Category Archives: Hardware

My Week

Hardware

It’s been quite the week.

Stomach Flu

Last Friday, my stomach was just starting to feel a little odd. I didn’t think much off it — a little food that didn’t go over well or stress, I thought.

Saturday I got out of bed and almost immediately felt like throwing up. Ugh. I probably caught some sort of stomach flu. I was nauseous all day and had some terrible diarrhea to boot. I spent parts of Saturday, Saturday night, Sunday, and Sunday night “supervising some emergency downloads” as the BOFH would say. By Sunday afternoon, I thought I was doing good enough to attend a practice of the Kansas Mennonite Men’s Choir. I made it through but it wasn’t quite as up to it as I thought.

Monday morning I woke up and thought the worst was behind me, so I went to work. By evening, the worst clearly was not behind me. I was extremely cold, and then got very hot a few hours later. Tuesday I left work a little early because of not feeling well.

Servers

Wednesday a colleague called me at home before I left to say that the ERP database had a major hiccup. That’s never good. The database is this creaky old dinosaur thing that has a habit of inventing novel ways to fail (favorite pastime: exceeding some arbitrary limit to the size of files that no OS has cared about for 5 years, then hanging without telling anybody why). My coworkers had been working on it since 5.

I went into the office and did what I could to help out, though they had mostly taken care of it. Then we went to reboot the server. It didn’t come back. I/O error on sda just after init started, and it hung. Puzzled, as it just used that disk to boot from. Try rebooting again.

This time, I/O error as the fibre channel controller driver loads. Again, puzzled as it just used that controller to load grub. Power cycle this time.

And now the server doesn’t see the fibre channel link at all. Eep. Check our fiber optic cables, and power cycle again.

And THIS time, the server doesn’t power back up. Fans whir for about a second, then an ominous red light I never knew was there shows up. Eeep!

So I call HP. They want me to remove one CPU. Yes, remove one CPU. I tried, and long story short, they dispatch a local guy with a replacement motherboard. “Can you send along a FC controller, in case it’s dead too?” “Nope, not until we diagnose a problem with it.”

Local guy comes out. He’s a sharp guy and I really like him. But the motherboard wasn’t in stock at the local HP warehouse, so he had to have it driven in from Oklahoma City. He gets here with it by about 4:30. At this point the single most important server to the company’s business has been down almost 12 hours.

He replaces the motherboard. The server now powers up — yay! And it POSTs, and it…. doesn’t see the disks. !#$!#$

He orders the FC controller, which is so very much not in stock that they can’t get it to us until 8:30AM the next morning (keep in mind this thing is on a 4-hour 24/7 contract).

Next morning rolls around. Outage now more than 24 hours. He pops the FC controller in, we tweak the SAN settings appropriately, we power up the machine, and….

still doesn’t see any disks, and the SAN switch still doesn’t see any link. EEP!

Even the BIOS firmware tool built into the controller doesn’t see a link, so we KNOW it’s not a software issue. We try plugging and unplugging cables, trying different ports, everything. Nothing makes a difference.

At this point, while he ponders what else he can replace while we start migrating the server to a different blade. We get ERP back up on its temporary home an hour later, and he basically orders us every part he can think of while we’ve bought him some room.

Several additional trips later, he’s replaced just about everything at least once, some things 2 or 3 times, and still no FC link. Meanwhile, I’ve asked my colleague to submit a new ticket to HP’s SAN team so we can try checking of the switch has an issue. They take their sweet time answering until he informs them this morning that it’s been *48 HOURS* since we first reported the outage. All of a sudden half a dozen people at HP take a keen interest in our case. As if they could smell this blog post coming…

So they advise us to upgrade the firmware in the SAN switch, but they also say “we really should send this to the blade group; the problem can’t be with the SAN” — and of course the blade people are saying “the problem’s GOT to be with the SAN”. We try to plan the firmware upgrade. In theory, we can lose a switch and nobody ever notices due to multipathing redundancy. In practice, we haven’t tested that in 2 years. None of this equipment had even been rebooted in 390 days.

While investigating this, we discovered that one of the blade servers could only see one path to its disks, not two. Strange. Fortunately, THAT blade wasn’t mission-critical on a Friday, so I power cycled it.

