Replace failed hard drive

1. Determine SCSI ID

   lsscsi

2. Release drive from SCSI controller

   scsiadd -r 0 0 0 0

3. Add new drive to SCSI controller

   scsiadd -a 0 0 0 0

4. Copy partition table from sda to sdb

   sfdisk -d /dev/sda | sfdisk /dev/sdb

Print every line except the first line

sed -n 2~1p

Strip HTML tags

sed -e 's#<[^>]*>##g'

RHEL4

List Available Updates

up2date --dry-run | sed -n '/solving RPM inter-dependencies/,/The following Packages were marked to be skipped by your configuration/p' | sed -n '/^$/,/^$/p' | sed -n 4~1p | sed '/^$/d' | awk '{print $1 " " $2 "-" $3 "-" $4}'

RHEL5

List Available Updates

yum -d 0 check-update | awk '{print $1 " " $2}'

Read qmail logs

zcat  | tai64nlocal | less

Relay to a smart-host

echo ":smtp.example.com" > /var/qmail/control/smtproutes

Queue Status

/var/qmail/bin/qmail-qstat

or

/var/qmail/bin/qmail-qread

Flush Queue

killall -ALRM qmail-send

Puppetmaster

Create CA Certificates

puppetmasterd --certname puppet.example.com

Set default "From:" address for email (UNIX)

sendmail_path = "sendmail -t -i -r user@example.com -f user@example.com -F user@example.com"

Or for inline apache configuration:

php_value sendmail_path "sendmail -t -i -r user@example.com -f user@example.com -F user@example.com"

Connect to database

sqlplus '/as sysdba'

Connect to remote Oracle server

sqlplus "sys/password@host/sid as sysdba"

Find versions

SQL> select * from v$version;

Prepare for patching

sqlplus '/as sysdba' -- Connect to DB
shutdown abort -- Kick all users off
startup restrict -- Restore any dangling transaction from above shutdown
shutdown immediate -- Clean shutdown
exit -- Disconnect from DB
emctl stop dbconsole -- Stop web console

Purge Binary Logs

Purging binary logs can free up a lot of space in a crunch. These logs are primarily used for replication, and don't necessarily need to be kept for very long.

Windows

Munin Node for Windows can be downloaded from http://sourceforge.net/projects/munin-nodewin32/

There are a few items that do not work out of the box:

Cycle Error Logs

sp_cycle_errorlog

Force a database out of "Restoring..." Mode

RESTORE DATABASE  WITH RECOVERY

Find duplicated column data

select 
convert(varchar(20), a.[samaccountname]) as [user], 
convert(varchar(20), a.[domainname]) as [domain],
from BTS_ActiveDirectoryReporting.dbo.Users as a
where a.[samaccountname] in 
(select z.[samaccountname]
from BTS_ActiveDirectoryReporting.dbo.Users as z
group by z.[samaccountname]
having count(*) > 1)

Search for a column in a specific table

select COLUMN_NAME