Configuration of AF's backup system
===================================
The parameters for the client side can be found in a
file named
afclient.conf
and for the server side in
afserver.conf,
that resides in the
directory /etc/afbackup
or /etc/afbackup,
respectively. Comments in those files are lines starting
with the pound symbol # as the first non-blank character.
These two files need not be edited by hand with an editor,
instead the programs /usr/sbin/afserverconfig [ configfile ]
and /usr/sbin/afclientconfig [ configfile ]
can be used. If you are
running X, the programs are the same, but start with an 'x';
(Tcl/Tk must be installed):
/usr/sbin/xafserverconfig [ configfile ]
and /usr/sbin/xafclientconfig [ configfile ] .
The parameters described below are the same for both versions.
Server configuration parameters
-------------------------------
ServerIdentifier
The identifier for the server. Default: The official hostname,
followed by a colon and the full path to the configuration file.
The server identifier can be used to become independent of the
server machine name. This might be helpful, if the backup server
should move to another machine. Whitespace characters may be
used in this identifier, but they are replaced with asterisks *
before comparing, so they are not significant
Backup-Device
This is the device the backup is written to. It can be any
tape device with the capability to distinguish between several
files on the media. It is mandatory to supply the no-rewind
device here, otherwise this package won't work properly.
Suitable device names for some OS-es:
AIX: /dev/rmt0.1
Solaris: /dev/rmt/0bn
IRIX: /dev/rmt/tps0d4nr
HP-UX: /dev/rmt/0hn
Linux: /dev/nst0
Digital UNIX: /dev/nrmt0h
FreeBSD: /dev/nsa0
If the drive has a media handler attached, a specifier for this
may follow the device name. The format for this is
=<drive-count>@<device>#<num-slots>^<num-loadbays> , for example
=1@/dev/sg0#6^2 . Whitespace before and following the special
characters = @ and # is allowed for readability. The example
means: The drive is number 1 in the changer, /dev/sg0 is the
changer device, that has 6 media slots and 2 loadbays. The
parts =<drive-count> and ^<num-loadbays> are optional.
If the server is only used for remote start and no real backup
device should be accessed, a dash - should be configured here
as device, so a respective warning to the server log will be
suppressed
Tape-Blocksize
The blocksize of the tape device. This value specifies how many
bytes are written to tape or read from it with one system call.
Usually this value is at least 512 or a multiple of it.
It is not very important if the blocksize is set to 2048
or 1024. The main thing to keep in mind is that if there is a
minimum, it should be respected (e.g. 1024 on AIX), otherwise
media space is wasted.
Tape-Buffer
Three numbers and a filename can be given here. The first number
is the desired size of the tape buffer in bytes. The optional
second number is the high-watermark while writing in percent
(default: 67), the optional third number is the low watermark,
also in percent (default: 0). As long as the buffer fill rate
does not reach the high watermark, nothing is written, but when
it is reached, writing does not stop until the buffer fill rate
is equal or below the low watermark. This procedure hopefully
reduces tape wear and increases average writing speed, because
excessive tape stops/starts are avoided. If the optional filename
is given, buffering is done in the given file, which is mapped
into the server's address space for that purpose. In the filename,
patterns are replaced like with Changer-Configuration-File.
Cartridge-Handler
This value must be 1 or 0, which means, that you either have a
cartridge handling system (i.e. some kind of robot) (1) or
not (0). If you don't have a robot, you may nonetheless maintain
a set of cartridges, that you will have to manually number.
The backup server side will inform you via email or console output,
whenever another cartridge has to be inserted into the drive and what
number it requires it is.
Number Of Cartridges
This number specifies, how many cartridges you are maintaining.
If you have a cartridge handling system (some kind of robot),
this is usually the number of cartridges, your system is juggling.
Cartridge-Sets
Several cartridge sets can be used. Here they can be specified.
