Tuesday, July 22, 2008

Monitoring hard disk with smartmontools

Monitoring your hard disk health is a very important thing. You do not want to wake up one day, turn on your computer and suddenly your hard disk has crash and all your valuable data has gone with the wind. At that time crying would not get your data back. Like some people always say, prevention is better than cure. Apart from backing up your data regularly, monitoring the health of your hard disk is an essential task. It is to make sure any symptoms of bad sector or any failure can be detected earlier and steps to take care of it can be done sooner. One of the tool that can be used to do the job mentioned before is smartmontools. According to yum description, smartmontools are "Tools for monitoring SMART capable hard disks".

To install smartmontools on fedora:
# yum install smartmontools

Make sure your hard disk is smart capable
# smartctl -i /dev/sda
smartctl version 5.37 [i386-redhat-linux-gnu] Copyright (C) 2002-6 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

Model Family: Western Digital Caviar SE (Serial ATA) family
Device Model: WDC WD800JD-60LSA5
Serial Number: WD-WMAM9MA75547
Firmware Version: 10.01E03
User Capacity: 80,026,361,856 bytes
Device is: In smartctl database [for details use: -P show]
ATA Version is: 7
ATA Standard is: Exact ATA specification draft version not indicated
Local Time is: Tue Jul 22 10:05:31 2008 MYT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

Smart support is available for this hard disk and enabled

To monitor your hard disk health
# smartctl -H /dev/sda
smartctl version 5.37 [i386-redhat-linux-gnu] Copyright (C) 2002-6 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

SMART overall-health self-assessment test result: PASSED

To run test on your hard disk
# smartctl -t short /dev/sda

To see the selftest logs of smartctl
# smartctl -l selftest /dev/sda

See all options for smartctl
# smartctl -h

Manual for smartctl
# man smartctl

Wednesday, July 16, 2008

mtr, another network diagnostic tool

mtr is a network diagnostic tool that combine both traceroute and ping in one easy to use tool. As mtr starts, it investigates the network connection between the host mtr runs on and HOSTNAME. by sending packets with
purposely low TTLs. It continues to send packets with low TTL, noting the response time of the intervening routers. This allows mtr to print the response percentage and response times of the internet route to HOSTNAME. The good thing about mtr is, it will run until we ask it to quit by pressing 'q'. That means we will have a live traceroute and ping that will keep updating until we ask it to stop.

To use mtr, just type:

$ mtr www.google.com

It will display the a few statistics about ping and packets, enough for us to do some basic network diagnostics work.