UK Linux Conf

PaulJS writes "The UKUUG are holding a Linux Conference on 25th - 26th June 1999. Topics include GNOME (design decisions) and the ext3 filesystem which is a contender for the replacement for ext2. "

Comments

EXT3(?) vs XFS

[Michael Snoswell]

XFS is a lot more than "just" a journaling FS. One of it's other major components is guaranteed I/O rate partitions. When you create these special partitions, the OS tests the disk I/O rate then lets you specify up to the tested rate and then the OS will guarantee you the I/O rate you selected (can be less than the max), nomatter what the machine is doing (ie even under really heavy load, network, UI etc).

This sort of thing is needed when doing uncompressed cinema res images at 24fps (or HDTV) where you need 90-130Mbyte a sec from the disk nomatter what else is going on.

There's a cable channel using 24 odd uncompressed TV res video streams for live delay rebroadcasting (across time zones) using XFS. Works nicely.

Linux doesn't need this right now. Why? Because it's kinda obvious that the whole OS needs to be in on this act, it's not just a FS thing. True, the guaranteed rate stuff can be treated discretely (ie left out). But I think people may be naive when they say, "Yay, use XFS."

I haven't seen what EXT3 promises, but I bet that the current implementation of XFS has fingers going *deep* into IRIX that won't make it a fast retro fit into Linux, compared to EXT3 (unless EXT3 is just conjecture at this time, or only a modest improvement. This'll be why Linus wants a full rewrite: to get greatly improved performance will need a lot of changes on the OS side, and if you're going to go to that effort, you'd better make it worthwhile)

Linux does need a journaling FS and XFS may be the best bet, but it won't happen quickly unless SGI puts some serious resources behind it. For any other effort to pool together enough ppl for long enough to make it happen is just too unlikely for us to just sit around hoping for.

Also, just who has the resources to test large production systems (4+ CPUs) on an OS under test? Corporates, that's who. And they'll contribute their code to Open Source, right? Because...?

This *will* all happen, but I think some of these tougher OS issues will need corporate backing that may have a price current purists will not like but will have to accept (ie less than Open Source code licenses or maybe even (cringe!) binary drivers).

My 2 cents worth.