Archive for the ‘System Administration’ Category

StackOverflow for Databases – Site Proposal at Stackexchange

Wednesday, October 6th, 2010

http://bit.ly/outerjoin

I’m supporting a proposal to create a new Q&A website for database professionals, system administrators and software developers who wish to improve their database skills and learn from others in the community..

It’s built on the same software as stackoverflow.com, a hugely popular site where over seven million programmers help each other with difficult programming problems. On Stack Overflow the audience votes for the best answer, so the answer you want is usually right at the top, not on page five.

I’m hoping that a site for database professionals, system administrators and software developers who wish to improve their database skills and learn from others in the community. would have the same kind of network effect and turn into an amazing resource.

The proposal process is going on here:

http://bit.ly/outerjoin (or http://area51.stackexchange.com/proposals/4260/databases )

If you’re interested in participating, go to that URL and click on the green “Commit” button.

Thanks!

Posted in database, System Administration | 1 Comment »

Belkin’s false advertising: OmniView PRO3 KVM switches are not compatable with the KVM over IP addon

Wednesday, September 22nd, 2010

A word to other System Administrators out there.

I have a dozen  Belkin OmniView PRO3 KVM Switches, and I was hoping to convert these to be KVM over IP devices, so that we could access more devices remotely from home, and possibly get rid of our Serial Console devices.

Belkin ships their PRO3 switches with a flyer which says I can buy an add on to convert the Switches to a KVM over IP device, using the OmniView IP* 5101K – KVM/IP Device (Part # F1DP101M). In fact, Belkin’s knowledgebase says that these devices should work fine together. But apparently this is a lie.

According to Belkin support, these products have several compatability issues. I didn’t press on those specific issues (it’s difficult to have a conversation over IM with someone who has poor English skills). Here is an excerpt from my chat:

ME : Hello, I have an OmniView PRO3. Are there any add-on products to convert this switch into a KVM over IP switch? The KVM switch came with a flyer that says I should ask for the F1DP101M, but Belkin support told that this doesn’t work with the OmniView PRO3.
ME : Hello?
BelkinSE: We are extremely sorry to inform you that F1DA116Q when used with F1DP101M has some compatibility issues and we do not recommend it.
BelkinSE: But F1DP101M works well with SMB KVMs
ME : Ok, are there any IP over KVM solutions for the PRO3 KVM?
BelkinSE: Unfortunately no.
ME : Too bad.
ME : Your website says that the F1DP101M will work with the PRO3 switches. See  http://www.belkin.com/support/article/?lid=en&pid=F1DA108Z&aid=14348&scid=0
BelkinSE: That’s correct but when tested under lab there were some complexity involved in configuration and we do not recommend using F1DP101M with PRO3 KVMs
ME : Hm. Ok. I guess I won’t buy one.
ME : You need to fix the website, because it is misleading.
BelkinSE: Well we are extremely sorry for that information on the website
BelkinSE: But we will definitely take that in consideration and fix that issue on the website.
ME : Thank you for the information. Good bye.

Posted in System Administration | No Comments »

California threatens to close ACCRC, an innovative computer recycler

Tuesday, October 2nd, 2007

The Alameda County Computer Resource Center is an innovative computer recycler in Berkeley, CA. They are an environmentalists dream– all waste is reused when possible, the rest is recycled. No waste is shipped to questionable trash dumps overseas. Locally, the ACCRC provides computers to local schools and nonprofits.

During the Makers Faire in San Mateo, California, the ACCRC brought in tons of computer and electronic parts which were salvaged and reused for various projects.

Sadly, the State of California is threatening to shut down the ACCRC, mostly for failing to maintain an inventory of all of their computer equipment, and for keeping interesting/historical equipment onsite (a Computer Museum), instead of destroying the equipment.

I’ve been using ACCRC (and their predecessors) for years, and I’ve volunteered for several Linux installfest events using their hardware. I sincerely hope that State is able to work with the ACCRC and reach a compromise.

Posted in Berkeley, Geek, System Administration, Uncategorized | 1 Comment »

Merging conflicts in Subversion is as easy as falling off a bike

Thursday, July 7th, 2005

I’m studying the Subversion Version Control System and ran across this humorous quote in Chapter 3:

Merging conflicts by hand can be quite intimidating the first time you attempt it, but with a little practice, it can become as easy as falling off a bike.

You would think they actually meant “as easy as riding a bike”, but no … I think they really did mean falling. Merging conflicts in files is tradionally the bane of all version control systems. I’ve seen developers throw their hands up in the air, give up, and run to the bar for a good beer when resolving conflicts in Clearcase & CVS.

We’ll see if SVN is any better at handling conflicts.

