Need to know where to start with gfs2
Hi,
We've been asked to create a shared filesystem between 2-3 servers and NFS is too slow. I started looking at gfs2 but we have no experience working with Red Hat Clusters and there is a ton of documentation out there. Can anyone point me to a doc to help me get started that would allow me to set up a shared filesystem between these boxes? They are on Red Hat 6.4. Thanks.
Mary Kay
Responses
Hi Mary,
Unfortunately setting up GFS is a fairly involved process and can typically include things you don't normally have to deal with (switch multicast configuration, fencing, etc...)
What application are you using that requires a shared file system? The reason I ask is that they will often make recommendations, or have alternatives for a shared-FS.
I guess the good news is that Red Hat Cluster is one of the easier platforms to setup and manage, once you have the base requirements addressed ;-)
For other folks that might have a similar question:
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Global_File_System_2/index.html
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Fence_Configuration_Guide/index.html
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/High_Availability_Add-On_Overview/index.html
Is this for file sharing or block level storage? Have you looked into GlusterFS?
http://www.gluster.org/
Like James stated above. GFS is fairly complex not only to deploy as there are quite a few 'moving pieces' but also to maintain, tune and troubleshoot. That is no knock on GFS2. My current shop runs it for critical production systems. It is quite robust and rich in stability and features.
If you're interested in Gluster, you can also check out Red Hat Storage, which is the Red Hat solution derived from the upstream Gluster project.
I agree with David,
If you aren't emotionally attached to GFS to solve this problem, can I suggest looking into GlusterFS for a shared filesystem between multiple hosts. I have configured it in a similar scenario where we found NFS performance lacking and as a result setup GlusterFS across the nodes that needed to access the filesystem and the performance was dramatically improved.
The learning curve is a little steep at the start (configuring / concepts) with GlusterFS but no worse that GFS and it provides great performance when it's up and running.
The application is Tibco and they provided a list of technologies that they will support and GlusterFS isn't one of them so I have to stick with GFS2. Seems a bit more complicated than I wanted though since all I need to do is share 1 filesystem. Unfortunately, NFS isn't an option because it has to be able to do file locking on the NFS server side and our NFS solution is EMCs Isilion and they won't support that. So at this point, I've told the application team that we need a professional services engagement (per the advice of our Red Hat technical rep) to get this properly configured.
Read our High Availability and GFS2 product documentation. It's written by the developers who actually write and maintain the cluster software, it's really good.
The community cluster wiki is also pretty good - https://alteeve.ca/w/Main_Page - it's got a great overview of components and sets you in the right "frame of mind" for working with clusters. Be aware that its tutorial does suggest components like DRBD which are not supplied or supported by us, so don't follow it to the letter if you wish to be fully supported by Red Hat.
You do need to do a significant amount of reading and research here. The cluster software isn't something you can setup in a hurry and expect to work fine. However, when it's configured correctly it's very reliable. Setup at least one test cluster so your first deployment isn't your production deployment. We can do an architecture review for you before you deploy to production.
The most important thing to learn is how GFS2 works with locking, and how your workload will interact with that locking. Long story short: If you have a lot of concurrent read then GFS2 will probably work well for you. If you have a lot of concurrent write, then your workload is not suitable for GFS2 and will perform poorly.
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