The specifiers for the cartridge sets must be separated by
whitespace. Each specifier may consist of digits, commas and
dashes. Examples for cartridge set specifiers: 1-5 7-9,12 6,10,11
This example shows how to specify three cartridge sets. If the
access to a cartridge set should be allowed only for certain
clients, this may specified with a colon immediately following
the set specifier without whitespace, followed by one of three
forms: Either a list of hostnames, separated by commas and no
whitespace inbetween, or the full path to a file containing the
hostnames one per line, or by a command to be executed. The
command must start with a bar | and must be enclosed in double
quotes, if it is containing whitespace. If %H occurres in the
command it will be replaced with the client name, who wants to
gain access to the cartridge set. The command must exit with a
status of 0, if access is to be granted, otherwise with an exit
status unequal to 0. The name of the host to be checked is also
written to standard input of this command, so %H needs not to
be used. Examples specifying cartridge sets with restricted
access: 1-5:apollo,localhost,taurus
6-8,16:/usr/local/backup/etc/set2clients
9-15:"| fgrep .my.domain.com"
Remember, that grep will exit with 0, if a match has been found,
otherwise 1. Note, that localhost and the network name of the
machine should be both given, if the server is also a client.
The names to be supplied here are not the client IDs configured
on the client side, but the network names of the machines.
If this parameter is not given, there is only the default set
number 1 with all available cartridges, access is permitted to
any client. Not all cartridges need to be included in a set and
sets must not overlap.
PrintServerMessages
By default the server sends messages about current problems
or required actions to a maintainer or, if determinable and
configured, to the user on the client side. They cannot be seen
as output on the client side. When this parameter is set, these
messages are also output on the client side. The first word
must consist of the letters b, v, r and c, that means: messages
are output during backup, verify, restore, and/or copy-tape
depending on what letters appear. The next fields must name the
respective single stream server ports or service names according
to the configured ports in BackupPorts, i.e. wherever a multi
stream port appears in the configuration in BackupPorts, here
the respective single stream service must be named. If not given
the values default to the ones configured in BackupPorts. If
this parameter is not properly configured, the messages might
not be seen on the client side for technical reasons.
Max Bytes Per File
The stream of data, that represents your backup, is divided into
pieces (files on tape). This is done to find the files faster
during a restore. This value determines, how large the pieces on
tape may be in bytes. Some good values for a few tape technologies:
QIC: 20000000
DAT: 30000000
Exabyte: 50000000
DLT: 100000000
Max Bytes Per Tape
With this entry the number of bytes written to a single tape
can be limited. Serveral entries with a leading range specifier
allow to handle certain tapes differently. The range specifier
must end in a colon : and may contain lists of ranges and numbers.
A given number without a leading range specifier will be valid for
all tapes not explicitly described. Default is use of full tape
capacity. Several entries must be separated by whitespace and may
look like the following examples:
4000000000 1,3-5:3500000000 7,9-:5000000000
This means: 3.5 GB for cartridges 1 and 3 through 5, 5 GB
for cartridges 7 and 9 up to the last cartridge, 4 GB for the
rest
Full Append Mode
Normally, when the insert (writing) position is forced to
another tape with the cartis command or with the clientside
option -G, the rest of the current tape remains unused. When
this option is set to 1, it will nonetheless be used to write
data on, if there is no free tape left
Variable Append Mode
In default mode, the place (tape and tapefile), where the next data
will be written, is fix and can only manipulated using the command
cartis or the clientside option -G. When the server wants to write
with variable append mode enabled, any cartridge, that is in the
drive, is belonging to the right cartridge set and is allowed to be
written, will be accepted and appended to. Note, that this will also
override the settings of cartis or option -G.
Reject Unlabeled Tapes
Default is to accept an unlabeled tape as the requested one and
to label it automatically. If this behaviour is unwanted and only
tapes with a recognized label should be permitted for writing,
this parameter should be set.
PreferCartInChanger
When a tape gets full and another one must be chosen to continue
writing, the server does not make a difference, whether a tape
is available in a changer or not, if this flag is not set. This
is the default. If this parameter is set, the next cartridge is
chosen from those, that are available in the slots of a changer,
if present and configured. If there is no tape found inside the
changer, that is allowed to be overwritten, manual administrator
interaction is nonetheless required.
Cart-Insert-Gracetime
This is the time in seconds, the program waits after another
cartridge has been put into the drive. Normal devices need a
certain time span to mount the tape to get it ready for use.
Normally this value is not critical. If you estimate it too
low, the ioctl-system-call will wait until the device becomes
available. This time is sometimes longer than two minutes,
so if you want to proceed quickly after a cartridge
change, you may measure the maximum time your system needs.
