreferMountedVolumes}
in the Directors Job resource to {\bf no}. This will cause
-the Storage daemon to maximize the use of drives.
+the Storage daemon to maximize the use of drives. However, we do not
+particularly recommend setting Prefer Mounted Volumes to no, because it
+seems to increase the number of drive conflicts that can lead to dead-lock
+situations.
\label{ConfigRecords}
\section{Device Configuration Records}
-\index[general]{Records!Device Configuration }
-\index[general]{Device Configuration Records }
-
-Configuration of autochangers within Bacula is done in the Device resource of
-the Storage daemon. Four records: {\bf Autochanger}, {\bf Changer Device},
-{\bf Changer Command}, and {\bf Maximum Changer Wait} control how Bacula uses
-the autochanger.
+\index[general]{Records!Device Configuration}
+\index[general]{Device Configuration Records}
-These four records, permitted in {\bf Device} resources, are described in
-detail below. Note, however, that the {\bf Changer Device} and the
-{\bf Changer Command} directives are not needed in the Device resource
-if they are present in the {\bf Autochanger} resource.
+Configuration of autochangers within Bacula is normally done in the
+{\bf Autochanger} resource (see below). However, first we discuss
+setting up the {\bf Device} resource for use with an autochanger.
\begin{description}
The {\bf Autochanger} record specifies that the current device is or is not
an autochanger. The default is {\bf no}.
-\item [Changer Device = \lt{}device-name\gt{}]
- \index[sd]{Changer Device }
- In addition to the Archive Device name, you must specify a {\bf Changer
-Device} name. This is because most autochangers are controlled through a
-different device than is used for reading and writing the cartridges. For
-example, on Linux, one normally uses the generic SCSI interface for
-controlling the autochanger, but the standard SCSI interface for reading and
-writing the tapes. On Linux, for the {\bf Archive Device = /dev/nst0}, you
-would typically have {\bf Changer Device = /dev/sg0}. Note, some of the more
-advanced autochangers will locate the changer device on {\bf /dev/sg1}. Such
-devices typically have several drives and a large number of tapes.
-
-On FreeBSD systems, the changer device will typically be on {\bf /dev/pass0}
-through {\bf /dev/passn}.
-
-On Solaris, the changer device will typically be some file under {\bf
-/dev/rdsk}.
-
-Please ensure that your Storage daemon has permission to access this
-device.
-
-\item [Changer Command = \lt{}command\gt{}]
- \index[sd]{Changer Command }
- This record is used to specify the external program to call and what
-arguments to pass to it. The command is assumed to be a standard program or
-shell script that can be executed by the operating system. This command is
-invoked each time that Bacula wishes to manipulate the autochanger. The
-following substitutions are made in the {\bf command} before it is sent to
-the operating system for execution:
-
-\footnotesize
-\begin{verbatim}
- %% = %
- %a = archive device name
- %c = changer device name
- %d = changer drive index base 0
- %f = Client's name
- %j = Job name
- %o = command (loaded, load, or unload)
- %s = Slot base 0
- %S = Slot base 1
- %v = Volume name
-\end{verbatim}
-\normalsize
-
-An actual example for using {\bf mtx} with the {\bf mtx-changer} script (part
-of the Bacula distribution) is:
-
-\footnotesize
-\begin{verbatim}
-Changer Command = "/etc/bacula/mtx-changer %c %o %S %a %d"
-\end{verbatim}
-\normalsize
-
-Where you will need to adapt the {\bf /etc/bacula} to be the actual path on
-your system where the mtx-changer script resides. Details of the three
-commands currently used by Bacula (loaded, load, unload) as well as the
-output expected by Bacula are give in the {\bf Bacula Autochanger Interface}
-section below.
\item [Maximum Changer Wait = \lt{}time\gt{}]
\index[sd]{Maximum Changer Wait }
\end{verbatim}
\normalsize
+\smallskip
To use the second drive, you need a second Device resource definition in the
Bacula configuration file. See the Multiple Drive section above in this
chapter for more information.
+
+\smallskip
+In addtion to the above Directives there are two others that may
+appear in a {\bf Device} resource. They are {\bf Changer Device} and
+{\bf Changer Command}. These were originally used for single drive
+autochanger prior to the implementation of the {\bf Autochanger} directive.
+With the implementation of the Autochanger directive, these two Directives
+should be specified only in the Autochanger resource. For historical
+reasons they may be specified in a {\bf Device} resource. For more
+details of these two directives see the {\bf Autochanger} documentation
+below.
+
\end{description}
In addition, for proper functioning of the Autochanger, you must
the tape device {\bf /dev/nsa1} disappear when there is no tape mounted in the
autochanger slot. As a consequence, Bacula is unable to open the device. The
solution to the problem is to make sure that some tape is loaded into the tape
-drive before starting Bacula. This problem is corrected in Bacula versions
-1.32f-5 and later.
+drive before starting Bacula.
Please see the
\borgxrlink{Tape Testing}{FreeBSDTapes}{problems}{chapter} of the \problemsman{} for {\bf important} information concerning your tape drive before doing the
\begin{verbatim}
./bconsole
Connecting to Director rufus:8101
-1000 OK: rufus-dir Version: 1.26 (4 October 2002)
+1000 OK: rufus-dir Version: 7.9.1 (29 May 2017)
*label
\end{verbatim}
\normalsize
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