Guida al Backup Centralizzato con Amanda

Amanda è un tool di backup che permette di effettuare il backup di più server linux e windows da una sola macchina con la possibilità di ricevere rapporti via e-mail e poter usare come supporto anche un masterizzatore.

Primi Passi

Installiamo tutto ciò che ci servirà sul server (cioè la macchina con installata l'unita nastro)

Da shell:

sudo apt-get install -y amanda-client amanda-server smbfs smbclient inetd

Ora andiamo a creare i file che userà il programma

sudo vi /etc/amandahosts

che dovrà avere una struttura come la seguente:

localhost backup
localhost root
nomeserver      backup
nomeserver      root

successivamente:

sudo vi /etc/amanda/DailySet1/exclude.gtar

Questo era il file delle cartelle da escludere, potremmo scriverci:

tmp
lost+found
/var/spool/amanda/
*.mp3
/home/danoncopiare

ora:

sudo touch /etc/amanda/DailySet1/tapelist.amlabel

sudo touch /etc/amanda/DailySet1/tapelist.yesterday

sudo touch /etc/amanda/DailySet1/tapelist

Ora:

sudo vi /etc/amanda/DailySet1/disklist

Disklist è l'elenco delle cartelle da copiare, noi potremmo scriverci:

nomeserverhttp /var/apache  comp-user-tar
nomeserver /etc  comp-user-tar
nomeserversamba /home comp-user-tar
nomeclient /home/utente/filedacopiare

Ora:

sudo vi /etc/amanda/DailySet1/amanda.conf

Questo è il file di configurazione del set di backup che stiamo creando scriveteci:

#
# amanda.conf - sample Amanda configuration file.  
#
# If your configuration is called, say, "DailySet1", then this file
# normally goes in /etc/amanda/DailySet1/amanda.conf.
# 
# for explanation of the parameters refer to amanda(8) and
# /usr/doc/amanda/WHATS.NEW.gz 

org "Società"   # your organization name for reports
mailto "root@domain.com"                # space separated list of operators at your site
dumpuser "backup"                       # the user to run dumps under
#
inparallel    4         # maximum dumpers that will run in parallel
netusage  15000         # maximum net bandwidth for Amanda, in KB per sec
maxdumps      2

# a filesystem is due for a full backup once every <dumpcycle> days
dumpcycle 5 days        # the number of days in the normal dump cycle
tapecycle 5 tapes       # the number of tapes in rotation

bumpsize 500 MB         # minimum savings (threshold) to bump level 1 -> 2
bumpdays     1          # minimum days at each level
bumpmult     2          # threshold = bumpsize * (level-1)**bumpmult

#runtapes     9         # explained in WHATS.NEW
#tpchanger "no-changer" # the tape-changer glue script, see TAPE.CHANGERS
tapedev "/dev/nst0"     # Linux @ tuck, important: norewinding
# tapedev "/dev/nrst8"  # or use the (no-rewind!) tape device directly

tapetype SLR7           # what kind of tape it is (see tapetypes below)
labelstr "Backup[0-5]"  # label constraint regex: all tapes must match

diskdir "/var/spool/amanda/tmp"         # where the holding disk is
disksize 5000 MB                        # how much space can we use on it
#diskdir "/dumps/amanda/work"   # additionaly holding disks can be specified
#diskdir "/mnt/disk4"
#disksize 1000 MB               #       they are used round-robin


# Amanda needs a few MB of diskspace for the log and debug files,
# as well as a database.  This stuff can grow large, so the conf directory
# isn't usually appropriate.

infofile "/var/lib/amanda/BckSet/curinfo"       # database filename
logfile  "/var/log/amanda/BckSet/log"           # log filename

# where the index files live
indexdir "/var/lib/amanda/BckSet/index"

# tapetypes
#
# Define the type of tape you use here, and use it in "tapetype" above.
# Some typical types of tapes are included here.  The tapetype tells amanda
# how many MB will fit on the tape, how big the filemarks are, and how
# fast the tape device is.
#
# For completeness Amanda should calculate the inter-record gaps too, but it
# doesn't.  For EXABYTE and DAT tapes this is ok.  Anyone using 9 tracks for
# amanda and need IRG calculations?  Drop me a note if so.

