HP dc5800 Linux Boot Fix
If your attempting to install CentOS 5.2 on a HP dc5800 and it’s hanging, you need to alter the boot line during install.
linux pci=nommconf
This will allow the CentOS Installation to continue.
Configure default paper size in LaTeX
If you use LaTeX and produce PDF’s in the U.S. you may find that your documents are being produced on A4 paper instead of letter paper even though you have defined letterpaper in your document class. If you create just DVI output it works correctly, but as soon as you convert to PDF, or use pdftex, the document is still on A4. What’s going on?
Believe it or not, it doesn’t really matter which PDF generation mechanism you are using, all work in the same manner and therefore exhibit the same behavior. Whether it’s pdftex, dvipdfm, or ps2pdf, all don’t/can’t use the document class paper size definition. So if that’s all that’s been set, that’s not enough.
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VirtualBox P2V Success
I’ve been using VirtualBox prior to 1.4, and P2V’ing a Windows host into VirtualBox has been close to impossible. With some hints from Katsumi Inoue and a comment from Robert, I’ve been successfully able to P2V my primary Windows host at work. The following is a quick rundown on how I did it with VirtualBox 2.1.2 and VMware Converter.
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Removing EMC SAN Disk from AIX using powerpath
To unmap EMC disk that is connected and using powerpath:
- Remove the device from powerpath:
powermt remove dev=[hdiskpowerX]
- Remove powerpath hdiskpower devices from system:
rmdev -dl hdiskpowerXX
-
Remove standard SAN disk devices:
rmdev -dl hdiskX
- Confirm
lsdev -Cc disk
and again with inq
inq
Lack of .Xauthority
Have you ever had an issue with running X clients on a firewall protected host where you can’t login directly as the user? I happens more often than you might think. Here’s an example:
You are user “A” on “hostA”, and hostA is your client machine. Host “hostB” is the host in which you need to run the X application on as user “B”. Furthermore, hostB only allows SSH connections. In addition to the SSH restriction, you need to run an X application as someone other than yourself and you don’t have the password but you can use sudo to become that user. What can you do?
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Setting up stronger password policy rules in Linux – Part II
In a previous post we discussed how to setup stronger password policy rules in Linux and found out that any changes we make are not reflected back to existing accounts. So how do we make these changes retroactively apply to existing accounts?
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Learning to play
Totally off topic, but I’ve always wanted to learn to play hockey. There’s just something about this sport that has always captivated me. The combination of skill on the ice with the very physical action that occurs during the game just makes for a great sport. I love to watch it and I’d really like to be able to compete. I’m a very competitive person, so it means I go full throttle.
Only one slight problem — I can’t skate particularly well. Which in reality is a nice euphemism for, “I completely suck at skating.” So with a new pair of hockey skates and a reckless abandon for my own personal safety, I take to the ice in an effort to improve my skating ability. I’ve been on the ice every day and I’ve made real progress. So much so, that I enrolled in an adult developmental hockey class.
So for the next six Sundays, I’ll be on the ice seeing how far I can push myself in a sport that has no longer remained elusive to me.
Setting up stronger password policy rules in Linux
Increased password security is no longer an optional item in setting up a secure system. Many external organizations (such as PCI) are now mandating security policies that can have a direct effect on your systems. By default, the account and password restrictions enabled on a Linux box are minimal at best. To better secure your hosts and meet those requirements from external vendors and organizations, here’s a small how-to on setting up stronger password and account policies in Linux. This is targeted at RHEL so other distributions may or may not be 100% compatible.
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Setup SAN disk for use in a Linux Veritas cluster
For this particular exercise we’re going to go through the entire process of provisioning disk for use in a VCS cluster. We will use EMC Symmetrix disk zoned and masked to a RHEL 4u6 host as the foundation.
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Find WWN’s on Linux
To find port and node WWN’s while the system is running:
- 2.4.x Kernels
> cat /proc/scsi/[hba_type]/(n)
wherehba_typeis the driver (e.g. lpfc for Emulex) and(n)is the HBA number. - 2.6.x Kernels:
> cat /sys/class/scsi_host/host(n)/[port_name|node_name]
Hosts with multiple HBAs are enumerated via host(n) (e.ghost0).
You can use lsmod to determine which driver is in use.