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Mon, 28 Jan 2008

Is Lustre dead after Sun's acquisition?

It looks so.

First, because new (1.8) release, which will see the light this summer, will run as a userspace application (I want to highlight, that it is a parallel (!) high-performace (!!) filesystem (!!!)) on top of ZFS, which is slow (and a high-end test: zfs is faster than ufs only in single setup, which says how bad solaris vfs cache is, although it is a speculation only) filesystem, designed and first implemented in Sun, then ported to Linux via zfs-fuse project.

Userspace zfs runs slower than kernel one in most cases, actually it is faster than kernel zfs only in single test and difference is close to error rate (about 5-8%). Sun posted that tests to lustre-devel couple of months ago.

Second, because kernel support of Lustre (it is based on ext3) is "too complex" for Sun, and thus will be dropped after 2.0 release (end of the year):

... because it removes the burden of having to maintain kernel patches for Linux. The encumbrance of kernel patches has made development and debugging of Lustre considerably more complex than in user space; it has slowed our support for new Linux kernels and distros; and it's even been the source of some nasty regressions when unsupported kernel APIs changed from under us.

/devel/fs :: Link / Comments (2)

POHMELFS naming conversion and the first release date.

I've just decided, that POHMELFS will not use traditional versioning (1, 2, 3 or 0.1, 0.2 and so on) system, but completely new, related to its name.
As you probably know, POHMELFS stands for Parallel Optimized Host Message Exchange Layered File System, so it is very logical to use following naming converstion: 50 ml, 100 ml, 0.3l, pint, 0.5l, 0.7l, 1 liter and so on...

The first release is scheduled for this week. it will not include cache coherency algorithm implemented, but will have completely new and faster local cache.
Stay tuned!

/devel/fs :: Link / Comments (2)