System locks up when disk I/O is saturated

Solution 1:

I have had the same issue on my laptop, which has a fairly slow disk system as compared to the remainder of the computer.

I was able to make this much better, by changing the scheduling algorithm used for disk transfers. By default Ubuntu uses Deadline, but I find my system responds more quickly when I use cfq.

To see what scheduler you are using, issue the command

cat /sys/class/block/sda/queue/scheduler    

To do a one-time change (until reboot) issue the command

echo cfq | sudo tee /sys/class/block/sda/queue/scheduler

Note that it is important that the change be made to whatever it is that you have for your external hard drive; Mine usually loads up as sdb. so I would issue the command echo cfq | sudo tee /sys/class/block/sdb/queue/scheduler

I make my change permanent for all drives attached to my computer, by adding the kernel parameter elevator=cfq in my grub file, which looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash noautogroup elevator=cfq"