Some tried values for a few tape technologies:
QIC: 20
DAT: 30
Exabyte: 70
DLT: 70
Device-Unavailable-Send-Mail-After-Min
If the streaming device is not accessible (i.e. an open or a
tape handling command fails) or another backup server process
is still running, the server process re-tries his attempts
regularly. If it fails longer than the time in minutes
supplied here, an e-mail is sent to the configured user in
charge (see: User To Inform). Supplying 0 means: never send mail.
Device-Unavailable-Give-Up-After-Min
Same as Device-Unavailable-Send-Mail-After-Min, but this time
not an e-mail is sent, but the server process exits silently
leaving a warning in the log file. Supplying 0 means: try
forever, never exit.
Device-Probe Interval
This is the interval in seconds, after that regularly the device
is probed to be ready for reading. Thus after having ejected a
cartridge it is automatically recognized, if a new cartridge has
been inserted. For other media (e.g. exchangeable disks) this may
not be suitable. Supply a 0 in these cases for no probing.
SetFile-Command
This is the (shell-) command to run to position the tape to a
certain file. Usually this is something like a combination
of: mt -f <device> rewind and mt -f <device> fsf <number>.
If the command you are supplying here starts to count with
1 for the first file on tape, you should insert %n for the
<number>. If it starts with 0, replace <number> with %m. If
you don't want to type the devicename again here, you may
write %d instead. For more pattern replacements see: Status-file
SkipFile-Command
This is the (shell-) command to run to skip over to a file
later on tape. Usually this is something like
mt -f <device> fsf <number>
Insert %n, where the number of files to skip over must be
supplied in the command, in the example instead of <number>,
and %d, where the device should appear (here: <device>).
For more pattern replacements see: Status-file
Setcart-Command
This is the (shell-) command to run to put a certain
cartridge into the device. If the command you are supplying
here starts to count with 1 for the first cartridge, you
should insert %n in the place, where the cartridge number
must appear. If it starts with 0, replace it with %m. If
you don't want to type the devicename again here, you may
write %d instead. If you don't have a command to perform
this task, don't supply anything here. In this case you must
set your cartridge handling system to sequential mode
(automatically putting the next cartridge in, when the
current one is ejected).
For pattern replacements see: Status-file
Changecart-Command
This is the (shell-) command to run to eject a cartridge
currently placed inside the streamer device. This is normally
something like mt -f <device> rewoffl (but better consult
your man-pages). You have to supply this either if you have
no cartridge handling system (robot) or if you have no
command to set the cartridge directly by number. In the latter
case this package tries to maintain the number of the current
cartridge in a file and to (hopefully) keep it consistent
with the reality. In this case the cartridge handling system
must be configured to sequential mode (automatically putting
the next cartridge in, when the current one is ejected). The
pattern %c, if used in this command, will be replaced with
number of the current cartridge, %n with the number of the
next one, that is expected to be put into the streamer by a
robot in sequential mode. %b can be used instead of %c if
counting of cartridges starts with 0 and not with 1. The
same applies for %m, what means %n minus 1. %d is replaced
with the device name.
Init-Media-Command
The (shell-) command, the server runs before accessing the
storage media for the first time or after changing it. %d
will be replaced with the device. This command can be used
e.g. to automatically mount a removable disk after inserting.
This command might be called several times on the same media,
this has to kept in mind when configuring it. %n is replaced
with the number of the cartridge, that is expected to in the
drive, when the next media access operation will take place.
%m is replaced with %n - 1 i.e. assuming that the cartridge
numbering starts with zero, not one. Note, that the cartridge,
that will really be in the drive is not necessarily known at
the time, the Init-Media-Command is running. Thus the term
"expected". For more pattern replacements see: Status-file
Erasetape-Command
The (shell-) command to run, if the tape must be erased.
(currently not needed).
For pattern replacements see: Status-file
Tape-Full-Command
The (shell-) command to run, when a tape is full. %d is
replaced with the device name, %c with the number of the
cartridge, that became full, %n with the number of cycles,
the cartridge has become full until now and %C with the
full path to the configuration file. For more pattern
replacements see: Status-file
User To Inform
If you don't have a cartridge handling system (robot), a
human maintainer must put the appropriate cartridge into the
tape device. If you supply a mail program, an e-mail is sent
to the user given here, which informs him, that and which
cartridge (by number) must be put into the tape device.
If a timespan is configured, after that an automatic e-mail
should be sent due to an unaccessible tape device, it is
directed to this user (see Device-unavail-send-mail-after-min)
Mail-Program
The mail program used to send messages to a human maintainer.
