How to enable Direct memory access (DMA) on your SATA/IDE hard disk
Answer:
Execute the following command
# hdparm -d1 /dev/hda
Where hda is the first hard disk in your system.
Jan 172010
How to test the speed of your ATA hard disk
Answer:
With the help of hdparm command:
# hdparm -tT /dev/hda
/dev/hda:
Timing cached reads: 1352 MB in 2.00 seconds = 676.23 MB/sec
Timing buffered disk reads:86 MB in 3.01 seconds = 28.67 MB/sec
How to save the output from top command
Answer:
Use the following tricks to save the output of top command into a file.
# top -n1 > output.txt
Reduce the chance of using swap if you have enough memory
Answer:
If you have enough memory but the Linux is still using swap at sometimes, you can adjust the swappiness parameter
1. See the current setting
# cat /proc/sys/vm/swappiness
60
The range is from 0 to 100 (lower value means you system will try to avoid swap as much as possible)
2. To set a lower value at runtime
# echo "30" > /proc/sys/vm/swappiness
3. To set it permanently
# /sbin/sysctl -w vm.swappiness=30
Reboot after the changes.
Dec 312009
Turn off ETag in Apache
Answer:
ETag should not be used in Apache unless you know what they are really for.
Edit the Apache configuration: vi httpd.conf
Add:
FileETag None
Then restart Apache.