And it powered back up. And it promptly lost connection to its disks entirely, causing the SAN switches to display the same mysterious error they did with the first blade — the one that nobody at HP had heard of, could find in their documentation, or even on Google. Yes, that’s right. Apparently power cycling a server means it loses access to its disks.

Faced with the prospect of our network coming to a halt if anything else rebooted (or worse, if the problem started happening without a reboot), we decided we’d power cycle one switch now and see what would happen. If it worked out, our problems would be fixed. If not, at least things would go down in our and HP’s presence.

And that… worked? What? Yes. Power cycling the switch fixed every problem over the course of about 2 minutes, without us having to do anything.

Meanwhile, HP calls back to say, “Uhm, that firmware upgrade we told you to do? DON’T DO IT!” We power cycle the other switch, and have a normal SAN life again.

I let out a “WOOHOO!” My colleague, however, had the opposite reaction. “Now we’ll never be able to reproduce this problem to get it fixed!” Fair point, I suppose.

Then began the fairly quick job of migrating ERP back to its rightful home — it’s all on Xen already, designed to be nimble for just these circumstances. Full speed restored 4:55PM today.

So, to cap it all off, within the space of four hours, we had fail:

  • One ERP database
  • ERP server’s motherboard
  • Two fiber optic switches — but only regarding their ability to talk to machines recently rebooted
  • And possibly one FC controller

Murphy, I hate you.

The one fun moment out of this was this conversation:

Me to HP guy: “So yeah, that machine you’ve got open wasn’t rebooted in 392 days until today.”

HP guy: “WOW! That’s INCRED — oh wait, are you running Linux on it?”

Me: “Yep.”

HP: “Figures. No WAY you’d get that kind of uptime from Windows.”

And here he was going to be all impressed.

Review: Silicon Mechanics

Hardware, Reviews

After some hilariously frightening reactions from Dell support to simple problems, and HP becoming aggressively competitive on price, we’ve been using HP servers for a few years now. The hardware is good, and the support, while reasonable, always… pauses… when I mention that we’re running Debian. I try not to let it slip if I don’t have to.

We put in some HP blades a couple of years ago, and I was annoyed to discover that they have discontinued that enclosure and all the blades in it. I decided this was a good time to look at their newer options, as well as at other companies.

Back in July, I had noticed a Silicon Mechanics booth at OSCon. I noticed their slogan “experts included.” That sounds great; we’ve got software experts here, but not hardware experts, and I’d enjoy dealing with a company that knows more about their hardware than I do. I went up to their booth and asked what they’d say about us running Debian on their hardware. “That would be just fine.” “So you’d fully support it when I’m running Debian?” “Sure.” “What about management software – do you have any of that which I’d find annoying to port to Debian?” “Our servers don’t need any management software other than what comes with your kernel.” Good answers.

So, when it came time for us to decide what to do about getting a new server in here, I figured I’d call up Silicon Mechanics and see what they’d recommend. They put me on a conference call with a sales rep and an IT engineer, and wound up recommending a 1U server for us to start with, and an iSCSI storage device to address some of the storage needs we have (both for that server and others). I had heard of iSCSI only vaguely, and asked how it worked, and what the performance would be like compared to our 2Gb FC SAN. I got back intelligent (and correct) answers.

They probably spent 2 hours with me on the phone before we placed an order. I was incredibly happy with their service, level of expertise, and helpfulness. They even did a webinar to demo the management interface on the storage unit for me.

Today, the 1U server arrived. I unboxed it and set it on my desk to configure. First item: set an IP address for the IPMI card. That’s the device that lets me connect to it over a web browser and interact with the console, power cycle it, etc. as if I was there. I set an IP, but somehow couldn’t seem to figure out the username and password for the web interface.

So I called Silicon Mechanics support at the number that was included on the fridge magnet (!) that came with the shipment. Phone rang once. Then a live, capable American answered. No menus, no fuss. I asked my question. He apologized, saying, “I should know that, but I’ll have to look it up… hold on just a bit.” I had my answer about 90 seconds later. He offered to send me the full docs for the IPMI card if I wanted as well.

So I’ve been very impressed with them so far. From what I’ve heard, their iSCSI enclosure ought to be quite something as well. They even helped us spec out a switch that supports trunking for use with it.

I’ll give them a “highly recommended”.

