Maximum size of each GFS filesystem for RHEL3 (2.4.x kernel) is 2 TB, you can have multiple filesystems of that level. So, to get access to 10TB of data requires a minimum of 5 separate filesystems/storage combinations.
The theoretical 2.6 kernel limit is 16TB for 32bit platforms, and
Exabyte for 64bit platforms. There has been some talk on irc and the
mailing list about people trying those configurations but I have not
heard of any results as of yet.
I was trying to create a GFS filesystem greater than 2Tb on 2.6 and several people on this list kindly provided help to get some legacy code out of the mkfs.gfs stuff so I could create a filesystem bigger than 2Tb (8Tb). That worked but the next problem was that it wouldn't mount for some reason.
Unfortunately, I ran out of time to get it working and had to move on to other things. From what I saw then (about 2 months ago), GFS is scalable beyond 2Tb but it would probably take a while with the help of this list to get it working properly.
Stephen
