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Re: disc cache, ramdisk, mm.

 

On Fri, Jun 15, 2007 at 07:57:48AM +0000, Troels Arvin wrote:
> Den Fri, 15 Jun 2007 08:37:37 +0200 skrev Mogens Kjaer:
> > 819200000 bytes (819 MB) copied, 3.70776 seconds, 221 MB/s
> [...]
> > 819200000 bytes (819 MB) copied, 0.395932 seconds, 2.1 GB/s
> 
> Bliver caching-effekten annulleret hos dig, hvis du afmonterer og 
> derefter genmonterer?
spock olsen banden # dd if=01-olsen\ banden.avi of=/dev/null
spock olsen banden # time dd if=01-olsen\ banden.avi of=/dev/null 
1432000+1 records in
1432000+1 records out
733184054 bytes (733 MB) copied, 2,04566 s, 358 MB/s

real    0m2.048s
user    0m0.234s
sys     0m1.813s
spock olsen banden # cd
spock ~ # umount /dev/vg/varlibsambaoutgoing 
spock ~ # mount /dev/vg/varlibsambaoutgoing 
spock ~ # cd /var/lib/samba/outgoing/olsen\ banden/
spock olsen banden # time dd if=01-olsen\ banden.avi of=/dev/null 
1432000+1 records in
1432000+1 records out
733184054 bytes (733 MB) copied, 5,40375 s, 136 MB/s

real    0m5.420s
user    0m0.262s
sys     0m2.993s

Det ser ud til at data ikke længere er i cache. Men jeg må sige det
undrer mig.

/kallenberg


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