==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.
Voglio premettere che amanda è si un software molto utile ma altrettanto rigido, infatti amanda prima esegue il backup su cache (bumpsize), e successivamente lo copia nel tape.
Amanda numera in oltre le cassette dando un'etichetta come da file di configurazione, per tanto andranno inserite una alla volta e "etichettate" con l'apposito comando.
Nel caso mancasse la cassetta nel tape o fosse quella sbagliata, verrà inviata una mail, e il backup rimarrà nella cache (che aumenterà se non vuotata prima del successivo backup mediante l'apposito comando amflush) per tanto insisto nel ricordare di UTILIZZARE AMANDA SOLO SE CONSAPEVOLI, ma in tal caso è un tool eccellente.
esempio di caratteristiche di amanda; nel caso vogliate recuperare un determinato file sarà lei a segnalarvi quale cassetta inserire e a segnalarvi la possibilità di versioni più o meno recenti in altre cassette.
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 postfix
Verificate l'apposita guida alla configurazione di un server di posta.
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:
Vorrei far notare che in questo file dovrete adattarlo inserendo una sezione (se non presente) per le dimensioni del vostro tape e settare i dump, l'email e i dati necessari, studiate le righe commentate per non sbagliare.
#
# 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:
Dobbiamo sempre ricordare che tutti i comandi di amanda adranno eseguiti dall'utente creato automaticamente BACKUP quindi per procedere con i comandi daremo:
su backup
in costruzione...
