journalling options [WAS: optimizing ext3...]
I've been trying to get somewhere with the below (seems easier to top
post this time - apols!) and have come across the "data=journal" mode
for ext3.
Has anybody had experience with this as opposed to "data=ordered"? good
or bad experiences?
Is it possible to change this on a live system
(http://www-106.ibm.com/developerworks/linux/library/l-fs8.html implies
it's something at mount time, only)?
Any other thoughts on why my system seems to creep to a crawl whenever
there's IO (eg compressing a file, creating a tar, running progs with
big (a couple Gb) files)?
Thanks, MIchael
On Fri, 2005-05-06 at 11:45 +0100, michael wrote:
> I've Googled about but not found anything to help although I'm sure
> there must be a relevant HowTo/FAQ somewhere, so all pointers welcome!
>
> My system is a dual Xeon box, running Sarge with
> michael@ratty:~/.personal$ uname -a
> Linux ratty 2.4.27-1-686-smp #1 SMP Wed Dec 1 19:50:17 JST 2004 i686
> GNU/Linux
>
>
> and 1 250Gb disk partitioned thus
> michael@ratty:~/.personal$ df
> Filesystem 1K-blocks Used Available Use% Mounted on
> /dev/hde2 9614148 287684 8838088 4% /
> tmpfs 1034796 0 1034796 0% /dev/shm
> /dev/hde8 1829159 19364 1712202 2% /boot
> /dev/hde11 119765712 64309488 49372412 57% /home
> /dev/hde6 9614116 438828 8686916 5% /tmp
> /dev/hde5 9614116 1950684 7175060 22% /usr
> /dev/hde7 19228276 16042208 2209320 88% /usr/local
> /dev/hde3 9614148 1673012 7452760 19% /var
> michael@ratty:~/.personal$ mount
> /dev/hde2 on / type ext3 (rw,errors=remount-ro)
> proc on /proc type proc (rw)
> devpts on /dev/pts type devpts (rw,gid=5,mode=620)
> tmpfs on /dev/shm type tmpfs (rw)
> /dev/hde8 on /boot type ext3 (rw)
> /dev/hde11 on /home type ext3 (rw)
> /dev/hde6 on /tmp type ext3 (rw)
> /dev/hde5 on /usr type ext3 (rw)
> /dev/hde7 on /usr/local type ext3 (rw)
> /dev/hde3 on /var type ext3 (rw)
> usbfs on /proc/bus/usb type usbfs (rw)
>
> and the syslog shows each with
> May 4 19:32:15 localhost kernel: kjournald starting. Commit interval
> 5 seconds
> May 4 19:32:15 localhost kernel: EXT3 FS 2.4-0.9.19, 19 August 2002 on
> ide2(33,3), internal journal
> May 4 19:32:15 localhost kernel: EXT3-fs: mounted filesystem with
> ordered data mode.
>
> I was wondering if this 'default' setting is optimal, particularly
> for /home -- I frequently (circa daily) run jobs (Fortran code) each
> that creates files of a few Gb per run.
>
> It may or may not be connected but I have noticed, albeit only recently
> but that may not exclude it always happening, that `top` gives "system"
> from 10-40% when such jobs are running (or big data files in Mozilla or
> OpenOffice-Spreadsheet).
>
> If you need more info, please let me know, and if you have references
> for how to tune this definitely let me know!
>
>
>
>
> --
> Michael Bane
> Atmospheric Physics Group
> University of Manchester
>
>
--
Michael Bane
Atmospheric Physics Group
University of Manchester
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