#define tapetype HP {
#    comment "just produced by tapetype prog (hardware compression off)"
#    length 19442 mbytes
#    filemark 76 kbytes
#    speed 1760 kps
#}
define tapetype SLR7 {

    comment "Produced by tapetype program-TANDBERG SLR7"
    length 18549 mbytes
    filemark 1034 kbytes 
    speed 1470 kps 

}
define tapetype SLR75 {

    comment "Produced by tapetype program-TANDBERG SLR75"
    length 39005 mbytes
    filemark 256 kbytes
    speed 1721 kps

}
# dumptypes
#
# These are referred to by the disklist file.  The dumptype specifies
# certain "options" for dumping including:
#       index           - keep an index of the files backed up
#       compress-fast   - (default) compress on the client using fast algorithm
#       compress-best   - compress using the best (and slowww) algorithm
#       no-compress     - don't compress the dump output
#       srvcompress     - Compress dumps on the tape host instead of client
#                         machines.  This may be useful when a fast tape host
#                         is backing up slow clients.
#       record          - (default) record the dump in /etc/dumpdates
#       no-record       - don't record the dump, for testing
#       no-hold         - don't go to the holding disk, good for dumping
#                         the holding disk partition itself.
#       skip-full       - Skip the disk when a level 0 is due, to allow
#                         full backups outside Amanda, eg when the machine
#                         is in single-user mode.
#       skip-incr       - Skip the disk when the level 0 is NOT due.  This
#                         is used in archive configurations, where only full
#                         dumps are done and the tapes saved.
#       no-full         - Do a level 1 every night.  This can be used, for
#                         example, for small root filesystems that only change
#                         slightly relative to a site-wide prototype.  Amanda
#                         then backs up just the changes.
#
# Also, the dumptype specifies the priority level, where "low", "medium" and
# "high" are the allowed levels.  These are only really used when Amanda has
# no tape to write to because of some error.  In that "degraded mode", as
# many incrementals as will fit on the holding disk are done, higher priority
# first, to insure the important disks are dumped first.

define dumptype always-full {
    comment "Full dump of this filesystem always"
    options no-compress
    priority high
    dumpcycle 0
    maxcycle 0
}

define dumptype comp-user-tar {
    program "GNUTAR"
    comment "partitions dumped with tar"
    options compress-best, index, exclude-list "/etc/amanda/exclude.gtar"
    priority medium
}

define dumptype hq-comp-user-tar {
    program "GNUTAR"
    comment "partitions dumped with tar"
    options compress-best, index, exclude-list "/etc/amanda/BckSet/exclude.gtar"
    priority medium
    dumpcycle 0
    maxcycle 0
}


define dumptype hq-incr-user-tar {
    program "GNUTAR"
    comment "partitions dumped with tar"
    options compress-best, index, exclude-list "/etc/amanda/BckSet/exclude.gtar"
    priority medium
    dumpcycle 3 
    maxcycle  4
}

define dumptype comp-root-tar {
    program "GNUTAR"
    comment "Root partitions with compression"
    options compress-fast, index, exclude-list "/etc/amanda/exclude.gtar"
    priority low
}

define dumptype user-tar {
    program "GNUTAR"
    comment "partitions dumped with tar"
    options no-compress, index, exclude-list "/etc/amanda/exclude.gtar"
    priority medium
}

define dumptype high-tar {
    program "GNUTAR"
    comment "partitions dumped with tar"
    options no-compress, index, exclude-list "/etc/amanda/exclude.gtar"
    priority high
}

define dumptype root-tar {
    program "GNUTAR"
    comment "Root partitions dumped with tar"
    options no-compress, index, exclude-list "/etc/amanda/exclude.gtar"
    priority low
}

define dumptype comp-user {
    comment "Non-root partitions on reasonably fast machines"
    options compress-fast
    priority medium
}

define dumptype nocomp-user {
    comment "Non-root partitions on slow machines"
    options no-compress
    priority medium
}

define dumptype holding-disk {
    comment "The master-host holding disk itself"
    options no-hold
    priority medium
}

define dumptype comp-root {
    comment "Root partitions with compression"
    options compress-fast
    priority low
}

define dumptype nocomp-root {
    comment "Root partitions without compression"
    options no-compress
    priority low
}

define dumptype comp-high {
    comment "very important partitions on fast machines"
    options compress-best
    priority high
}

define dumptype nocomp-high {
    comment "very important partitions on slow machines"
    options no-compress
    priority high
}

define dumptype nocomp-test {
    comment "test dump without compression, no /etc/dumpdates recording"
    options no-compress, no-record
    priority medium
}

define dumptype comp-test {
    comment "test dump with compression, no /etc/dumpdates recording"
    options compress-fast, no-record
    priority medium
}

Bene abbiamo quasi finito la preconfigurazione, dobbiamo ora aggiungere in /etc/crontab le seguenti righe:

0 16 * * 1-5    /usr/sbin/amcheck -m DailySet1
45 0 * * 2-6    /usr/sbin/amdump DailySet1

Ora Amanda è installato nel sistema, facciamolo funzionare: