andyleonard.com – zfs-snapshot.sh

Here’s a nice script found on thinking sysadmin. I slightly modified it to use the real mount point instead of assuming “/”, my changes are highlighted below:

#!/usr/local/bin/bash
# FROM: http://andyleonard.com/2010/04/07/automatic-zfs-snapshot-rotation-on-freebsd/

# Path to ZFS executable:
ZFS=/sbin/zfs

# Parse arguments:
TARGET=$1
SNAP=$2
COUNT=$3

# Function to display usage:
usage() {
scriptname=`/usr/bin/basename $0`
echo "$scriptname: Take and rotate snapshots on a ZFS file system"
echo
echo " Usage:"
echo " $scriptname target snap_name count"
echo
echo " target: ZFS file system to act on"
echo " snap_name: Base name for snapshots, to be followed by a '.' and"
echo " an integer indicating relative age of the snapshot"
echo " count: Number of snapshots in the snap_name.number format to"
echo " keep at one time. Newest snapshot ends in '.0'."
echo
exit
}

# Basic argument checks:
if [ -z $COUNT ] ; then
usage
fi

if [ ! -z $4 ] ; then
usage
fi

# Get the TARGET mountpoint
TARGET_MOUNT=$($ZFS get -H -o value mountpoint $TARGET)

# Snapshots are number starting at 0; $max_snap is the highest numbered
# snapshot that will be kept.
max_snap=$(($COUNT -1))

# Clean up oldest snapshot:
if [ -d ${TARGET_MOUNT}/.zfs/snapshot/${SNAP}.${max_snap} ] ; then
$ZFS destroy -r ${TARGET}@${SNAP}.${max_snap}
fi

# Rename existing snapshots:
dest=$max_snap
while [ $dest -gt 0 ] ; do
src=$(($dest - 1))
if [ -d ${TARGET_MOUNT}/.zfs/snapshot/${SNAP}.${src} ] ; then
$ZFS rename -r ${TARGET}@${SNAP}.${src} ${TARGET}@${SNAP}.${dest}
fi
dest=$(($dest - 1))
done

# Create new snapshot:
$ZFS snapshot -r ${TARGET}@${SNAP}.0

Thanks Andy!

Useful tools in an “embedded” FreeNAS: wget and bash

wget

To install wget on a “data” parition:

export PKG_TMPDIR=/mnt/usb-data/temp
pkg_add -r wget -P /mnt/usb-data/pkg

Now we need a script to create the symlinks to the wget binaries in the “pkg” directory:

nano /mnt/usb-data/hooks.sh

Here’s the content:

#!/bin/sh

ln -s /mnt/usb-data/pkg/bin/wget /bin/wget

Now make it run at boot time, go in System —> Advanced —> Command scripts and enter:

/mnt/usb-data/hooks.sh

Select PostInit and that’s it! Everytime you reboot your FreeNAS server the symlinks will be re-created!

bash

For bash, add this in the “hooks.sh” script:

# .bashrc for root
ln -s /mnt/usb-data/bashrc /root/.bashrc

# .bashrc for regular user
ln -s /mnt/usb-data/bashrc /mnt/.bashrc

# automatically load bash for root on login (not clean but works)
echo "bash --init-file /mnt/usb-data/bashrc" >> /root/.cshrc

# automatically load bash for regular user on login (not clean but works)
echo "bash --init-file /mnt/usb-data/bashrc" >> /mnt/.cshrc

Vim (Vi IMproved) in an “embedded” FreeNAS

You need an embedded install with a data partition. My FreeNAS server runs from a 1GB usb stick and the data partition is mounted as “/mnt/usb-data”. To install Vim on the usb stick:

# using csh
setenv PKG_TMPDIR /mnt/usb-data/temp

# install package
pkg_add -r vim-lite -P /mnt/usb-data/pkg

Now we need a script to create the symlinks to the Vim binaries in the “pkg” directory:

nano /mnt/usb-data/hooks.sh

Here’s the content:

[bash]#!/bin/sh

# Vim symlinks to binaries
ln -s /mnt/usb-data/pkg/bin/vim /bin/vi
ln -s /mnt/usb-data/pkg/bin/vim /bin/vim

# .vimrc for root
ln -s /mnt/usb-data/pkg/share/vim/vim72/vimrc_example.vim /root/.vimrc
# .vimrc for regular user
ln -s /mnt/usb-data/pkg/share/vim/vim72/vimrc_example.vim /mnt/.vimrc

# syntax file
mkdir /usr/local/share/vim/
mkdir /usr/local/share/vim/syntax/
ln -s /mnt/usb-data/pkg/share/vim/vim72/syntax/syntax.vim /usr/local/share/vim/syntax/syntax.vim[/bash]

Now make it run at boot time, go in System —> Advanced —> Command scripts and enter:

/mnt/usb-data/hooks.sh

Select PostInit and that’s it! Everytime you reboot your FreeNAS server the symlinks will be re-created!