Dot-Matrix Teletype Simulator Update and Request for Teletype Info

Hardware

I recently wrote about wanting to have a teletype. Well, I have since realized that teletypes weigh hundreds of pounds, draw hundreds of watts, and aren’t available on eBay for a reasonable price. Well I knew the hundreds of pounds bit, but still. I pretty well have had to give up on a real teletype.

So, now on to the next best thing: a teletype simulator. Enter the two free dot-matrix printers that found their way to my office earlier this week. One of them even works. I bicycled to the awesome local office supplies store (about 11 miles away) to buy a ribbon for it. This is the place that’s been there since the 1890s. They still stock dot matrix ribbons, typewriter ribbons, and even fanfold paper.

On the project. Linux has its heritage in Unix, which was used with these devices. It can be made to work with them even now. But there’s a trick: teletypes used a bidirectional serial link. Dot matrix printers have no keyboard. So we have to take input from a different device than we send output to.

A simple trick will do for that:

TERM=escpterm telnet localhost > /dev/lp0

Now, here’s the next problem. Dot-matrix printers have a line buffer. They don’t start printing the line at all until they see CR or LF. Makes it annoying for interactive use. So I wrote a quick tool to insert into that pipeline. After a certain timeout after the input stops, it will force the printer to flush its buffer. Took a little while to figure out how to do that, too; turns out there’s a command ESC J that takes an increment for vertical spacing in 1/216 inch, and accepts 0. So I can send \x1BJ\x00 to flush the buffer. I can run it like this:

TERM=escpterm telnet localhost | escpbuf > /dev/lp0

That leaves another problem, though: the printhead is right over the text. (Even though it moves to the right of the printing position, and then moves back left for the next character to print.) I modified the program to roll the paper out a bit, and then reverse feed it to continue printing the line. But that is slow and, I suspect, tough on the stepper motor.

Also, I have crafted a terminfo file for the Epson-compatible dot-matrix printers (which are almost all of them), which can also be found at the above link.

So here’s the question, for anyone that has used a real teletype:

Did the printhead obscure the text there too, or could you see the entire current line at all times?

From Dell, a Uniquely Terrible Experience

Hardware

Ah, Dell. Seeming inventors of the tech support pit of bureaucratic indifferences, inventors of the flamingo pink Inspiron, perpetrators of fraud in New York…

I have, for over a year now, been on a crusade trying to get them to stop sending me their Dell Home and Home Office catalog to my mailbox. It has been a bundle of fun, let me tell you.

They have a nice-sounding privacy policy. It says you can opt out of all their mailings by filling out a form online. Yeah, good luck with that. First of all, there are different forms for different departments at Dell. I’ve filled out them all, multiple times. They do nothing whatsoever. Perhaps they use them as lists of known-good addresses to send new advertisements to, rather than lists of people to remove. Oh well.

Now, unfortunately I feel compelled to bore you with the saga so far, involving telephone hang-ups, broken privacy policies, and the like. But there is a silver lining at the end, in which I submitted a request to the postal service asking them to block Dell from sending me any more mail, and it appears that they are very likely to violate Federal Law any day now.

I have called them about it. Dealt with the old “let me transfer you to the correct department” then hang up on me ploy. Spoken to people that have promised up and down that I’ll be off their list in 30-60 days. It’s always 30-60 days, isn’t it? Very convenient that I can’t tell for 2 months whether or not they’ve processed my request.

I’ve tried their online chat. One of my attempts went like this:

Session Started with Agent (Sneha Ranga)

Agent (Sneha Ranga): “Due to circumstances that have affected Dell Communications I am temporarily unable to pull up any information. The down time is temporary. We apologize for the inconvenience, as we value your time as a customer. Please contact us back after an hour.”

Session Ended

Ah Dell, only you could reach such a pinnacle of customer service. /kicking someone out of a chat room before they have a chance to say a word.

Finally, last fall, I blogged about the situation (that’s the link above). Debbie from Dell read the post and emailed me. Great, I thought. She asked for my address information and catalog information and sent me a removal confirmation:

From: Debbie@Dell.com
Date: Thu, 18 Oct 2007 13:08:18 -0500
To: jgoerzen@complete.org
Subject: RE: Dell mailing list

Thank you, Mr. Goerzen, your request to have the below address
information removed from our marketing lists has been received:

[ my address here ]

We will process your request promptly. However, it may take several
weeks for some changes to take effect. If you are still receiving
catalogs after thirty (30) days feel free to email me. Sorry for any
inconvenience you may have experienced.

