Technology Errors

CentOS Linux Parted Error: Unable to open /dev/sdc – unrecognised disk label

While rebuilding a large RAID 5 logical drive I had to use parted instead of fdisk. It has been awhile since I had to build a logical drive that was over 2TB so it had been quite awhile since I have used parted which will perform the same basic functions as fdisk and more. Anyhow when first attempting to use parted to create a partition table on the logical volume sitting on top of an Adaptec RAID card with multiple 2TB drives configured as RAID 5 on CentOS Linux I ran into an error. The resolution is easy but needed to note for myself as much as anything else.

Information Security

bulk_extractor : Backtrack 5: Forensics: Forensics Analysis Tools: bulk-extractor

The bulk_extractor tool is one of the tools on Backtrack that a single article is not going to do it a lot of justice but hopefully after reading the below you will be able to see the benefits and understand basic usage of this amazing tool. The bulk_extractor actually reminds me of various tools such as Power Grep for Windows that can be used in penetration tests to locate private data worth being called out in a deliverable. By no means will the below be a complete howto for the bulk_extractor but again it will attempt to shed some light on its purpose and some easy ways it can be used.

Technology Insights

Create A New Logical Volume In A Logical Volume Group With Space On A Linux Server

As noted in a previous article I have been working on a couple new Linux servers with a minimal install of CentOS on them. The /var, /usr, and / directories each were configured with 2GB of space within a logical volume group that has 1TB of space available. I first expanded the /var and /usr directory from 2GB to 20GB and then expanded the root, or /, directory from 2GB to 30GB. Once all three of these directories were expanded I next needed to create a new logical volume group and a partition to hold PostgreSQL data. Use the information below to create a new logical volume, format it with the ext3 file system, mount it, and configure it to be mounted automatically upon the next boot of the server.

Technology Insights

Remove A Logical Volume From A Logical Volume Group On Linux

While testing various settings and other changes with logical volume groups I had created a test logical volume group that I no longer needed so I needed to remove it. When using the below information be aware that any data contained within the logical volume group will be gone after the logical volume is removed. The information below explains how to first list the current logical volumes with lvscan and then how to remove a specific logical volume with the lvremove command.

Technology Insights

Expand A Partition That Is Part Of A Logical Volume Group While Server Is Running

I recently had a couple new CentOS Linux servers brought online at a colo that a company I work for uses. I had the colo do a very simple install of CentOS so I could handle the details without having to remove a bunch of packages we didn’t need. The servers have two one terabyte drives installed in a RAID 1 configuration which provides us with one terabyte of usable disk space and upon initial configuration had a logical volume group created with three logical volumes. Each of the logical volumes, which included /var, /usr, and /, only had two gigabytes of space so I needed to first expand those logical volumes and later will be creating a large logical volume used for database data. Below I describe expanding already existing logical volumes when there is room to grow in the logical volume group.