Posted in Geek, Quotes, System Administration | No Comments »

How to secure a computer

Wednesday, June 29th, 2005

The only truly secure computer is one which is switched off and disconnected from the network.

… and smashed with a sledgehammer, to ensure that the computer is never turned on again.

… and set on fire, to the temperature of 600F, which should be sufficient to destroy the magnetic bits in the hard drive.

… and then nuke it from orbit, it’s the only way to be sure.

Posted in Geek, Quotes, System Administration | No Comments »

SuSE 9.1 vs. VMware (vmware-config-tools.pl vs. kstrdup )

Wednesday, January 26th, 2005

I’m testing out SuSE 9.1 on VMware 4.5.2 on top of Windows XP.

VMware comes with the ‘vmware-tools’ package, which enhances performance and usability when running SuSE or any flavor of Linux under VMware.

Unfortunately, vmware-tools fails to build with the following error:

# ./vmware-config-tools.pl
(… snip …)

make[1]: Entering directory `/usr/src/linux-2.6.1-111′
/tmp/vmware-config/vmhgfs-only/cpName.o
/tmp/vmware-config/vmhgfs-only/cpNameLinux.o
/tmp/vmware-config/vmhgfs-only/dev.o
/tmp/vmware-config/vmhgfs-only/dev.c:20:
/tmp/vmware-config/vmhgfs-only/main.h:184: error: conflicting types for ‘kstrdup’
include/linux/slab.h:121: error: previous declaration of `kstrdup’
make[2]: *** [/tmp/vmware-config/vmhgfs-only/dev.o] Error 1
make[1]: *** [_module_/tmp/vmware-config4/vmhgfs-only] Error 2
make[1]: Leaving directory `/usr/src/linux-2.6.1-111′
make: *** [vmhgfs.ko] Error 2
make: Leaving directory `/tmp/vmware-config/vmhgfs-only’
Unable to build the vmhgfs module.

EWW! GROSS!

This is because the function ‘kstrdup’ in the vmware-tools source (in the vmhgfs module) is conflicting with the function ‘kstrdup’ in the Linux kernel source, in mm/slab.c , drivers/md/dm-ioctl.c , and a few other places.

To work around this error, you need to modify the vmware-tools source a little bit.

- Find the file vmhgfs.tar and untar it:

cd modules/source
cp vmhgfs.tar vmhgfs.tar.old
tar xvf vmhgfs.tar
cd vmhgfs-only

- in main.c main.h and driver.c , replace the string ‘kstrdup’ with something unique, like ‘vmkstrdup’.

Then tar it back up, remove your old temprary files and re-run the tool again:

cd ..
tar cf vmhgfs.tar vmhgfs-only
rm -rf vmhgfs-only

Rerun vmware-config-tools.pl and it should work!

Posted in System Administration | No Comments »

D-Link DI-514 vs. Windows 2000 – Blue Screen of Death

Thursday, June 3rd, 2004

I finally got a wireless network. I was waiting for the equipment to come down in price. TigerDirect had some refurbished 802.11b D-Link components for sale. $20 for the router: A D-Link DI-514, $15 for each of the D-Link DWL-520 network cards. So I bought them (still waiting for the refund from D-Link).

I installed the router, installed the DWL-520′s (Which came with the wrong Driver CD!), configured everything and off I go!

For the most part the network works great, but sometimes Windows 2000 will crash into a Blue Screen of Death with this message:

DRIVER_IRQL_NOT_LESS_OR_EQUAL

*** STOP: 0X000000D1 (0X0191A400,0X00000002,0X00000001,0XF828B908)

*** NETR33X.SYS – Address F828B908 base at F827B000, Datestamp 3ecdaf93

Annoying as heck. Now, note that NETR33X is the driver for many D-Link cards, including the D-Link 520.

These crashes only happen my network has alot of traffic. I’ve been trying to use Bittorrent to download the latest version of Red Hat Fedora Linux, and the crash usually happens when my download speed goes over 150 Kb/s.

Well, while troubleshooting this and downloading Fedora at 150 Kb/s, I received a phone call. We have one of the cheap common Uniden cordless phones. As many of you know, many cordless phones transmit at 2400 Mhz. The 802.11b and 802.11g wireless networks *also* transmit at 2400 Mhz.

So I pick up the phone, listen to the caller, and there is alot of noise. I know that the Uniden and my wireless network transmit on the same frequency range, so I try to change wireless channels on the Uniden phone. I hit the “Channel” button, and at the exact same time, boom — Blue Screen of Death.

It looks like the D-Link cards have trouble dealing with wireless signals from other devices.

After changing channels on the Uniden phone, there have been no crashes at all. My Bittorrent has even reached 170 Kb/s ! Yes.

Posted in Geek, System Administration, Uncategorized | 2 Comments »