Thank you,
Debbie

So that was October. In December, I replied to that message, saying: “I received another mailing today, and it’s been nearly 2 months since your initial message. If there’s anything further you can do, I’d appreciate it.” Debbie said, “I am very sorry Mr. Goerzen, I will resubmit your request.” Guess how successful that was.

So in February, I manage to figure out a way to send in a support ticket without having a Dell system serial number. I wrote:

I keep getting your Dell Home and Home Office catalog. I have tried for months to get off your mailing list. I have called in, talked to people in multiple departments, who have promised to remove me from the list. I have contacted you online. NOTHING IS HELPING. This has gone on for MONTHS.

PLEASE NEVER SEND ME MAIL AGAIN, EVER, AND DO NOT RENT OR SHARE MY NAME.

My address is above.

The code on the mailing I received is: [ snipped ]

The form letter I got back said:

If you are currently receiving our catalog or mailings and would like to be removed, please visit the following web page and select the appropriate link under the “Opt-out of direct mail, phone or fax communications” heading: http://www.dell.com/OptOut

I replied, saying that form didn’t work. Guess what I got back?

Thank you for signing up for Dell Email Subscriptions. Please save this email for your records.

Yes, that’s right. Asking them to take me off their postal mailing lists got them to PUT ME ON their email lists. ARGH.

So they eventually manage to correctly take me off the email list, and of course promise to do the same with the postal list. This back in February.

I contacted them again in March and July, only to have a similar stupidity-laced run-in with clueless form-answer-laden Dell support reps. Each one claimed to have now, finally, and permanently removed me from the list. It never happened, and none of them lifted a finger to find out way, and no amount of begging could make them.

So, here’s the good part.

Junkbusters has spent years educating people on how to get rid of unwanted mail, and documents getting a prohibitory order against the sender. It was originally designed for people that didn’t want to receive obscene advertising mailings, but thanks to the happy fact that one non-adult-mailer challenged a prohibitory order all the way to the Supreme Court, you can now get prohibitory order against anyone. Yes, even Dell. (The supreme court’s ruling even gave an example: you can prohibit a clothing catalog if you want.)

And last month, that’s exactly what I did. The USPS sent me back a copy of the letter they sent to Dell, as well as a second page with instructions on reporting violations. Here’s the letter they sent to Dell:

dell-usps

Somehow I get a chuckle over some Dell mail clerk trying to figure out how an 11-pound laptop is sexually provocative.

From August 25 on, it is a federal offense for Dell to send me another Home and Home Office catalog. This is a branch of criminal law, not civil law. That is, it’s the maybe-go-to-jail branch of law.

How disappointed I was to receive yet another catalog from them today. If only they had waited 5 more days, I could have turned them in now.

Oh well. There’s always next month’s catalog. Let’s just hope the clerk that received the USPS letter removed my name with a better system than everyone else at Dell uses, eh?

Am I being scammed?

tc1100 tablet, , , ,

So today my auction for the tc1100 tablet PC ended. The winning bidder:

  • Is registered to eBay with a Malaysia address
  • Wants me to ship to a Nigeria address (I specifically said in the auction that I do ship internationally, but I ship only to PayPal verified addresses — and I doubt that anybody in Nigera has one)
  • Uses the name “Strong Buyer” in e-mail From line. (There was a real-sounding name in the message from eBay, and the person wants me to ship to a “stepson” in Nigera, also with a real-sounding name)
  • Only registered on eBay today
  • Asked me to send it via DHL, which costs about $250, compared to about $70 with USPS Global Express Mail to Nigeria
  • In the auction, I asked people to “ask the seller a question” to get shipping quotes to their country before placing a bid. This person didn’t (several others did).
  • Has a free throwaway email account (not as well known as hotmail, but the same sort of thing)

I replied to the buyer’s e-mail giving shipping prices to Nigeria and Malaysia, and restating my policy of shipping to only PayPal Verified Addresses.

So what do you all think? Is this a scam?

I was shocked at the amount of scams that sellers on eBay are exposed to these days. I’ve never seen this before, even just a few months ago when I sold my last item on eBay. But with this one, spammers and scammers are using the “ask seller a question” interface. One person tried to get me to use an eBay phishing clone site. Quite a few tried to get me to sell to them off eBay, to people in China, using a non-reputable billpay service. And there was just some generic spam.

