Geek projects, tidbits and things I'm working on at the moment…

This one took a while. Essentially I had lost my other bootable USB flash drive and needed to make another one. I had previously used an HP utility which did the heavy lifting for me but I couldn’t find it on the interwebs nor my HD to save my life. I essentially had to use FreeDOS and SysLinux to get the job done. I’m pretty sure the wiki page I found was using an older version so I had to download FreeDOS 1.0 to find the fat32lba.bss file which was eluding me.

I will never lose this USB thumb drive…ever…bit of a nightmare really.

Useful links:

http://sourceforge.net/apps/mediawiki/freedos/index.php?title=USB

http://www.kernel.org/pub/linux/utils/boot/syslinux/ (I grabbed version 4.05!)

http://www.freedos.org/download/

Recently had a question at work about the maximum number of recipients Sendmail would allow thru our in-house server. I wasn’t sure but knew I hadn’t personally configured a hard limit. Did some quick searching and stumbled upon confMAX_RCPT_PER_MESSAGE as the answer. I haven’t set it to anything in our config but didn’t know what the default limit was in Sendmail so I did some digging. Stumbled upon the following links of value (to me at least!)

http://www.sendmail.com/sm/open_source/docs/m4/tweaking_config.html

Answer: infinite number. Sendmail doesn’t have a limit (now it does!)

Also stumbled upon Centos.org’s version 5 Deployment Guide on running the m4 macro command to build a new Sendmail.cf file.

http://www.centos.org/docs/5/html/5.1/Deployment_Guide/s3-email-mta-sendmail-changes.html

This one bit me in the behind a while back. Essentially, the AD server was restored from a snapshot but had USN numbers that were younger than another servers’ USN numbers which was trying to connect to the AD server. This put the AD server into “disabled” mode so it wasn’t being used for AD stuff. The only way I could permanently fix my USN rollback issue was by keeping the other server off and restoring it to a previous snapshot as well. Long story short, this sucked to fix.

Couple of links:

http://exchangeserverpro.com/recovering-a-single-domain-controller-from-a-usn-rollback

http://social.technet.microsoft.com/Forums/zh/winserverDS/thread/8d287ba9-fff8-4a93-998a-86e64e4b85f8

I’m getting ready to migrate our AD servers to a virtual environment and one of the things that can get messed up is the AD servers’ time. Also, I’m joining some non Windows systems to the Windows domain which might encounter some time sync issues since they aren’t currently configured to use the domain’s NTP server (easy fix I know but I’m saving that for another post!)

Short story long, your AD server typically uses its’ CMOS time versus an external NTP server which is all fine and good so long as A) it’s a real hardware server not a virtualized one and B) No other servers in your infrastructure use other NTP servers (ie. Linux server ‘A’ isn’t using tick.usno.navy.mil which will have a different time then your main AD server which is going off of it’s CMOS clock!)

So, I did some searching on the interwebs and stumbled upon a couple of useful links on how to modify your registry on your AD server so it:

A) Uses an external time source versus the CMOS time & date.

B) Has a number of servers to attempt time updates from (use spaces to delimit servers! and don’t forget to append “,0x1” at the end if you’re using a FQDN versus an IP Address!)

C)…I forget C!

Anyhow, here’s some links I wrangled up.

http://support.microsoft.com/kb/816042#method2

http://www.windowsnetworking.com/articles_tutorials/configuring-windows-time-service.html

 http://www.sole.dk/how-to-configure-your-virtual-domain-controllers-and-avoid-simple-mistakes-with-resulting-big-problems/ (this one was most helpful!)