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EC2 Instance Metadata

31-Aug-10
> curl -s http://169.254.169.254/latest/meta-data/
ami-id
ami-launch-index
ami-manifest-path
block-device-mapping/
hostname
instance-action
instance-id
instance-type
kernel-id
local-hostname
local-ipv4
placement/
public-hostname
public-ipv4
public-keys/
reservation-id

Testing Puppet syntax without running puppetd

23-Aug-10

Use the --parseonly (puppet.conf manpage: “just check the syntax of the manifests”) and --ignoreimport (“enables you to parse-check a single file rather than requiring that all files exist”) flags to the puppet comand:

> puppet --parseonly --ignoreimport <filename.pp>

Reference: Puppet

Example checkinstall arguments

02-Aug-10
> sudo checkinstall -D --pkgname openldap_proxy --pkgversion=2.4.22-hrc --arch=amd64 \
  --maintainer=sysadmin@example.com --nodoc

Checking Zone Serial Numbers

06-Jul-10

Use the +nssearch flag to dig: “When this option is set, dig attempts to find the authoritative name servers for the zone containing the name being looked up and display the SOA record that each name server has for the zone.”

> dig +nssearch hurricane-ridge.com
SOA ns2.hurricane-ridge.com. domainadmin.hurricane-ridge.com. 2009081500 3600 1200 2419200 3600 from server ns6.dnsmadeeasy.com in 18 ms.
SOA ns2.hurricane-ridge.com. domainadmin.hurricane-ridge.com. 2009081500 3600 1200 2419200 3600 from server ns5.dnsmadeeasy.com in 28 ms.
SOA ns2.hurricane-ridge.com. domainadmin.hurricane-ridge.com. 2009081500 3600 1200 2419200 3600 from server ns7.dnsmadeeasy.com in 54 ms.
SOA ns2.hurricane-ridge.com. domainadmin.hurricane-ridge.com. 2009081500 3600 1200 2419200 3600 from server ns2.hurricane-ridge.com in 69 ms.

Setting SCSI Timeout Values for FreeBSD VMs on VMware/NetApp

23-Jun-10

NetApp requires setting a timeout value of 190 seconds for all VMware data stores on their filers to handle “long fabric or storage-side I/O interruptions”; this is done as follows on FreeBSD:

# sysctl kern.cam.da.default_timeout=190

This can be set permanently in /etc/sysctl.conf:

kern.cam.da.default_timeout=190

Elsewhere, I have seen a recommendation for FreeBSD on ESX that kern.cam.da.retry_count be set to 120.

Query Architecture of RPMs

15-Jun-10

To query the architecture of installed RPMs, use a custom query format:

rpm -q -a --queryformat='%{N}-%{V}-%{R}.%{arch}\n'

Mount an ISO image on Linux

15-Jun-10
# mount -o loop disk1.iso /mnt/disk

Installing Ruby Gems as a non-root user

31-May-10

Information from How to install gems when you’re not root as recorded in Google’s cache (site appears to be down from here, perhaps permanently).

Set the GEM_PATH environment variable:

export GEM_PATH=~/gems

When installing gems, use the “-i” flag:

gem install -i $GEM_PATH some_random_gem

You may wish to add ~/gems/bin to your shell’s path.

Disabling and Enabling an SGE queue

28-May-10

Disable:

# qmod -d all.q@compute-0-0.local workflow.q@compute-0-0.local

Enable:

# qmod -e all.q@compute-0-0.local workflow.q@compute-0-0.local

Configuring a Printer on Solaris

01-Mar-10

Adapted from the lpadmin man page, for an HP JetDirect printer:

> pfexec lpadmin -p lp01 -v /dev/null -m netstandard -o dest=lp01.example.com:9100 -o protocol=tcp -T PS -I postscript
> pfexec lpset -a banner=never lp01
> pfexec lpadmin -d lp01
> pfexec enable lp01
> pfexec accept lp01