Archive
Posts from 2009
Scanning Linux hosts for newly added ESX storage devices
I currently support a number of Linux hosts that run inside VMWare vSphere server. Periodically I need to add new storage devices to these hosts, which requires me to login to the vSphere client and add the device through the "edit settings" selection. The cool thing about vSphere is that the LUNs are dynamically added to the guest, and the guest will see the devices once the SCSI bus has been scanned. There are several ways to scan for storage devices, but the simplest way I've found is to use the rescan-scsi-bus.sh shell script that comes with the sg3_utils package…
$ read more →Displaying a file or device in hex
A while back I came across the hexdump utility, which allows you to dump the contents of a device or file in hexadecimal: This is a super useful utility!
$ read more →2.6.32 Linux kernel Virtualization memory De-Duplication
This is pretty sweet. In the 2.6.32 Linux kernel released yesterday, a new feature of de-duplicating memory of virtualized instances, was introduced. Modern operative systems already use memory sharing extensively, for example forked processes share initially with its parent all the memory, there are shared libraries, etc. Virtualization however can't benefit easily from memory sharing…
$ read more →Getting a daily status report from your Netbackup infrastructure
I support a couple of Netbackup environments, and like to keep tabs on what is going on with my media and master servers. There are a slew of reports available in the GUI and CLI interfaces, and these reports cover everything from Netbackup errors to tape reports to what is occurring with vault jobs. The two reports I find most useful are the jobs report and the errors report. These reports can be access through the bpdbjobs and bperror commands, and produce a nice summary of the jobs that ran and any errors that occurred…
$ read more →Configuring yum to use an HTTP or FTP proxy
I have been experimenting with squid at home, and recently configured yum to use the squid proxy server I set up. There are two ways you can get yum to use an HTTP or FTP proxy. First, you can make yum use a proxy for a single session by setting the http_proxy and ftp_proxy environment variables: If you want to make the proxy settings permanent, you can add a proxy directive to /etc/yum.conf: If your proxy requires you to authenticate, you can add the credentials to the configuration file as well.
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