Posted by
ryuzaki0
on from the yes-even-more-sgi-news dept.
hedonick wrote in to let us know that SGI will be releasing XFS under the terms of the GPL. It looks like they want to use it to replace ext2 under Linux. Since XFS is a journaling filesystem, this is something I'm personally looking forward to.
experience with XFS and JFS
by
jetson123
·
· Score: 3
I have been using XFS and JFS-based systems for several years and I'm unimpressed.
I have more experience with JFS because I have used it in some large applications; I have been running XFS on my desktop Irix machine for a couple of years.
Here are some observations about JFS; most of those also apply to XFS:
It can be quite slow in practice; for example, untarring a large amount of scientific data, JFS took three times as much time as ext2, even though it was running on a faster SCSI disk. I haven't done XFS measurements, but XFS also feels sluggish in practice to me.
It only protects file system structure, not file content.
It only protects against a small set of failures. For example, hardware failures and file-system related bugs still cause data loss.
JFS comes with a LVM (volume manager) and XFS integrates XLV. In my experience, those kinds of systems complicate disk management, increase the risk of file system management mistakes, and make it more difficult to predict performance.
Journalling does not guarantee fast recovery. There may still be extensive recovery going on at boot time. IBM's JFS, ironically, often runs on systems that have (unrelated) performance bottlenecks in their boot code that makes them some of the slowest booting UNIX machines in existence.
The only time I have actually lost a partition over the last decade was on a journalling file system due to, what appears to have been a software bug in the fs code. Journalling file systems are tricky pieces of software to write.
Of course, with XFS on Linux, we can finally compare these issues side-by-side on identical hardware and kernels. It will be interesting how XFS holds up.
XFS has some nice features, and I think it will be a great addition to Linux as an optional file system. Its availability will make Linux much more attractive to some corporate buyers.
But before adopting it widely, I believe the issues that I raise above need to be looked into and evaluated carefully. I suspect many people don't need the features of XFS, overestimate the safety of journalling file systems, and will get bitten by the complexities and overhead. I hope XFS will not preempt the further development of "traditional" Linux file systems.
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I have more experience with JFS because I have used it in some large applications; I have been running XFS on my desktop Irix machine for a couple of years.
Here are some observations about JFS; most of those also apply to XFS:
Of course, with XFS on Linux, we can finally compare these issues side-by-side on identical hardware and kernels. It will be interesting how XFS holds up.
XFS has some nice features, and I think it will be a great addition to Linux as an optional file system. Its availability will make Linux much more attractive to some corporate buyers.
But before adopting it widely, I believe the issues that I raise above need to be looked into and evaluated carefully. I suspect many people don't need the features of XFS, overestimate the safety of journalling file systems, and will get bitten by the complexities and overhead. I hope XFS will not preempt the further development of "traditional" Linux file systems.