I collected together some settings for the VFS & harddrive-tweaking,
could you please test it & say if it improves battery runtime for you / improves throughput during data copying
(I've taken some of those from ubuntuforums, wikis, and several other places: kudos to all of your "tuners" out there
/proc/sys/vm/mapped <-- is the opposite of /proc/sys/vm/swappiness == mapped -> 100-swapped (ck-patchset / zen-sources specific)
# enhancing battery runtime (you may need to run sync manually for data safety's sake)
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#!/bin/bash
# Tweak virtual memory to conserve power when running on batteries.
echo 100 > /proc/sys/vm/mapped
echo 0 > /proc/sys/vm/dirty_expire_centisecs
echo 0 > /proc/sys/vm/dirty_writeback_centisecs
echo 60 > /proc/sys/vm/dirty_background_ratio
echo 95 > /proc/sys/vm/dirty_ratio
echo 40 > /proc/sys/vm/vfs_cache_pressure
for i in /sys/class/scsi_host/host*; do
/bin/echo "min_power" > $i/link_power_management_policy
done
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#!/bin/bash
# Tweak virtual memory for running on AC.
echo 66 > /proc/sys/vm/mapped
echo 3000 > /proc/sys/vm/dirty_expire_centisecs
echo 3000 > /proc/sys/vm/dirty_writeback_centisecs
echo 10 > /proc/sys/vm/dirty_background_ratio
echo 95 > /proc/sys/vm/dirty_ratio
echo 100000 > /proc/sys/vm/vfs_cache_pressure
for i in /sys/class/scsi_host/host*; do
/bin/echo "max_power" > $i/link_power_management_policy
done
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for i in /sys/block/sd*; do
/bin/echo "256" > $i/queue/read_ahead_kb
done
for i in /sys/block/sd*; do
/bin/echo "anticipatory" > $i/queue/scheduler
done
## seems to be set dynamically, at least for me
#for i in /sys/block/sd*; do
# /bin/echo "256" > $i/queue/nr_requests
# done
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mkfs.reiser4 -o create=ccreg40,compress=lzo1 /dev/foo Thanks in advance for your feedback
this post will be updated to reflect the changes in performance I experience.
I'll also add the addresses I stumble upon so that you can put together your ultimate tweaking / performance settings.
please share those with the community and post them here
Thanks in advance
References / Links:
throughput:
Extreme Linux Performance Monitoring and Tuning 1.0 Tuning ...
Reduced Power Usage (wiki.ubuntu.com)
Intel G33, Q35 and Q33 Chipsets
kernel tuning
lrz Munich (linux computing center Munich)
linux ata faq
searchenterpriselinux.techtarget.com tip
raid optimization
responsiveness:
Tales from responsivenessland: why Linux feels slow, and how to fix that