This is done, whenever another cartridge must be put into the
tape device and it can't be done automatically (by a robot or
whatever). If you don't want to type the username again here,
you can instead write %u . The pattern %U will be replaced with
the login name of a current user on the client side, %H with
the name of the client host. If none could be figured out, the
entire word containing %U or %H is deleted from the command.
If you don't want mails to be sent, you may instead supply any
other command, that reads the standard input and does something
reasonable with it, e.g. redirects it to the console:
cat > /dev/console
For more pattern replacements see: Status-file
Var-Directory
The directory, where varying files should be put in. These
files should not be deleted. The information they contain is
necessary for the server to work properly
Tape-Pos-File
In this file some values are stored, e.g. the number of the
cartridge currently placed inside the streamer device. For
pattern replacements see: Status-file
Logging-file
Logging information concerning errors or other notable events
is redirected to this file. If the first word of this entry
is starting with @, then logging is directed to the syslog as
well. If there are characters immediately following the @,
this word is used as the syslog identifier, otherwise the
identifier is afbackup. If writing to the syslog is configured,
the rest of the entry is used as additional logging file, if
present. For more pattern replacements see: Status-file
Status-file
The current status of the server is written to this file. If
it starts with >>, then the file is created and status messages
will be appended to it. Otherwise the file is removed before
writing.
%L will be replaced with the full path of the lib-directory
of the server, %B with the bin-directory, %C with the config
directory and %V with the var-directory.
Lock-file
To prevent the server program from being started several times
a lock file is created and this is it's name. For pattern
replacements see: Status-file
Encryption-Key-Files
Entries specifying files, that contain encryption keys for
authenticating backup clients to the server. Each entry
consists of a filename, optionally followed by a colon : and
a specifier for client selection. If an entry lacks a client
selector, this one will apply for all clients, that are not
matched by any other entry. The client selector is either a
list of comma-separated hostnames, a filename starting with
a slash / containing hostnames one per line, or a command
starting with a bar, that is stripped off before starting
the command. The command gets the current client name as
input on stdin, aside from arguments containing patterns
(see below). If the command returns an exit status of 0,
the client name will match the entry. Entries are separated
by whitespace. If an entry must contain whitespace, it must
be enclosed by double quotes. If colons are needed within
the filenames, they must be escaped using a backslash. Each
key file must contain at least 5 characters and must not
have read permission for group or world. The pattern %H is
replaced with the client name resolved from the IP-address.
%h is similar to %H, but everything from and including the
first dot is stripped off. For more pattern replacements see:
Status-file.
Program-Directory
If you are using the remote start option for backing up
clients, this is the directory, where programs must reside,
that can be started remotely. No other programs can be
started remotely (for security reasons). For pattern
replacements see: Status-file
Init-Command
Here you may supply a (shell-) command to be run, when the
backup server side wakes up, i.e. the server process starts.
A %p appearing in this command is replaced with the name
of the client, that connected the backup service.
For more pattern replacements see: Status-file
Exit-Command
Here you may supply a (shell-) command to be run, when the
backup server side goes to sleep, i.e. the server process ends.
A %p appearing in this command is replaced with the name
of the client, that connected the backup service.
For more pattern replacements see: Status-file
Client configuration parameters
-------------------------------
BackupHosts
These are the hostnames of the machines where a server side
of the backup service resides. Some kind of streamer device
must be connected to these machines. The files and directories,
that should be saved, are packed, eventually processed somehow,
and then sent to the named machines, who writes them to the
connected device. The named machines are tested for service
availability. If a server is busy, the next one is tried.
BackupPorts can be configured in the same order as the host
entries supplied here. The servers in this list may be
separated by whitespace and/or commas. If a backup server
is the same host as the client, the use of the name localhost
is encouraged.
BackupPorts
These are the port numbers on the backup server machines, where
the backup server processes listen. The default is 2988 or the
number found in the file /etc/services (or in NIS if it is
configured). Several ports can be supplied, positionally according
to the backup server hosts supplied in the BackupHosts parameter.
The numbers can be separated by whitespace and/or commas. If
fewer numbers are supplied than backup servers, the default port
2988 applies for the rest. If more port numbers are given, the
superfluous ones are ignored.
CartridgeSets
The cartridge sets on the server side to use for backups.
