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Posts in Linux
Viewing the differences between two directories on Linux servers
This past week I needed to compare the contents of two directories to see if there were any differences. There are a TON of ways to do this, though my preferred way is to use diff with the "-r" (when comparing directories do so recursively) option to compare two folders: Simple, easy and it gives you the output you're most likely after. Anyone found a simpler solution that this? :)
$ read more →Conditionally restarting Linux services
Periodically I need to start a service, but only if it's not currently running. Other times I need to restart services on a machine, but only if they are currently running. Services may have been started on the system at boot, manually by an admin, or through a systems wide management infrastructure. They may also have been disabled on a server for one reason or another…
$ read more →System management tools
When I was studying for my RHCE exam, I came across a number of references to Redhat's satellite server and its opensource spacewalk counterpart. To dig into these products a bit more, I recently attended Redhat's deployment and systems management class. I've been using satellite server for the past two years, and it's actually a really useful tool for managing configuration data and systems updates in data centers that solely run Redhat Enterprise Linux. Satellite server provides a number of handy features: Patch management (reporting and applying updates to servers) - Configuration management (versioning and pushing configuration data to servers) Monitoring (basic system-level monitoring) - Provisioning (provides a nice GUI that front-ends kickstart / cobbler) The commercial version of satellite server will set you back some serious cheddar, but luckily for us satellite server is based off the spacewalk opensource implementation…
$ read more →Retrieving a bunch of files with wget
I periodically need to retrieve new CentOS and Fedora releases. Sometimes I need to snag CDs (I still support machines without DVD drives), and in other cases I need DVDs. Typically when I'm playing around with new releases I grab both, and use the wget to retrieve them all at once. If you pass wget a FTP URL that contains a *, it will retrieve all of the files in the directory you are retrieving files from…
$ read more →Locating your Dell service tag without openmanage
Dell provides the openmanage suite of tools to monitor and report on the hardware in their servers. I've managed a few hosts in the past where openmanage wasn't installed, and I needed to locate the service tag so I could get the hardware in the server serviced. Luckily for me the dmidecode utility was installed, which will print the SMBIOS data that was burned in by Dell at the factory: The "Serial Number:" value contains the service tag number of the server, and it should match up with the value in the BIOS as well as the one on the tag that is on the back of your server. So if you manage a Dell server that doesn't have openmanage installed (and more importantly the omreport utility), dmidecode and lspci should make you very very happy…
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