find . -type d -exec chmod 755 {} \;
This will recursively search your directory tree (starting at dir 'dot') and chmod 755 all directories only.
Similarly, the following will chmod all files only (and ignore the directories):
find . -type f -exec chmod 644 {} \;
grep -i -r somestring ./
-i means ignore case
-r means recursive
Simple stuff, but useful nonetheless.
I use the MD (multiple device) logical volume manager to mirror the boot devices on the Linux servers I support. When I first started using MD, the mdadm utility was not available to manage and monitor MD devices. Since disk failures are relatively common in large shops, I used the shell script from my SysAdmin article Monitoring and Managing Linux Software RAID to send E-mail when a device entered the failed state. While reading through the mdadm(8) manual page, I came across the "–monitor" and "–mail" options. These options can be used to monitor the operational state of the MD devices in a server, and generate E-mail notifications if a problem is detected. E-mail notification support can be enabled by running mdadm with the "–monitor" option to monitor devices, the "–daemonise" option to create a daemon process, and the "–mail" option to generate E-mail:
$ /sbin/mdadm --monitor --scan --daemonise --mail=root@localhost
Once mdadm is daemonized, an E-mail similar to the following will be sent each time a failure is detected:
From: mdadm monitoring
To: root@localhost.localdomain
Subject: Fail event on /dev/md1:biscuit
This is an automatically generated mail message from mdadm
running on biscuit
A Fail event had been detected on md device /dev/md1.
Faithfully yours, etc.
impostazioni per il settaggio di S.M.A.R.T. su debian lenny --> very cool
Install smartmontools from the repository.
thinkpad:~# aptitude install smartmontools
Enable SMART monitoring on the SATA drive.
thinkpad:~# smartctl -s on -d ata /dev/sda
Check the health of the drive.
thinkpad:~# smartctl -d ata -H /dev/sda
smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
Run a short self test on the drive and check the test log.
thinkpad:~# smartctl -t short /dev/sda
thinkpad:~# smartctl -l selftest /dev/sda
smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
=== START OF READ SMART DATA SECTION ===
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 4156 -
In order to configure smartd to monitor the hard disk, enable it in /etc/default/smartmontools.
# uncomment to start smartd on system startup
start_smartd=yes
Set the schedule and monitoring options by editing /etc/smartd.conf.
Comment out all the DEVICESCAN lines and add a line for the main hard drive.
# First (primary) ATA/IDE hard disk. Monitor all attributes, enable
# automatic online data collection, automatic Attribute autosave, and
# start a short self-test every day between 2-3am, and a long self test
# Saturdays between 3-4am. Send mail on SMART failures
/dev/sda -a -o on -S on -s (S/../.././02|L/../../6/03) -m naveen@localhost
Start the smart daemon.
thinkpad:~# /etc/init.d/smartmontools restart
* Restarting S.M.A.R.T. daemon smartd [ OK ]
