Simple RSYNC/SSH/ZFS Backup

Hi there,

It has been a while, busy building clouds and stuff. In the Christmas spirit of sharing, today I wanted to share this bash script for ZFS backups, it will basically snapshot the ZFS share, RSYNC new files over and the delete the old ZFS snaps.

Simple, yes, but somehow a wheel that keeps being reinvented over and over again, so here’s my version of it. Hope it helps someone save some time.

For this script, the backup server is one of our own TerraNas servers (basically, Ubuntu 14 with Native ZFS and NFS/4) the client is a Ubuntu14 LTS server, the SSH keys have been imported to the client so we can SSH across without passwords and such.

On the ZFS/NFS server side, we disable ID mapping to have usernames cross the wire instead of ID’s

echo N > /sys/module/nfs/parameters/nfs4_disable_idmapping

share the ZFS drive with:

zfs set sharenfs=rw=@,insecure,no_root_squash pool1/backup

Where is your subnet or host of course.

Then we share it our with zfs share -a and service nfs-kernel-server restart.

We do have one export to the localhost in the /etc/exports file, because NFS will complain if this file is empty, but the rest of the exports come from ZFS

On the client we have this little script:

Continue reading “Simple RSYNC/SSH/ZFS Backup”

Mass Update Ubuntu (debian) servers without puppets or chefs

Ok, you do not want in invest the exorbitant fee for management and scripting though some fancy web based script engines like Puppet or Chef, but like us you so have this farm of a couple of dozen (or hundreds) of VM’s that at some point need their updates and patches, especially when these VM’s have been neglected for a couple of weeks during the summer vacations :).

Now how to go about this?

Firstly from your admin server or PC, copy your SSH cert to the target so that you can log in without password challenge, for this to work under root you need to give root a password, (log in as root on the target server sudo, and set a password with passwd) of course not advised, but very practical in most cases. 

Now to copy your ssh cert, simple issue the ssh-copy-id command followed by uid@ip (e.g. root@ and authenticate.

Now make a file with IP’s (or hostnames) of the servers you want to manage, i call it servers.lst 

Then this little (very simple) script does the trick

while read name

echo “Processing : ” $name
ssh -n $name “DEBIAN_FRONTEND=noninteractive $1”
done < servers.lst

the -n after ssh makes ssh wait before it returns to shell, the DEBIAN_FRONTEND=noninteractive in the command suppresses some debconf warnings (as explained here)

Simply make executable (chmod +x) and run as ./ ‘apt-get update && apt-get upgrade –yes’ (for example)

Sometimes, less is more..

VMware tools on Ubuntu 12.04 LTS from Repository

Task for today, equip a couple of dozen VM’s with VMware Tools. I hate manual labor so I hacked up this little script.

Make sure current VMware tools or open-vm tools are uninstalled and purged otherwise this will crap out.

# Fetch the key

apt-get install python-software-properties –yes
apt-key add

# Add the Repo to APT, and remove sources (we remove all sources, but you can specify to remove only
# VMware sources (since they are not published and will end up in an error)

apt-add-repository ‘deb precise main’ && wait
# We dont want any sources by default
sed -i ‘s/deb-src/#deb-src/g’ /etc/apt/sources.list


# Install the tools

apt-get update &&
# Check Kernel version, we use 12.04 LTS ONLY, esx-nox is NO GFX support, as it should be
apt-get install vmware-tools-esx-kmods-3.2.0-23-generic vmware-tools-esx-nox –yes &&
apt-get upgrade –yes && wait


Ce’st ca, all done.

Local Ubuntu Mirror

We were getting tired of our Ubuntu servers reaching out to the internet every day/week to fetch updates and patches. Man if you thought Windoze was bad, these Ubuntu servers know their way around consuming bandwidth as well. So in the Windoze world we had something called WSUS (if it is still called that?) so I wanted something similar to keep roughly 150+ servers from going out to fetch their bits.

The APT-MIRROR package to the rescue. Setup is quite easy, but i did not find any ‘cook book’ that fitted all my needs.

First off I need to store these mirrors on a nice de-duplicated NFS server (Nexenta/ZFS) to keep it from consuming to many GB’s. So what we did is create a NFS export on one of our SAN’s with root access for the Mirror server, simple enough.

