On Sat, Jun 30, 2001 at 08:29:04PM +0200, Jens Benecke wrote:
> Hi,
>
> I just had a, er, 'lively' discussion with someone claiming ReiserFS is
> crap because it hogs even the fastest CPU too much, and it uses 4x as much
> processing power to do metadata operations, and in general is slower
> because of the journal. My benchmarks don't reflect this, especially on
> current hardware (ATA-66 and ATA-100 disks on VIA chipsets).
>
> While I agree that the journal does create an additional overhead, I'd like
> to know if the CPU overhead is really that much. I've seen your benchmarks
> on the web site but they don't say anything about CPU useage.
Here's what happens when I rm a big directory tree on ext2 and reiserfs:
ext2 -- Disk trashes like mad. Forget accessing it while rm is running.
CPU usage is relatively low.
Reiserfs -- Light disk accesses with little seeking (can barely hear it,
LED blinks softly). Can do light jobs on the disk while rm
is running. CPU usage hovers between 65% and 95%.
OK, all those B* trees suck CPU cycles, and the journal means overhead,
but in my humble opinion it's worth it. Even with the CPU hogging, most
IO operations seem snappier to me on Reiserfs (at least compared to
ext2, can't say about XFS or JFS). And I'm not even talking of the more
efficient file packing.
You makes your choices, you lives with it ;)
Jean-Francois Landry
--
"In short, just as the Multics mentality of careful access controls
shows up throughout Unix, the cretinous CP/M mentality of uncontrolled
havoc shows up in DOS and all its mutant children."
--- Tom Christiansen
--
