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Sep. 9th, 2009


Just so we're clear:

Terrorists killed 3000 Americans. In response, America was willing to pay any costs in order to pursue and punish terrorists and their supporters.

Treatable disease kills thousands of Americans every year. Health insurance reforms which would prevent future deaths is too expensive to enact.

Do I have that right?

Aug. 14th, 2009

(no subject)

If I ever start a development studio, I think I'm going to name it "Seeping Head Wound" after today's accident.

PS: ... or maybe a punk band. My judgement may be impaired.

Jul. 6th, 2009

Stolen bicycle

Last weekend my building manager left the garage open all weekend due to concerns about the gate, which was an open invitation for the garage to be looked through. Someone stole Krystina's front tire during that weekend. Last night it looks like they came back. It probably wasn't too difficult to get in, and several bikes were stolen, including mine.

I'm going to be keeping an eye on craigslist, as well as calling used cycle shops around Seattle and, if I can find the serial in my paperwork, filing a report with the police department. Anyone have any other ideas where stolen bicycles tend to end up?

Jun. 22nd, 2009

Dell customer support

Earlier this year I sold my IBM X40 (of which I was very fond) and upgraded to a Dell Latitude E6400. It's a very nice laptop, though significantly heavier than the X40 was. I wanted something with hardware virtualization support, a lot of RAM (this one goes to 8GiB!), and Gig-E.

I've been quite happy with it, but recently I've noticed that the battery isn't holding a charge properly. After about a minute off of AC, the charge indicator drops to 80%. I contacted Dell support about the issue late Wednesday, and they suggested that I update the BIOS. I didn't get back to them on Thursday, and left town early Friday. They called to follow up on Friday, Sunday, and Monday just as I was getting ready to call them back. After I updated them on my results, they're shipping me a new battery.

I'm really happy with their follow up and the ease of getting a new part to resolve my issue.

Apr. 30th, 2009

Netgear GS724TP

Recently, looking for some less expensive managed switches to use as an alternative to HP's excellent Procurve line at more cost-concious sites, we purchased a couple of Netgear GS724TP units. I continue to hold some reservations regarding Netgear products, but I've been told that they have improved considerably in the last several years. At one of these sites, I wanted to consolidate some smaller switches in order to reduce electrical use and heat in a confined space. I turned to the GS724TP's management interface to set up a pair of VLANs and was left totally befuddled. The management interface would allow me to make ports a "member" of a new VLAN, but they remained members of the original VLAN. I expected them to automatically be removed from the membership of the original VLAN, as is the case in other managed switches. The interface would not let me manually remove them from the default VLAN, either, which is nonsense. As long as untagged packets are output to every port, using untagged VLANs changes nothing at all. The documentation was useless, so I called Netgear.

The answer I got from their technical support line was pretty ridiculous.

The switch that we're using separates the configuration of untagged packets into separate input and output sections. The interface marked "VLAN Membership" allows users to mark each port as a tagged or untagged member of each VLAN, or not a member of the VLAN. These marks indicate how packets received on a given VLAN will be output to each port. The interface maked "Port PVID configuration" allows users to mark each port with a "PVID". This setting controls what VLAN will receive packets which are sent to this port without a VLAN tag. VLAN 1 is the management VLAN and cannot be modifed. All ports will always be output ports for VLAN 1 traffic.

The documentation does not explain this behavior, and in fact contradicts it by showing multiple screenshots of the interface where a subset of ports are untagged "members" of VLAN 1.

The entire paradigm of setting untagged VLAN memberships in input and output separately is ridiculous. There is no situation where you would ever be able to use asymmetrical untagged port memberships. If a device sends untagged packets, it must receive them untagged as well. If a port is configured to output untagged packets for a VLAN, this logically implies the reverse, which makes the "PVID" interface completely unnecessary.

Also troublesome is the fact that since all ports are always output members for VLAN 1, that VLAN is unusable where users want to segregate traffic between two VLANs. In that situation, which will virtually always be the case where VLANs are used, users must create VLANs for both (or all) of their segregated networks, and not use VLAN 1 at all. However, only members of VLAN 1 can reach the switch's management interface. Users can solve this in one of two ways: Either they can have a host which is connected to two ports (one of which uses the default configuration), or they must configure one host's port to be a tagged member of the desired VLAN -- leaving the PVID configured as "1" -- and configure the desired address on a tagged interface on the host, with an additional address for management on an untagged interface on the host.

Finally, as far as I can tell, any port is capable of accepting tagged packets from any VLAN id, which means that any host can inject packets to any VLAN, which may be viewed as a substantial security flaw.

Apr. 14th, 2009

(no subject)

Can you even say "tea-bagging" on TV?

Apr. 4th, 2009


I finally got around to reading Anandtech's very long article about the current crop of SSD drives. I feel like it was pretty educational, which is good because it took a long time to digest.

In its discussion of performance degradation as drives are used, the article explains that individual pages of NAND memory can't be rewritten. Early in a drive's life, page are remapped when they are rewritten by the OS. As the drive is used, the drive runs out of pages to remap and is forced to copy a block (typically a 512KiB collection of 4KiB pages) to cache, erase the block and then rewrite the block with the new pages. That explains pretty well why write performance degrades, since writing to a block that has data must perform a read and erase operation in addition to the write. However, that explanation also leaves open the question of how the drive prevents data loss if it loses power. Worst case, the OS issues a write and the drive copies a 512KiB block to cache and erases the block, and then loses power. Due to remapping, literally anything could be in that half a MiB. The data loss could corrupt the file that was being modified, obviously, but also any other file on the drive, or parts of the filesystem itself.

