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IBM's High Performance File System
HoosierPeschke writes "BetaNews is running a story about IBM's new file system, General Parallel File System (GPFS). The short and skinny is that the new file system attained a 102 Gigabyte per second transfer rate. The size of the file system is also astonishing at 1.6 petabytes (petabyte == 1,024 terabytes). IBM has up a page with more information and specs on the system.."
Is this stuff available in a fashion where we might see it ported for use on standard x86 hardware? Is it GPL'd? I want this in my living room!
-1 Uncomfortable Truth
We used GPFS in our production environment for about 9 months in 2004/2005. We chose it specifically because it allowed several machines to share the file system (like NFS) but with file locking. It was also supposed to be very fault tolerant with no single point of failure. We set it up using a fiberchannel SAN.
Unfortunately we had a lot of problems with it. For one, performance was quite bad in ceratin cases... doing an ls in a large directory would take a very long time. Doing finds would take a very long time. Once you had a specific file you wanted, opening and reading it was reasonable (though all disk ops were still on the slow side), but multi file operations lagged on the level of 10s of seconds or more. I think it was having to issue network checks to every machine in the set for each file or something.
Also, the CPU usage was very high across all our machines, primarly from lock manager communications. It really taxed the system. And perhaps worst of all, it would caused crashes sometimes. A single machine in the set would die (usually a GPFS assert), and though that didn't break the set permanently, a multi-minute freeze on all disk reads would take place until the set determined the machine was unavailable. We spoke with IBM about all this stuff... provided debugging output and everything, we used the latest patches. But we never got the issues resolved. It was a very rough few months indeed. I probably averaged 4 hours sleep per night.
When I say "slow" what am I comparing it to? In the end we switched to NFS and we came up with a somewhat clever way to avoid the need for file locking. NFS used the same SAN hardware, but had a single point of failure: the head server. We doubled up there with warm failover. The load on all servers dropped dramatically (I'm talking from ~40 load to ~.1 load). Disk operations were orders of magnitude faster. And we've not had a single NFS related lockup or failure in the past year and a half *knocks on wood*.
Anyways -- GPFS probably has some good uses. But I would not recommend it for a very high-volume (lots of files, lots of traffic) mission critical situation. Unless they've made some major improvements.
Cheers.