Hi,

I have two disks on a CentOS 5.4 web server. The second hdc is an exact image of hda. hdc is mounted successfully in fstab. I want to use rsync to back up files from hda6 (/var) to hdc (also /var).

My question is should I use the rsync --delete option? Seems like I should but I'm scared to.

Thanks.

Er.. yes?

rsync -a --delete /var /mount_point_of_hdc/

If you're nervous, run it without --delete but with -v and make sure what happens is what you expect.

Well, it lists bunches of files that will be deleted on the destination, but if they are not on the source, I'd think it's OK. Thill a bit nervous though. There is stuff here I know nothing about and stuff that just plain scares me like "deleting account/" and "deleting mail".

Thanks.

*** Launching RSYNC command (simulation mode):
rsync -r -n -t -p -o -g -x -v --progress --delete --ignore-existing -l -H /var/amavis/ /mnt/backup/var/

sending incremental file list
./
deleting yp/binding/
deleting yp/nicknames
deleting yp/
deleting www/usage/webalizer.png
deleting www/usage/usage_201001.html
deleting www/usage/usage.png
deleting www/usage/msfree.png
deleting www/usage/index.html
deleting www/usage/hourly_usage_201001.png
deleting www/usage/daily_usage_201001.png
deleting www/usage/ctry_usage_201001.png
deleting www/usage/
deleting www/mrtg/mrtg-ti.png
deleting www/mrtg/mrtg-ti.gif
deleting www/mrtg/mrtg-r.png
deleting www/mrtg/mrtg-r.gif
deleting www/mrtg/mrtg-m.png
deleting www/mrtg/mrtg-m.gif
deleting www/mrtg/mrtg-l.png
deleting www/mrtg/mrtg-l.gif
deleting www/mrtg/favicon.ico
deleting www/mrtg/
deleting www/manual/mod/mod_python/icons/up.png
<...>
deleting www/manual/
deleting www/icons/small/uu.png
<...>
deleting www/icons/
deleting www/html/
deleting www/error/include/top.html
<...>
deleting www/error/
deleting www/cgi-bin/
deleting www/
deleting virusmails/spam-zollSgHJUk7R.gz
<...>
deleting virusmails/
deleting spool/virtual/blabla.net/user/tmp/
deleting spool/virtual/
deleting spool/repackage/
deleting spool/postfix/trace/
<...>
deleting spool/postfix/
deleting spool/mail/rpc
<...>
deleting spool/
deleting run/wpa_supplicant/
<...>
deleting run/
deleting preserve/
deleting opt/
deleting nis/
deleting net-snmp/snmpd.conf
deleting net-snmp/
deleting named/slaves/
deleting named/data/
deleting named/pcrat.net
deleting named/num
deleting named/default
deleting named/
deleting lost+found/
deleting log/samba/
<...>
deleting log/
deleting lock/subsys/yum-updatesd
<...>
deleting lock/
deleting local/
deleting lib/yum/
<...>
deleting lib/
deleting gdm/:0.Xservers
deleting gdm/:0.Xauth
deleting gdm/.gdmfifo
deleting gdm/.cookie
deleting gdm/
deleting games/
deleting ftp/pub/
deleting ftp/
deleting empty/sshd/etc/localtime
deleting empty/sshd/etc/
deleting empty/sshd/
deleting empty/
deleting clamav/mirrors.dat
deleting clamav/main.cvd
deleting clamav/daily.cvd
deleting clamav/
deleting cache/yum/updates/packages/
<...>
deleting cache/
deleting amavis/var/
<...>
deleting amavis/
deleting account/pacct
deleting account/
deleting mail
amavisd.lock
amavisd.pid
razor-agent.log
.razor/
.razor/razor-agent.log
.razor/server.c301.cloudmark.com.conf
.razor/server.c302.cloudmark.com.conf
.razor/server.c303.cloudmark.com.conf
.razor/servers.catalogue.lst
.razor/servers.discovery.lst
.razor/servers.nomination.lst
.spamassassin/
.spamassassin/auto-whitelist
db/
deleting db/nscd/
deleting db/Makefile
db/__db.001
db/__db.002
db/__db.003
db/cache-expiry.db
db/cache.db
db/nanny.db
db/snmp.db
tmp/
tmp/amavis-20100125T225952-02777/
tmp/amavis-20100125T225952-02777/email.txt
tmp/amavis-20100125T225952-02777/parts/
tmp/amavis-20100125T230102-02778/
tmp/amavis-20100125T230102-02778/email.txt
tmp/amavis-20100125T230102-02778/parts/
tmp/amavis-20100127T190102-02884/
tmp/amavis-20100127T190102-02884/email.txt
tmp/amavis-20100127T190102-02884/parts/
tmp/amavis-20100127T200101-02885/
tmp/amavis-20100127T200101-02885/email.txt
tmp/amavis-20100127T200101-02885/parts/
tmp/amavis-20100204T220102-02700/
tmp/amavis-20100204T220102-02700/email.txt
tmp/amavis-20100204T220102-02700/parts/
tmp/amavis-20100204T230101-02701/
tmp/amavis-20100204T230101-02701/email.txt
tmp/amavis-20100204T230101-02701/parts/
tmp/amavis-20100214T130102-02873/
tmp/amavis-20100214T130102-02873/email.txt
tmp/amavis-20100214T130102-02873/parts/
var/

sent 1390 bytes received 166 bytes 3112.00 bytes/sec
total size is 945300 speedup is 607.52 (DRY RUN)

The delete option will create an exact copy of the source at the destination.
So if you delete a file on the source, it will be deleted on the destination also.
If you create a new file at the source, it will be created at the destination.