So all that, plus the fact that they want me to ship to Nigeria, plus the fact that the person just registered on eBay today, is making me nervous.

So it seems odd, but I can’t quite work out how somebody would actually defraud me here. Also, I’m interested in what I should do if it is a scam.

Now I’m a little annoyed at HP

Hardware, ,

So, a little while ago, I wrote about why I like HP. This week, I’m starting to be annoyed at them.

My employer just bought nearly $100,000 worth of HP hardware. We get a new MSA1500cs Fibre Channel SAN (with redundant controllers, FC switches, disks, etc), a new blade enclosure system, three blades to start with (all of them, at minimum, dual dual-core Opterons with 4GB RAM, and some considerably more), a rack to put all this in, etc.

So we’re starting to set all this stuff up. I’ve got Debian installed on an NFS root for testing the blades and how they interact with the SAN.

The blades have an integrated dual-port QLogic QLA2312 Fibre Channel adapter. The Linux kernel has a built-in driver for this (qla2xxx), which detects it and, so far at least, works fine. We want to run kernel 2.6.17 because it’s the first version where XFS has decent semantics for write ordering to prevent corruption after a power failure. Plus we want at least a 2.6.16.x kernel because we want to run the latest Xen 3.0 on these blades. (Live migration of virtual servers from blade to blade — this will be great.)

But we learn that HP does not support the kernel qla2xxx driver. HP does not say WHY they don’t support it, just that their own driver is the only one that they support.

After plowing through several annoying scripts to get to their driver, I realize why it fails to install: it is OLD. At BEST, 2.6.14 is the most recent kernel it would even compile against (release date: October 2005), and I think the most recent version it supports is more like 2.6.8 (almost TWO YEARS OLD now). They reference a whole bunch of kernel symbols and macros that were removed somewhere between 2.6.8 and 2.6.17.

I sent a ticket to HP support. Their first request was to run their system information gathering tool and send them the results. Fine, that’s reasonable. I did so. Next they say, gee, you’re running Debian, and we don’t support that.

Argh…. If they tried to compile it against 2.6.17.1 on RedHat or SuSE, they’d get the exact same problem. I told them what symbols they were erroneously using, and a simple grep would have showed them that.

Besides, how many customers are going to be pleased with no upgrade path available for 2 years? I wouldn’t want our kernel version to be held hostage to HP’s slow driver development process.

Sigh.

An iPod under Linux

Hardware, Music, Software, ,

I finally purchased my first iPod: a black 60GB iPod video model. I had been holding off for years. The iPod sounded nifty, but I just didn’t quite go there.

The thing that finally won me over was the camera connector. It lets you plug your iPod directly in to a digital camera. The iPod can download photos from the camera to its internal disk without the need for a PC. Very slick.

So anyway, we got the iPod and the camera adapter at the Apple store in Cambridge — a quick subway ride from Usenix. They were out of stock on the FM tuner, so I ordered that online.

The next step was to get the iPod working with Linux. I currently have it working with both music and video. Here’s how I did it.

Why I Like HP

Hardware

I’ve been managing servers professionally for some years now. Support is one of the most important things when you are managing computers for work. You don’t need support to help you out with a printing problem or an e-mail problem. You need support because every minute the machine fails to power up, your company may lose twice the value of the entire machine. Or even more.

My first day job managing servers involved Dell hardware. What a nightmare. I’ve never had a good experience with Dell support, ever.

First off, Dell support never puts me straight through to an intelligent support rep. I don’t care whether I get to the Indian call center or someone in Texas. The first support person I speak to at Dell has less computer aptitude than my grandmother. One conversation I will always remember went like this:

Me: We have a disk in our array that went bad on our Linux server. The red light on the disk itself is on. Please send us a replacement.

Dell: Have you tried rebooting?

Me: No. This is a production server. The reason the disks are redundant is so I don’t HAVE to. Besides, the light ON THE MACHINE ITSELF is on.

Dell: Ah, OK. Have you run scandisk?

Me: No. This is a Linux server, as I told you, and scandisk wouldn’t see a problem anyway since this disk is in an array and the array is still up.

Dell: OK, great. How about you download the diagnostics .exe from our website…

Me: Can’t. We don’t have Windows on this machine. You did say you support Linux when we bought it.

