Editing sysctl.conf


I’d like to change some of the settings for my RAID 5 HD, like the max sectors per IO. I know how to do this at the terminal, by entering:

echo “64” > /sys/block/sda/queue/max_sectors_kb

My question is this though. Each time I reboot this settings get reset. Can I add these commands to my sysctl.conf file so they run each time openSUSE starts up?

what about commands to set the Read Ahead Cache like

blockdev --setra 16384 /dev/sdb?

Can that also just be placed in the sysctl.conf.

If the answer is no, can anybody instruct me on how to do this?

Thank you,


  • Read “man sysctl” (especially the options for showing actual values).

  • Edit /etc/sysctl.conf with a text editor as root according to your needs.