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Re: Which FS to use ?



Willem.Smit@sanlam.co.za wrote:

Hey guys (are there any girls on this list - hmm)
Which filesystem would you recommend for a biggish (10 gig) partition ? At
the moment I'm using Ext2fs and I really have to use something else, it's
just way to slow. So should i use Reiser or Ext3fs ? Or is there maybe
another fs I can use ?

In what areas of use does the Ext2 FS on your 10GB drive seem "way to slow"?
Transferring a file from one folder to another?
With only one disk you're copying from disk, to MB and writing back to the same disk - not the speediest of disk operations normally. It would help to know if this partition contains all of Debian or if it is just one mount like /home and if the rest of Debian is on the same disk or another disk

Reading files off the disk?
Linux nicely pre-fetches data beyond your read request anticipating that you are going to need that data, thus speeding disk reads by reducing the need to move the head around. Severely fragmented files may not have their data within that read-ahead section and miss out on that potential performance gain. Files that are always appended to (like some tar files, directories that keep getting new entries, or system logs) are very likely to fragment. Files that are re-written get a clean slate and are not fragmented. Once the kernel reads something it keeps it in memory if possible since that is much faster. If you don't have much free memory, you are missing out on that gain as well. I don't know if the Resier FS handles fragmentation of appended files better, but any file system will appear to work faster on cached data if you have oodles of memory.

Some other situation?
Maybe the disk/controller isn't using DMA? What type of disk is it?

I haven't used much of anything outside of ext*, so I can't give an experiance based comment on Reiser. It's suppose to be pretty fast and good at handling lots of small files and directories.

The place where ext3 orders of magnitude faster than ext2 is when you boot up after an improper shutdown/unmount. ext3 (which is basically ext2 with journaling) can safely skip fsck for the most part. Ext2 you get to sit there watching the file systems scan away. The bigger your hard disk, the longer you'll sit and the faster ext3 would seem. :) In other cases, because ext3 is writing it's journal to a disk every few seconds, it could be a little slower. Since most systems aren't normally under intense I/O, this is usually unnoticable. You do have the option of storing the journal to a different disk.

Ok, I've hit the end of any helpfull thought on the subject, now for some related ponderings:

I've read people suggesting to not use ext3 over ext2 on some directories (which means different mounts for those directories.) I think they talked about places like /var/spool/news but I could be very wrong.

Maybe /etc would be better served by a Reiser FS.

Jacob



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