Rsnapshot

rnapshot is an excellent backup application and has been around for a long time and is extremely stable.

Why are backups important? Well, hardware failures, accidental file deletion(s), files become corrupted, etc.. Backups can help recover data where applications are being updated/upgraded. Enough reasons?

Where should backups be stored? Due to the inevitable failure of hardware it is desirable to store backups on a separate system from where the production data is stored. Or possibly to an external medium such as an external USB disk drive. This article discusses backing up to an external USB drive.

Please Note:

rnapshot depends on attributes that are unique to Linux/Unix (i.e. ext3, ext4) filesystems only. If backups to "CIFS" (Samba a.k.a. smb, fat, fat32, vfat, ntfs) filesystems are required a different backup application must be used (i.e. rdiff-backup).

Here is a good book that discusses backups, recoveries, rsnapshot and rdiff-backup: "Backup & Recovery: Inexpensive Backup Solutions for Open Systems, by W. Curtis Preston".

Preparing an External USB Drive

Off-the-shelf external USB drives normally are setup to work with computers that utilize CIFS type filesystems. rsnapshot uses a "hard links" feature that is unique to Linux/Unix filesystems (ext3). "Hard Links" are not supported on filesystems such as: "smbfs", "Samba (SMB)", "FAT", "FAT32", "NTFS", "CIFS", "vfat". "Amahi Greyhole" mounts Amahi shares that look like "local disk drives" but these are Samba (SMB) mounted shares. The external disk drive will have to be prepared for a Linux/Unix filesystem, in particular ext3. Why? ext3 has been around for sometime, is stable, and "Windows" computers have Open Source drivers that can be installed to gain access to an ext3 drive.

The external drive can be setup for ext3 as follows:

You need to format (ext3, ext4) an external USB disk drive for rsnapshot to work.

umount /media/yourdisklabel

mkfs -t ext3 -v -L usbdisk /dev/sdb1

THIS WILL ERASE ALL DATA ON /dev/sdb1, MAKE SURE THIS IS YOUR USB DRIVE AND NOT ANOTHER DRIVE

Install rsnapshot

yum install rsnapshot

mkdir -p /media/usbdisk/.private/.snapshots

chmod 0700 /media/usbdisk/.private/

chmod 0755 /media/usbdisk/.private/.snapshots/

Quick rsnapshot Recipe

Here is a quick recipe to configure rsnapshot.

These are the critical settings in /etc/rsnapshot.conf:

    snapshot_root   /mnt/1tb-external/snapshots/
    interval        daily   14
    interval        weekly  4
    interval        monthly 4

This will create a series of directories called daily.0 through daily.13 weekly.0 to weekly.3 ... etc.

Another example of rsnapshot configuration on amahi 5.1

In this example automated backups are made to an external usb drive. Plug in the USB drive, it will probably mount automatically under /media/yourdisklabel

First login as root in a terminal (putty or ssh root@hda) and type

mount

in the output, find which device is your usbdrive, possibly /dev/sdb1

Mount your usbdisk permanently

To Mount your usbdisk permanently (so the backup will work after a reboot) do the following:

cp /etc/fstab /etc/fstab_bak

nano /etc/fstab

Add to this file

LABEL=usbdisk /media/usbdisk ext3 defaults 0 0

Save the file.

Modify rsnapshot configuration

nano /etc/rsnapshot.conf

make the following modifications to the file rsnapshot.conf for blank spaces use TABS!

snapshot_root /media/usbdisk/.private/.snapshots/

no_create_root 1

interval hourly 6

interval daily 7

interval weekly 4

interval monthly 12

verbose 3

backup /var/hda/files/docs/ localhost/

backup /var/hda/files/pictures/ localhost/

backup /var/hda/files/movies/ localhost/

backup /var/hda/files/music/ localhost/

backup /var/hda/files/othersharesyoumade localhost/

Save the file

rsnapshot configtest

this should return: syntax OK

Email reporting

for email reporting on your backups:

cp /usr/share/doc/rsnapshot*/utils/rsnapreport.pl /root

chmod 744 rsnapreport.pl

Automate backup with cronjob

crontab -l > cronjobs

nano cronjobs

add to this file for running rsnapshot and a weekly email report on rsnapshot:

0 */4 * * * /usr/bin/rsnapshot hourly 2>&1 | /root/rsnapreport.pl > /root/rsnapreport

30 23 * * * /usr/bin/rsnapshot daily

00 23 * * 1 /usr/bin/rsnapshot weekly

30 22 1 * * /usr/bin/rsnapshot monthly

00 22 * * 6 /usr/bin/rsnapshot du >> /root/rsnapreport | nail –r "somereturnadress@provider.com" -s"HDA backup report" -S smtp=smtp.yourprovider.com youremail@provider.com < /root/rsnapreport

Save the file

crontab cronjobs

Rsnapshot should now be operational.

Make your backups available on clients (READ ONLY)

If you want to make the backups accesible from your clients:

Create a //hda/backup share in the HDA webinterface

chkconfig nfs --level 2345 on

add a read only NFS export:

nano /etc/exports

add

/media/usbdisk/.private/.snapshots/ 127.0.0.1(ro,no_root_squash)

Save file

Unfortunately mounting an NFS share in fstab did not work on my machine after a reboot, so I chose an alternative configuration that mounts the share later in the booting process:

nano /etc/rc.local

Add

mount -r -t nfs localhost:/media/usbdisk/.private/.snapshots/ /var/hda/files/backup/

save file