The RIA (research in action) fair is on Tuesday, and several lab members are demoing research for it. The hard drive replacement was a success for zeus, and it appears my roll-out of flash, thunderbird and firefox updates has been successful as well. Only a few machines haven’t been restarted. Here are some of the tasks for this week:
I was away at the beginning of the week, but I’m back now. We’ve had some interesting issues come up with some of the Western Digital 250GB drives we use for linux home directory storage, so I’ll be concentrating on that along with some other technical admin tasks this week.
I found a useful way to review the windows folder on clients via file sharing. Basically, an ADMIN$ folder is accessible for every client machine the active directory admin has access to. It will allow you to view and alter files in the c:\windows directory.
After workng out some of the issues with the group policy updates for Firefox, I’m hoping to roll out the flash update along with the windows updates that are scheduled for this week.
Occasionally, I’ve noticed that some computers in the active directory domain we have will no longer update their group policy. When the computer is restarted, the error message given is :
Windows cannot find the machine account, No authority could be contacted for authentication. .
The solution to this issue, or at least a work-around, is to power off the affected computer and disconnect the power until the motherboard loses power. After it is powered up, it resumes normal function in the active directory domain and the group policy updates.
It’s been a while since we’ve updated, so there is a recap for the task items that were previously in this list in the entry for March 2nd, 2009.
Next week: Patch Tuesday, so there will be some scheduled downtime for windows computers.
It’s been a while since I’ve posted, so we’ve managed to clear a few of things on the task list. I’m going to talk a little bit about them here. The cluster update was a success, but I found a side effect of having the path include a reference to itself (to allow cluster specific binaries to be available). When building adding packages or changing the default partitioning scheme for the cluster nodes, the build process would fail if the root environment was accessed from a user who had this path setting and used su. It would build, but the install process would fail because key files aren’t copied in the hierarchy. Specifically, updates.img and stage2.img would be missing.
The active directory move was accomplished by using several vmware instances to test out the various stages. There is still some work to be done with the security certificates, and then the old domain structure can be removed. The cs disk space move was accomplished without incident.
We’ve been experiencing an interesting problem on our cluster nodes which causes them to freeze up. It appears to be related to the way the linux kernel in CentOS deals with memory allocation requests. The issue is caused by the swap partition on a machine filling completely, which freezes the system. Any attempt to start a new process hangs, waiting for space to become available from the swap (which it never does). There are several ways of trying to deal with this. The first is to use oomkiller, a process that will detect when the memory limit is going to be reached and kill a process it decides can be sacrificed for the greater good. this is a good description of the memory issues and how to test for them.
The ssl certificate installation was sucessful on the mail server, so I will be rolling out certficates from the same authority for the web server and other web applications we host. We will also be trying an upgrade on the cluster operating system, as well as moving the cs home directories to a new disk array.
We had a bit of excitement yesterday with one of the partitions on our main linux file server. It appears that the drive is beginning to fail. I’ll be testing it this week along with my other work.