Dell 1950 EDAC issues

There are a few articles online about EDAC with CentOS 5.8 and higher, but none address the exact issue I was having. Hopefully this will help someone else out in the future.

I have a second Gen Dell 1950 in my studio I use for testing and general services for my office. I’m evaluating oVirt right now and ran into a particular issue. A Kernel module called EDAC is suppose to assist to detecting bad memory on systems. Nice feature, unfortunately, it seems that at least with CentOS 6 and older the Kernel module picks up the baseboard controller incorrectly as bad memory and my system hangs.
Easy fix, after installing CentOS, boot into recovery mode and add the following to this file:

/etc/modprobe.d/blacklist.conf

blacklist i5000_edac
blacklist edac_core
blacklist i3200_edac
blacklist radeaon

For me, this allowed CentOS 6.4 x86_64 to boot correctly.

Hope this helps someone.

Resetting Windows Server 2003 and 2008 local account passwords

Recently I had a need to reset a few administrator accounts for Server 2003 and 2008. So, here’s the skinny on how to do that:

Server 2003
So officially, Microsoft says if you forget the Administrator password for your machine and you can’t login (ie it’s not a member of a domain, the domain is unavailable) your only recourse is to re-install. Hog wash! So for 2003, you’ll need a tool to reset the SAM (Security Accounts Manager) password for the account you want to access. A non-trojan horse laden version of ERD commander is harder to come by these days. Fortunately someone has come to the rescue with a tiny utility called NTRestTool (http://pogostick.net/~pnh/ntpasswd/). 100% command line, and not very pretty, but it does the trick.

Extending an existing LVM on a virtual machine

Quick and dirty steps, this  work on all hypervisor.

1a. Add more space to the existing disk. On VMware, if the drive is thin provisioned, grow it to the new additional space.
1b. If the drive is thick, or you don’t know how to grow the disk. Add an additional disk drive.
2a. I like to move to runlevel one where nothing should be running. Use lsblk to find where the disk is mounted, dismount the directory(ies) and run fdisk against the physical disk drive (fdisk /dev/sdb for instance)
2b. If I had to add a drive we’ll need to scan for the drive, use:
/usr/bin/rescan-scsi-bus.sh or echo “- – -” > /sys/class/scsi_host/hostX/scan
Once you have that, you’ll be able to view the disk with fdisk. Use lsblk to ID the new device and use fdisk /dev/sdX to create a new partition on it.
3a. I know this sounds crazy, but delete the partition on the disk containing the mount point you want to extend. Now recreate the partition using the default values to use up all the new space. Set the partition type to 8e for LVM. Write the changes.
3b. With our new drive we need to give it a partition, select creating a new partition in fdisk. Set the format type to LVM with 8e. Write the changes
4a. Use pvextend to grow the disk. Use pvextend /dev/sdX# to grow the partition
4b. Add this new disk to the volume group with vgextend vgname /dev/sdX#
5. Finally, grow the logical volume with lvextend -r -l +100%FREE /dev/mapper/vgname

In the final command, -r will execute resize2fs for you automatically. Don’t forget the plus sign in front of the 100% otherwise it will not grow the partition even if the command executes successfully.