Archive
Posts from 2011
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…
$ read more →Securing your Linux vsftp installations by locking down your server and chroot()'ing users
As much as we all hate FTP and the insecurities of the protocol, I've given up on the fact that it's going to be retired anytime soon. A lot of old legacy systems (mainframes, AS400s, etc.) don't support SSH, but they so support the infamous FTP protocol. These two factors force a lot of companies to continue to use it, so we need to take every measure we can to protect the FTP servers that receive files from these systems. I've been using vsftpd for quite some time, and it has one of the best security track records of the various FTP server implementations…
$ read more →Printing the current sector size of a device in Linux
In the past year, a number of disk drives started shipping with 4K sector sizes. To see if your disk drive is using 512-byte or 4K sectors, you can use the blktool utility to print the sector size of a device: You can also look at the hw_sector_size value for a given device in /sys, but who wants to do that when a sweet little utility like blktool exists. There are various other ways to do this, and you comments and suggestions are welcome. :)
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