They must bes legal number between 1 and the number of cartridge
sets configured on the appropriate server side. Several sets can
be supplied, positionally according to the backup server hosts
supplied in the BackupHosts parameter. The numbers can be separated
by whitespace and/or commas. If fewer numbers are supplied than
backup servers, the default set # 1 applies for the rest. If more
cartridge set numbers are given, the superfluous ones are ignored.
RootDirectory
This is the directory, the backup client changes to before
packing the files and directories. Their names should be
supplied relative to this directory, e.g. ./home .
DirsToBackup
These are the names of files and directories, that should be
saved. Wildcards in the usual manner are allowed (shell-
style or glob-style). They should be supplied relative to
the working directory, the client changes to when starting.
Descending into directories can be limited to the current
filesystem by preceding the filename with the four characters
.//. or the option -m (and a space). The prefix .//. is
stripped off the name before saving. Supplying a filename
preceded with the four characters /../ (what makes no sense
normally) or the option -r (and a space) forces the file
contents to be saved regardless of the file type. This way
raw partitions or similar things can be saved. The prefix
/../ is stripped off the name before saving. These file
contents are by default never processed for safety reasons.
If you want to force processing nonetheless, use //../ as
prefix or precede the name with the option -R (and a space).
To save the output of a command, supply (in double quotes) a
triple bar |||, followed by a space and the command. Another
triple bar must follow, after that another command doing the
opposite of the first one. This command gets the data written
by the first one as input at restore time. A triple sharp ###
and a comment may follow.
A command can be supplied here, whose output is read and used
as if it were written here literally. If this is desired, the
entry must start with a bar |, followed by a mandatory space
and the shell-command to execute. If the pattern %T appears
in this command, it is replaced with a specifier for the type
of backup: F, if it's a full backup; F<N>, if the full backup
is split into several parts with <N> being the part number,
e.g. F2; I, if it's an incremental backup; L<N> for a level <N>
backup e.g. L5
DirsToBackupX
These are the names of files and directories, that should
be saved as part X. Wildcards in the usual manner are
allowed (shell-style or glob-style). They should be
supplied relative to the working directory the client
changes to when starting (See: RootDirectory). Descending
into directories can be limited to the current filesystem by
preceding the filename with the four characters .//. or
the option -m (and a space). The prefix .//. is stripped
off the name before saving. Supplying a filename preceded
with the four characters /../ (what makes no sense normally)
or the option -r (and a space) forces the file contents to
be saved regardless of the file type. This way raw
partitions or similar things can be saved. The prefix /../
is stripped off the name before saving. These file contents
are by default never processed for safety reasons. If you
want to force processing nonetheless, use //../ as prefix
or precede the name with the option -R (and a space). To
save the output of a command, supply (in double quotes) a
triple bar |||, followed by a space and the command. Another
triple bar must follow, after that another command doing the
opposite of the first one. This command gets the data written
by the first one as input at restore time. A triple sharp ###
and a comment may follow.
A command can be supplied here, whose output is read and used
as if it were written here literally. If this is desired, the
entry must start with a bar |, followed by a mandatory space
and the shell-command to execute. If the pattern %T appears
in this command, it is replaced with a specifier for the type
of backup: F, if it's a full backup; F<N>, if the full backup
is split into several parts with <N> being the part number,
e.g. F2; I, if it's an incremental backup; L<N> for a level <N>
backup e.g. L5
These parameters may only be supplied if the parameter
NumBackupParts is set greater than 1 (!). Otherwise they must
be commented out to prevent a mismatch.
ReportProgress
Write the current progress to the file progress located in
the directory with the varying files (see: VarDirectory).
The first number in this file is the sum of file sizes
currently written to backup plus an estimate for the packer
overhead. The second number is the total sum of file sizes
to be written to backup plus estimated overhead, determined
in advance before doing the real backup. The third number
is the percentage of backup volume written up to now. All
the numbers do NOT include the volume of any command output
to be written to backup, because it would be necessary to
run the command(s) twice then, what is normally not desired.
Using this option requires the backup client to run over all
configured directories to be saved to determine the backup
volume in advance before doing the real backup, what might
be considered a waste of time and/or fileserver load.
FilesToSkip
These are the names of files, that should not be saved.
Wildcards in the usual manner are allowed (shell-style or
glob-style, furthermore path-patterns in the style of GNU's
find program with option -path. Note, that e.g. a*d matches
ab/cd). E.g. it does not usually make much sense to back up
object files, as they can be easily reproduced from existing
program sources.
