Thursday, December 29, 2005

quick note on how to wire a straight through ethernet cable

pin1 pin2 pin3 pin4 pin5 pin6 pin7 pin8

OW - orange/white
OR - orange
GRW - green/white
BL - blue
BLW - blue/white
GR - green
BRW - brown/white
BR - brown

Here's a page with some nice tables and graphics to help understand:

Sunday, October 16, 2005

MS05-051 causes problems with ASP pages

There is a workaround by applying IWAM permissions to a specific folder. The fix given by Microsoft is to add RX permissions for IWAM on c:\winnt\registration folder - it corrects a dcom error on the server. This fix does NOT work for my application. So I have removed the patch until an appropriate fix is made.

Sunday, July 10, 2005

partimage works well for imaging ext3 filesystems!

Today I used partimage to save and restore an image of my /boot and /root ext3 filesystems on my Fedora Core 2 server. I used a bootable CD created from an iso found on This is a very nice little utility disc that has some file system tools in addition to partimage. To make it easier on yourself, I recommend you have a hard drive with a FAT partition to save and restore your filesystems to.

Here is the short list of steps to save a filesystem image:
1) make an iso cd from
2) boot with the cd
3) create a directory and mount your FAT partition read-writeable to that directory
4) run partimage and save a filesystem image to the FAT filesystem. To test out how well partimage works for you, first save an image of a filesystem that is expendable. That way, if something goes wrong, you won't mind as much.
5) run partimage and do a test verification of the restore (does not write to the destination drive)
6) if the test verification works, go for the full restore
7) after you've restored, verify that all the applications on the filesystem work

Initially hesitant, I made sure the boot filesystem restored properly first. Then I moved on to my very valuable /root partition. Since I keep my filesystems simple (/boot, /root and swap), partimagimg those three filesystems was a relatively easy procedure for me. Especially since I mounted the FAT partition for reading and writing. The restore went without a hitch and was very fast, since I used the highest level of bzip2 compression. Bzip2 saves a lot of space, but does take some time to compress. I'd say it ran about 30 minutes to compress a 4GB filesystem. This is on a P4, 3.2Ghz w/1GB RAM.

Good luck!

Saturday, February 12, 2005

"viewstate is invalid for this page and might be corrupted"

I didn't know much about .Net viewstates until yesterday when I needed to configure a .Net application living on multiple servers behind a load balancer. Suffice it to say that you need to generate an encrypted key and configure all servers to use the same key, rather than using machine.config's "AutoGenerate" setting:
machineKey validationKey="AutoGenerate,IsolateApps" decryptionKey="AutoGenerate,IsolateApps" validation="SHA1"

Here is an interesting article that tells you how to do this:

Viewstate isn't really the same as session state. Viewstate is a hidden field that stores page state between calls. The way that viewstate works is:
1. When returns an http response to a user, it compiles all the data field data into a big encrypted string.
2. The string is passed as a hidden field. When the user responds to the page, the viewstate is passed back to the server.
4. ASP.NET deserializes and decrypts the string to refill the form fields.
5. If the deserialization breaks, then you get the error "viewstate is invalid for this page and might be corrupted."

Viewstate can break if:
1. The servers aren't all using the same encryption/decryption keys.
2. The viewstate field is being truncated.
3. Other scenarios. Ahem.

Friday, February 11, 2005

This is a famous dog. Perhaps you know her.
Feel free to drop me a line or ask me a question.