I figure there's got to be protection against data loss built-in, but I'm not able to find details regarding any individual drive or manufacturer's approach to solving that problem. Does anyone know more about this subject?

Oct. 25th, 2008

(no subject)

crankygirlie posted a link to a special comment by Keith Olbermann, and I laughed my ass off. I haven't been paying attention to Keith much lately; I keep reading that he's been making an ass of himself lately. He's certainly a lot more snarky than I remember him being.

I wish there were more coverage of the bullshit that Palin's been producing. Krystina's been reading election coverage and disgusted with the amount of time spent discussing her looks and her pageant history. I agree, but that's what an awful lot of American media is today: not liberal or elite, just trashy tabloid fare.

The Wasilla Project has some great interviews with the people of Wasilla who are unhappy with her time as mayor of the town. It's not balanced, but I don't know of any reason to believe that it's inaccurate, and what's portrayed there is shocking.

Palin entered office with virtually no debt, and left the city more than $20 million dollars in debt. The town had a population of only 6300 people when she left office.

She campaigned as a fiscal conservative, but spending clearly outpaced income for the city and the one cost she's known best for cutting was rape kits which were billed to the victims of rape. The woman spent fifty thousand dollars to remodel the mayor's office without approval. The highest paid member of the McCain/Palin campaign is the person who does her makeup. The fourth highest is the person who does her hair. Her clothing for the campaign cost one hundred fifty thousand dollars. That's not fiscally conservative.

Someone ought to ask Sarah Palin if she's soft on crime, or if she just really hates women.

And then there's the question of whether or not she has any respect for the law. That fifty thousand dollar remodel without the approval of the city council suggests the answer is "no". And the eminent domain lawsuit over the land where the city built the sports center. And using personal secret email accounts to conduct official business. And using the mayor's office to conduct a political campaign. And the lawsuit over her firing of the Public Safety Commissioner. This is the sort of thing that people should take a lot more seriously than I think they do. Officials who lack an understanding of, or respect for the law see public office as purely power. That's the threat of "big government": the authority of office will become a weapon in the hands of people who don't believe that there are restraints.

Haven't we had enough of lawless, big spending, big government leadership in the White House? What the hell happened to the Republican party that opposed all of those things?

Oct. 16th, 2008

3ware controller migration

Yesterday I had to move drives from a very unreliable 8000 series 3Ware controller to a new 9000 series controller. My preference is to use software RAID whenever feasible because I know that disk migration in the event of hardware failure will be easier. I was concerned that the process would be troublesome, and I was right.

I originally replaced the 8000 series card with the 9000 series card unaware that the firmware in the new card wasn't capable of reading the old array data, and under the advice that the new card was compatible. After the drives were moved, the new controller showed the drives as "unconverted DCB" (I believe).

It was suggested that I make a new RAID1 array of the drives, which I did. This failed to achieve the desired result. The new array had the data from the old system, but it was 1024 sectors into the "disk". I was now unable to boot the system on the new controller because the data was offset, and also unable to go back to the old controller, which would report success in setting up a new RAID1 array, but would always fall back to exporting two individual disks after exiting the configuration utility.

That's where we learned from a post to a mailing list (via Google) that we'd need a utility from 3Ware, and would have to contact their support technicians to get it. The requirement is documented in the 9000 series manual, but we hadn't seen it. The tool is not available on the vendor's site. It's also not capable of fixing the drives unless they're connected to a working 8000 series controller. If your controller is dead and you don't have a replacement: you're boned. The tool can't fix drives even if they're connected to a non-RAID disk array.

We worked with 3Ware to get the tool, but they left the office promptly at 4PM without providing us a solution. Since we don't have the luxury of office hours, I reasoned that there was a slow way to fix the problem. I copied the data from the RAID array to an external drive using the following Linux command:

# dd if=/dev/sdb of=/dev/sda bs=$((1024 * 512)) skip=1

"sdb" was the RAID1 array on the 9000 controller, and "sda" was the external drive. It wasn't necessary for the restoration, but it was a helpful validation that the solution that I had in mind would work, and a backup in case of failure. After copying the data, I was able to read the partition table and mount filesystems from "sda".

I felt comfortable with that solution, so I proceeded to move the data blocks on the RAID array:

# dd if=/dev/sdb bs=$((1024 * 512)) skip=1 | dd of=/dev/sdb

After rebooting, the drive appeared to be readable normally.

I'm not sure where the 9000 controller puts its metadata, nor am I sure how much data it stores. My guess is that it took a small block at the end of the disk, destroying whatever was there when the drives were connected to the 8000 series controller. The data at the end of the drive was a swap partition, so in our case we probably weren't hurt by the conversion. I don't really trust the process in general, but the risk seems low and it appears to be working properly.

This mess is exactly why I avoid hardware RAID when I can.

Oct. 10th, 2008

The Plan

The PlanCollapse )

The plan always reminds me of my time at a nameless former employer. The biggest problem that I think we had was that the organization was too deep, and communication was filtered through too many layers. Upper management had no idea what was going on in the company, because they were entirely removed from actually talking to their employees.

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