DirsToSkip
These are the names of directories, that should not be saved.
Wildcards in the usual manner are allowed (shell-style or
glob-style, furthermore path-patterns in the style of GNU's
find program with option -path. Note, that e.g. a*d matches
ab/cd). E.g. it does not usually make much sense to back up
the lost+found directory or such only containing object files,
as they can be easily reproduced from existing program sources.
FilesystemTypes
A list of filesystem types, separated by whitespace and/or
commas. The type names can be prefixed with a plus, what is
identical with no prefix, with a dash - or a slash / . No
prefix or a plus means, that only files in filesystems of
the given type are saved, no others. A minus means, files in
a filesystem of the named type are not saved, nonetheless
such filesystems are traversed to search for filesystems of
other types probably mounted underneath. The slash means,
that such filesystems are not even entered or traversed
ExcludeListFile
A file with the name supplied here can be present in any
directory. It should contain a list of file-/directory-names
(or glob-style patterns), that should be skipped during backup.
Each entry must be in an own line. The given names/patterns are
valid only in the same directory, where the file resides. Thus
each directory can have it's individual exclusion list.
WriteChecksums
This flag specifies whether CRC32 checksums are written to
the backup or not. Checksumming costs performance but might
be desired to achieve additional safety, that recovered the
files are intact
UseCTime
When this flag is set, not only a filesystem entry's modification
time (mtime) is evaluated when selecting objects to store during
incremental or a level X backup, but also the inode change time
(ctime). In this mode the filesystem entries access time (atime)
is not restored to the value it had before saving it, because
that would again change the ctime, thus each incremental backup
would result in a full backup
NumBackupParts
If you have to backup a large amount of files and the
full backup can't be done during one run (e.g. over a
weekend), you can divide the full backup into pieces.
This number determines how many pieces you need. If
this number is not equal to 1, you have to supply which
files and directories you want to save in which piece.
You do so by setting the parameters DirsToBackupX with X
equal to the number of the backup part the files belong
to.
ProcessCmd
If you want your files to be processed during save (e.g.
compressed), you can supply the name of the program that
should perform the desired processing here. If you do so,
you MUST also supply the appropriate unprocess- program.
Note that this program may be specified with options but
no shell-like constructions such as pipes, variables or
wildcards. This program must read standard input and write
to standard output. For pattern replacements see Logging File
UnprocessCmd
The counterpart to the processing program. You must either
supply both process- and unprocess-program or neither of
them. Like the process program, the unprocess-program must
read standard input and write to standard output. For pattern
replacements see Logging File.
BuiltinCompressLevel
A number, that specifies the level of built-in compression, if
present, otherwise no built-in compression will be performed.
If a process program is also specified, the order of processing
is: First the data is piped through the external program and
then built-in compression is done. Uncompressing works the other
way round.
IndexFilePart
The name of the file where the names of the saved files
are stored. The current number is appended to this filename.
The number is incremented each time a full backup starts.
For pattern replacements see LoggingFile.
IndexProcessCmd
The program to preprocess the index file, in most cases some
kind of compression. If this parameter is not set, it defaults
to the setting of the ProcessCmd. If you set it, you MUST also
supply the appropriate unprocess- program. Note that this program
may be specified with options but no shell-like constructions
such as pipes, variables or wildcards. This program must read
standard input and write to standard output. For pattern
replacements see LoggingFile
IndexUnprocessCmd
The counterpart to the index processing program. If not given,
it defaults to the setting of the UnprocessCmd. You must either
supply both process- and unprocess-program or neither of them.
Like the index process program, the unprocess-program must read
standard input and write to standard output. For pattern
replacements see LoggingFile
ProcessBackupedFiles
This flag specifies whether the files that are saved,
should be processed by the configured program.
ProcessLogfiles
This flag specifies whether the filename logging files
should be processed by the configured program.
DoNotProcess
These patterns or filenames specify files, that no processing
is attempted on. Normally this is done for all files. This
might be inefficient, e.g. compressing files, that are already
compressed, so their compression can be suppressed with this
parameter. The value of this parameter must be a list separated
by whitespace. Double quotes may enclose list elements.
NumIndexesToStore
This number determines how many log files of previous full
backups are saved. These files may serve for the restore
of older files than those present in the current backup.
