RaveMaker
Overview
How to set up a snapshot-style backup server on Linux using rsync and hard links, with SSH key authentication and NFS or CIFS mounts for remote sources.
Requirements
- Linux Server/Desktop backup manger (we’ll use CentOS and we’ll call it BackupServer) - Linux Servers/Desktops to backup (we’ll use CentOS and we’ll call it Source1) - SSH Connection - Root Access
Establish SSH connection without password between the BackupServer and Source1
Generate id_rsa, id_rsa.pub in the BackupServer:
ssh-keygen (do not use a password - just hit Enter)
Copy (and rename) id_rsa.pub to authorized_keys on Server
scp -r -P 22 /root/.ssh/id_rsa.pub Source1:/root/.ssh/authorized_keys
You can connect now as root between the servers without a password.
Mount source to backup
We will give an example of NFS but you can also use CIFS (SAMBA) mounts:
For NFS mount edit ‘/etc/fstab’ and add:
Source1:/vol1/ /source/vol1 nfs rsize=8192,wsize=8192,timeo=14,intr
Create a folder to mount:
mkdir /source/vol1
Phase 3: create the manager script files
Create /scripts/daily.sh:
#!/bin/sh
echo "Starting Daily Backup"
echo "Please Wait..."
SNAPSHOT_RW=/backup;
# step 1: delete the oldest snapshot, if it exists:
if [ -d $SNAPSHOT_RW/daily.5 ] ;
then
rm -rf $SNAPSHOT_RW/daily.5 ;
fi ;
# step 2: shift the middle snapshots(s) back by one, if they exist
if [ -d $SNAPSHOT_RW/daily.4 ] ;
then
mv $SNAPSHOT_RW/daily.4 $SNAPSHOT_RW/daily.5 ;
fi;
if [ -d $SNAPSHOT_RW/daily.3 ] ;
then
mv $SNAPSHOT_RW/daily.3 $SNAPSHOT_RW/daily.4 ;
fi;
if [ -d $SNAPSHOT_RW/daily.2 ] ;
then
mv $SNAPSHOT_RW/daily.2 $SNAPSHOT_RW/daily.3 ;
fi;
if [ -d $SNAPSHOT_RW/daily.1 ] ;
then
mv $SNAPSHOT_RW/daily.1 $SNAPSHOT_RW/daily.2 ;
fi;
# step 3: make a hard-link-only (except for dirs) copy of the latest snapshot, if that exists
if [ -d $SNAPSHOT_RW/daily.0 ] ;
then
cp -al $SNAPSHOT_RW/daily.0 $SNAPSHOT_RW/daily.1 ;
fi;
# step 4: rsync from the system into the latest snapshot (notice that
# rsync behaves like cp --remove-destination by default, so the destination
# is unlinked first. If it were not so, this would copy over the other
# snapshot(s) too!
rsync -va --delete --delete-excluded --exclude-from '/backup/exclude.txt' /eng/ $SNAPSHOT_RW/daily.0 ;
# step 5: update the mtime of daily.0 to reflect the snapshot time
touch $SNAPSHOT_RW/daily.0 ;
save the file and give execute permissions:
chmod +x /scripts/daily.sh
Create /scripts/weekly.sh:
#!/bin/sh
echo "Starting Weekly Backup"
echo "Please Wait..."
SNAPSHOT_RW=/backup;
# step 1: delete the oldest snapshot, if it exists:
if [ -d $SNAPSHOT_RW/weekly.3 ] ;
then
rm -rf $SNAPSHOT_RW/weekly.3 ;
fi ;
# step 2: shift the middle snapshots(s) back by one, if they exist
if [ -d $SNAPSHOT_RW/weekly.2 ] ;
then
mv $SNAPSHOT_RW/weekly.2 $SNAPSHOT_RW/weekly.3 ;
fi;
if [ -d $SNAPSHOT_RW/weekly.1 ] ;
then
mv $SNAPSHOT_RW/weekly.1 $SNAPSHOT_RW/weekly.2 ;
fi;
if [ -d $SNAPSHOT_RW/weekly.0 ] ;
then
mv $SNAPSHOT_RW/weekly.0 $SNAPSHOT_RW/weekly.1;
fi;
# step 3: make a hard-link-only (except for dirs) copy of
# daily.5, assuming that exists, into weekly.0
if [ -d $SNAPSHOT_RW/daily.5 ] ;
then
cp -al $SNAPSHOT_RW/daily.5 $SNAPSHOT_RW/weekly.0 ;
fi;
# note: do *not* update the mtime of weekly.0; it will reflect
# when daily.5 was made, which should be correct.
save the file and give execute permissions:
chmod +x /scripts/weekly.sh
Create /scripts/exclude.txt (optional - excludes folders you don’t need to backup):
MOVED
Moved
TrashCan
Expired
Manage automatic backups
For example run the ‘weekly.sh’ script every Saturday at 02:05 :
crontab -e
2 5 * * 0-5 /scripts/daily.sh
2 5 * * 6 /scripts/weekly.sh
This is an explanation of crontab:
| Minute | Hour | Day of Month | Month | Day of Week | Command |
|---|---|---|---|---|---|
| (0-59) | (0-23) | (1-31) | (1-12 or Jan-Dec) | (0-6 or Sun-Sat) |
Refrences: - http://www.mikerubel.org/computers/rsync_snapshots/