[Gluster-users] Questions from an Ignoramus

[Doug Schouten]

Hi all,

I am a grad student setting up a new cluster in our research group. We 
already have five nodes each with 5 x 1 TB disks in a RAID-5 array. 
Currently we just export this disk using NFS (/cluster/data0[1-5]). This 
is already kind of bothersome because one needs to remember which of 
five NFS mounts contains a dataset of interest.

Now we are getting four new nodes with faster disk (12 x 600 GB array, 
each @ 15K RPM), and would like to merge these (at least) into a global 
filesystem, and even possibly add the existing disk.

GlusterFS looks very promising, especially because it doesn't need to 
take over the filesystem, and the configuration looks relatively simple 
(compared to GPFS or Lustre).

However, I am having trouble tracking down a detailed explanation of how 
it works, so that I can see where the weak-points are. The installation 
guide on the Wiki was a good starting point to get a very basic 
understanding, but I am totally unaware of a detailed explanation of 
configuration options &c.

Does some sort of manual exist?

Also, how robust is GlusterFS? We probably want to stripe the data to 
improve performance, but if a server dies, does the file catalogue go 
with it, resulting in total data loss? Or does the meta-data get 
replicated somehow so that one can recover the partial files?

Any helpers, including pointers to existing configurations that I can 
learn from would be ideal.

kind regards,
Doug Schouten

p.s. to describe our needs more fully, our data-sets consist of many 
files on the order of 100 - 200 MB in size. Typically we write files 
once (retrieve from a central collaboration server) and read many times 
as we tune an analysis, so read speed is much more important than write 
performance. Redundancy is not a huge concern, since most of our data is 
replicated at remote sites anyway ... although stability is still a 
consideration because re-fetching the data takes O(days). The machines 
are connected by dual-bond 1Gb ethernet. Latency is probably not an 
issue since they are all connected on an internal switch in the same rack.