@pacharest: New cluster to be deployed very soon. #VMWARE & #SMART_NETWORK (#PUPPET #DRBD #ZABBIX #SNORT)
Tag Archive - drbd
automatic & dynamic launch of new ‘branch’ systems (xen dom0), without having to do anything more than to rack them (no OS install needed, can be upgraded by rebooting them),
high redundancy at the leaf level (xen domU, automatic migration toward less used dom0),
failure resistace through bonded interface, multi-path & multi-host fiberchannel SAN & controller…
Cutting-edge of Cloud Computing
Just got off the bus in Montreal, Québec. This is a lightning visit, in 48 hours, I’ll be back in my office in Ottawa. But, right now, I’m taking a drink in one of my favorite downtown coffee shop and I’m planning.
The next few hours will see little sleep and lots of action ; More precisely I’ll be deploying lots of hardware (2 IBM SAN, 2 core servers, 2 switchs, 2 APC, 5 branchs servers – supporting up to 20 ‘leaf’/virtual servers), and then somes (3 couples of 2 systems in high redundancy (wackamole IP ‘fencing’, shared-storage through DRBD). All that will go in ‘my’ new 48U cage @Hypertec (old nortel building) to act as a demo for some clients.
Once that’s completed, the true fun start: A very big part of this infrastructure is going to be self-healing, failure resitant and high performance. We are speaking of :
This is going to be solid, scalable, fast : the holy grail of a lot of service provider that are aiming at automatization of their ‘hosting’ business. The result of a lot of planning and testing ; the cutting-edge of cloud-computing.
It is clichée – I know.
I know it is so much of a cliché to write a blog post about why you haven’t update in quite some times – but I can’t stand not writing anything.
Putting so much time in my enterprise (Les Laboratoires Phoenix) also took me away from some very interesting project ; such as DRBD-8.3 releases. It now allows stacked resources – meaning that you can have 3 (maybe more?) nodes in your setup. This is a very good news and make this release the next thing that goes through my labs.
There is so much to do! Got at least 3 big projects for cloudweavers, the social/community aspect of my corp. Haven’t had any time to draft some press release but just yesterday, 2 lucky dev. got free access to brand new servers – for their apps, sites, and codes. I am now hosting around 6 projects on those servers and it will be growing very fast next month.
Btw, there’s going to be a new photos posted today. Garanti ou argent remis!
drbd_selector.sh
Here is a quick bash code snippet. It allows the execution of code/scripts on a server with a Primary drbd array.
It does not take into account that there can be more than one array, or that split-brain scenario exist, or that the script might be not-executable, or …
I’m really posting that because I get to use it quite often and always forget ‘how I did it last time’… the search function on this blog is kinda nice ;-).
if [ $(grep st:Primary /proc/drbd | wc -l) = 1 ] ;
then $@ ;
fi
glusterfs & synchronous data storage
Labs: installation & configuration of GlusterFS as synchronous data storage solution.
By: Pascal Charest, Freesoftware consultant
Date: September, 2008.
Synchronization of files in a cloud environment is a challenge in the path of high-{availability, performance}. From simple load balanced web sites to full-blown applications – some files always need to be in sync. Peoples, for simplicity, rely on asynchronous transfer (ie: rsync ), others deploy bigger solutions (ie: block device replication through DRBD or shared storage through AoE protocol & concurrency management with OCFSv2) or even go for the “lazy” “no-shared-storage” solution through NFS.
To address this problem in the PraizedMedia software stack, I decided to give FUSE based GlusterFS a try. Awesome, really ! The technical knowledge to deploy a basic solution is very very low. The modularity of the program also help to have “something working right now”. This isn’t meant as a direct alternative to DRBD or a good SAN deployment but in my use case, it fit perfectly.
In this lab, I will guide you through the installation of GlusterFS on 2 networked systems. They will be both used as “servers” & “client” for the GlusterFS filesystem. They will be sharing a directory (on both system : /var/production/brick), re-mounted as /var/production/static through GlusterFS. Any write I/O on this directory (of any client server) will be synchronized to the pool. This last feature is called “AFR” (for automatic file replication) and is a module (called a translator) to the GlusterFS file system.
The specificity of my environment is around the file-locking management : I don’t need any. By design, the application will never try to write the same file twice on any of the server.
#Installation of requirement (standard tools)
apt-get install flex bison libfuse-dev linux-headaers-`uname -r` curl
#download of the sources
cd /usr/local/src/
curl -O http://ftp.zresearch.com/pub/gluster/glusterfs/1.3/glusterfs-CURRENT.tar.gz
tar zxf glusterfs-CURRENT.tar.gz
# configure
cd glusterfs-1.3.11
./configure --prefix=/usr/local/glusterfs-1.3.11
make && make install
ln -s /usr/local/glusterfs-1.3.11 /usr/local/glusterfs
So we now have a basic 2 servers GlusterFS systems installed. Lets be honest, that wasn’t really hard! We are still missing configuration files though.
#Editing /usr/local/glusterfs/etc/glusterfs/glusterfs-server.vol
#
# glusterfs-servers definition
# volume definition are on first lvl, other are on second lvl (tabbed)
volume brick
type storage/posix
option directory /mnt/production/brick
end-volume
volume server
type protocol/server
option transport-type tcp/server
option auth.ip.brick.allow *
subvolumes brick
end-volume
#Editing the /usr/local/glusterfs/etc/glusterfs/glusterfs-client.vol
#
# glusterfs-client.vol
# volume definition are on first lvl, other are on second lvl (tabbed)
#
volume remote1
type protocol/client
option transport-type tcp/client
option remote-host 002.praized.com
option remote-subvolume brick
end-volume
volume remote2
type protocol/client
option transport-type tcp/client
option remote-host 001.praized.com
option remote-subvolume brick
end-volume
volume mirror0
type cluster/afr
subvolumes remote1 remote2
end-volume
#Launching services (servers and clients)
mkdir -p /mnt/production/brick
/usr/local/glusterfs-1.3.11/sbin/glusterfsd -f /usr/local/glusterfs-1.3.11/etc/glusterfs/glusterfs-server.vol
mkdir -p /mnt/production/static
/usr/local/glusterfs-1.3.11/sbin/glusterfs -f /usr/local/glusterfs-1.3.11/etc/glusterfs/glusterfs-client.vol /mnt/production/static/
You now possess a synchronized directory between your two systems. Please note that GlusterFS require TCP/6996 port to be open. There is also some improvement that can be done to this setup through adding a locking mechanism & i/o thread – I don’t currently need them, but you might.
Enjoy!
Debugging notes ; after starting the server process you should have a kernel process call glusterfs. All log files are in /usr/local/glusterfs/var/log/glusterfs*. After starting the client, “df -h” should show you your new mount point. Careful with UID/GID (&Permission), there is no such thing as root_squash_fs in GlusterFS yet.
Other notes ; Using Amazon EBS would have been the perfect solution if they did allow multiple servers-volume mount and lets us deal with concurrency / lock problems. But, they don’t.