On the server side

On the server we install APT-MIRROR with a simple apt-get command;

apt-get install apt-mirror

This installs the package and creates the structure in /var/spool/apt-mirror

Now we mount our NFS mount-point to the /var/spool/apt-mirror/mirror from the FSTAB in the usual way

<hostname>:/volumes/pool1/mirror /var/spool/apt-mirror/mirror nfs auto,noatime,nolock,bg,nfsvers=3,intr,tcp,actimeo=1800 0 0

(yes, our NFS is still V3, since it serves some ESXI hosts as well)

Now it is time to configure our /etc/apt/mirror.list, we ended up with

############# config ##################
set base_path /var/spool/apt-mirror
set mirror_path $base_path/mirror
set skel_path $base_path/skel
set var_path $base_path/var
set cleanscript $var_path/
set postmirror_script $var_path/
set run_postmirror 1
set nthreads 10
set _tilde 5
set defaultarch amd64

############## end config ##############

deb precise main restricted universe multiverse
deb precise-security main restricted universe multiverse
deb precise-updates main restricted universe multiverse
deb precise-proposed main restricted universe multiverse
deb precise-backports main restricted universe multiverse
deb precise main main/debian-installer restricted restricted/debian-installer universe universe/debian-installer multiverse multiverse/debian-installer


Now how did we decide to go for to fetch our mirror, for us this was the best performing (not necessarily closest) mirror that is up-to-date. A way to determine your fastest mirror is with the handy netselect tool. how to install and use;

First fetch the latest binary (at time of writing 0.3.ds1-25


Then throw it against the mirror lists from launchpad, and add some grep magic to make the output readable

netselect -v -s10 -t20 `wget -q -O- | grep -P -B8 “statusUP|statusSIX” | grep -o -P “(f|ht)tp.*\”” | tr ‘”\n’ ‘ ‘`

For us it came back with the Hong Kong Chinese University and some others, the Taiwan repo was at the 3rd place, We decided to use the Taiwan one since the Hong Kong archives tend not up to date, maybe we should open up ours to have an up-to-date repo down one here 🙂 . Anyway, you should verify your results against the mirror list on to get your close and up to date repo.

It is now time to do a first time population of the repository by manually executing

apt-mirror -c apt-mirror

This can take some time as we will pull down

Now the newly downloaded repo can be made available through a web server of choice (Apache for us). We just linked the ubuntu folder to the /vat/www, we could also share the folder out as an RSYNC repo on the Nexenta storage server, maybe at a later time, not today.

ln -s /var/spool/apt-mirror/mirror/ /var/www/ubuntu

Now all that is left to do on the server side is to add the update script to your cron tab for scheduled execution, this is made easy as the package provides this schedule file in /etc/cron.d/apt-mirror, the only thing you need to do there is to uncomment the line

On the Client Side

On the client side we need to edit the /etc/apt/sources.list. Here we commented every deb repo and left the deb-src pointing to the us repositories. Then on the top of the file we added the deb repe’s for our own mirror.

deb http://<domain>/ubuntu precise main restricted universe multiverse
deb http://<domain>/ubuntu precise-security main restricted universe multiverse
deb http://<domain>/ubuntu precise-updates main restricted universe multiverse
deb http://<domain>/ubuntu precise-proposed main restricted universe multiverse
deb http://<domain>/ubuntu precise-backports main restricted universe multiverse

#deb precise main restricted
deb-src precise main restricted
#deb precise-updates main restricted
deb-src precise-updates main restricted
#deb precise universe
deb-src precise universe
#deb precise-updates universe
deb-src precise-updates universe
#deb precise multiverse
deb-src precise multiverse
#deb precise-updates multiverse
deb-src precise-updates multiverse
deb-src precise-backports main restricted universe multiverse
#deb precise-backports main restricted universe multiverse
#deb precise-security main restricted
deb-src precise-security main restricted
#deb precise-security universe
deb-src precise-security universe
#deb precise-security multiverse
deb-src precise-security multiverse

now run an apt-get update / apt-get upgrade, and all should be coming from your own repo

As always, hope this helps someone save time, if it does not work out for you, pleaee  leave a comment and we’ll try to help where possible

– Fault