Of course there must be sufficient space to hold all the
data for the backups. It doesn't help to save all the saved
filenames but not to have them available on tape.
DaysToStoreIndexes
Instead of the number of index files to be kept (previous
parameter), their maximum age can be configured in days
(floating point number allowed). Older index files will
be automatically removed. If this parameter is configured
and the previous one at the same time, the longer duration
will be applied to avoid accidental removal of indexes on
configuration errors.
NumIndexesToScan
This is the maximum number of index files, that will be
scanned during restore. This can be helpful, if it takes
too much time to scan through all index files, what is
done, if restrictions are given, such as before time, after
time or certain tapes. This parameter can be overridden by
option -N of afrestore.
DaysToScanIndexes
Instead of configuring the maximum number of index files
to be scanned (previous parameter), their maximum age in
days can be configured (floating point number allowed).
This parameter can be overridden by option -O of afrestore.
CheckRestoreAccessPerms
When this flag is set, during restore started by a normal
user (not the superuser) it is checked, whether the user
has sufficient access permissions in the directory, where
the files are recovered. When relocating using option -C
this is default behaviour. With this flag set it will be
enforced also when not relocating. This has pros and cons.
It might be desirable, that users can also restore their
own files in directories owned by root (e.g. at-job files
or the CDE calendar stuff). On the other side this might
be considered a security problem.
LoggingFile
The name of a file error messages or other notable events
are written to. A dash - stands for no logging. The pattern
%V will be replaced with the full path to the var-directory,
%B with the bin directory, %L with the lib directory, %C with
the configuration directory and %I with the logging directory
(usually == %V)
ClientIdentifier
The identifier for the client. Default: The official hostname.
This entry is required, it several afbackup clients reside on
one host and the multi stream server is used. In this case the
multi stream server must be able to distinguish the clients to
distribute the pieces of backup data on tape correctly.
Otherwise the data would be mixed up and be unusable for the
reading client.
The multi-stream server writes the data to backup piecewise to
tape, each chunk preceded with an identifier. This identifier
is by default the official hostname of the connected client.
If several client programs are running on the same client
host, this procedure must fail. Any data prefixed with the
name of the client would be delivered to the client program
when reading (restore, verify, ...) and thus be a mixture of
data previously sent to the server by both client programs
with the same identifier (official hostname by default).
For this reason the server denies to serve several connected
clients with the same identifier. If several afbackup clients
should be installed on one host, different client identifiers
must be set in their configuration files.
VarDirectory
The directory, where varying files should be put in.
These files must not be deleted. The information they
contain is necessary for restore.
Lock-file
To prevent client programs from being started several times
a lock file is created and this is it's name. For pattern
replacements see: LoggingFile
EncryptionKeyFile
The file containing the encryption key for authenticating
the backup client to the server. This file must contain at
least 5 characters and must not have read permission for
group or world. For pattern replacements see LoggingFile.
StartupInfoProgram
This is the (shell-) command to run to save the startup
information of an incremental or full backup, sometimes
called bootstrap information. This program should read the
standard input and do something reasonable with it, e.g.
append it to some file. The produced information can be
used to recover from a hard crash, when the files are
lost, that are containing the names of the saved files.
Therefore this information should not be saved locally on
the client host, but e.g. on an NFS-mounted filesystem, a
floppy disc or in a mail-file (then this command should
be sth. like: mail someuser). For pattern replacements
see LoggingFile.
InitProgram
A (shell-) command to be run before a backup is attempted.
If this program returns an exit status unequal to 0, no
backup is performed. This parameter makes only sense when
backup is started remotely, cause in that case no shell-
command can be supplied. If backup is started locally, there
is no problem to run whatever is necessery before the backup
explicitly. For pattern replacements see LoggingFile.
ExitProgram
This parameter may specify a (shell-) command to run at
exit time of a full or incremental backup. The following
patterns are replaced as explained:
%l by the name of the file containing the filelists
%r by the name of the file containing statistics (this
file is automatically removed after execution of this
program)
%e by the overall exit status
%i with the minimum restore information
For more pattern replacements see LoggingFile.
Under very troublesome circumstances (e.g. several clients are
trying to connect a busy single stream server and timeout, or a
client program is killed) it might happen, that the ExitProgram
is not executed. If you rely on the actions of the ExitProgram
you better implement the desired functionality outside of the
afbackup system.
