Category: linux

mdadm woes

After migrating a software RAID 5 to Ubuntu LTS 12.04, the system wouldn't come up again after rebooting. I believe Chris Siebenmann to splendidly have analysed [1] the problem: a race condition with udev losing the race. His solution is to: Change /usr/share/initramfs-tools/scripts/mdadm-functionsas follows: degraded_arrays() { + udevadm settle mdadm --misc --scan --detail --test >/dev/null … Continue reading mdadm woes

Reducing HP 4720s power consumption under Ubuntu Linux 11.10

Mainly annoyed by the loud fan I looked into ways of reducing power consumption of the HP Probook 4720s and came up with this script:#!/bin/sh -e# Increase filesystem write cache timeoutecho 1500 > /proc/sys/vm/dirty_writeback_centisecs  # Enable power management on all PCI devicesfind /sys/devices/pci* -path "*power/control" -exec bash -c "echo auto > '{}'" \;# Enable power … Continue reading Reducing HP 4720s power consumption under Ubuntu Linux 11.10