Dell: Ah. Can you right-click on My Computer…

Me: NO. This runs Linux, and the BAD DISK LIGHT ON THE MACHINE IS ON.

Dell: Ah, OK. I wonder if the problem really is that you have a bad disk.

Me: Could be!

Our first HP server purchase happened to be at a time when HP had undercut Dell by several thousand dollars. I liked the hardware, but it wasn’t anything that much more special than Dell.

But what I really like is the support. I haven’t had to call HP support often, but when I do, I am almost always speaking to a live, experienced person within 5 minutes.

With only one exception, all the HP support people I’ve talked to have been very experienced. They all sound like they’ve been working with HP hardware since the late punched card era. They know what is going on and assume that I do too. The HP people don’t make small talk (it *really* ticks me off when someone obviously in Calcutta or something asks me about the weather in Kansas, because you *know* they are reading it off a screen and don’t care). But that’s fine. I’m not calling them to talk about the weather, I’m calling them because my server is down.

We had a bad disk in an array on a HP server once. That conversation went more like this.

HP: Server support. Serial number please?

Me: [gives it to them]

HP: OK. What’s the problem?

Me: The array dropped a disk. The failed disk light is on and the controller logged a disk error.

HP: OK. That’s a 146GB SCSI, right? 15KRPM or 10K?

Me: 15K.

HP: OK. Is 1PM tomorrow good to send out the replacement?

Me: Fine.

HP: OK, your case number is xxxxx. Can you give us directions to your location?

Me: Sure…

So recently we got in our MSL4048 tape library. A very nice unit. And faster than most *disks*. 48 Ultrium3 tapes — 400GB native each — very nice. And a barcode reader built in.

So anyway, one small problem. When you open up a magazine to put tapes in, you can close the unit back up. It says “scanning”, but it doesn’t notice that we’ve changed tapes until we give it a command on the operator panel (yes, this tape drive has a LCD screen built in). This can be worked around, but is annoying and is just waiting to cause confusion. Plus it’s not how it should work.

So I call HP support yesterday.

Turns out this MSL4048 is a brand-new unit. Had only been on the market a few weeks. Our support rep has never seen one or taken calls about one, and they haven’t even given him all the HP technical docs yet. But no matter, he is willing to try to help us out.

He calls me back twice yesterday with tips and questions after speaking to colleagues. He asks intelligent questions, doesn’t bother with the “are you sure you’re putting the tapes in the right way around” or the “is the power cord securely plugged in” crap, and generally doesn’t waste my time. He called me back about four times more today — they duplicated our setup in their lab, right down to the exact firmware version, but didn’t have the problem. Two of those callbacks were apologizing for taking so long, and explaining that they were learning about this machine as they went along. So a HP rep will be out to our location shortly.

Now THAT’S what I call service. No blaming it on someone else, no trying to make me do stupid troubleshooting things, and returning calls.

My *one* bad experience with HP was one time we put a new internal tape drive in the machine, and it was acting flaky. I got the only not-very-experienced HP rep I ever had spoken to that time, and they tried to blame Debian for what turned out to be a bad SCSI cable. (The symptoms weren’t very similar to what I’d expect for a bad SCSI cable, and the cable had been working fine.) Oh HP, you donate to Debian — why don’t you support your hardware under it?

(In fairness, that is the ONLY time they have flinched when I said I run Debian, though it does make them hesitate sometimes)

NiMH Rechargable Batteries and Charger Review

Hardware, Reviews

I’ve been using NiMH batteries for quite a few years now. Ever since my first-ever digital camera came with a free AA charger and four free rechargable NiMH batteries. I’m still using that charger, and it’s been almost 10 years.

I have a few complaints about my existing charger. It won’t charge AAA batteries, and it doesn’t have a discharge feature. Without that, it can be difficult to avoid shortening battery life due to the memory effect which even NiMH batteries are susceptible to. Also, it charges batteries in pairs, which can result in various charging problems when dealing with batteries of uneven charge or uneven storage characteristics.

Also, many of my batteries were old.

So, I set out to find a better charger, and to find the best current NiMH batteries.

The Charger

A little Googling revealed a very useful page at Steve’s Digicams. They suggested the Lacrosse BC-900 Advanced Charger. I ordered this unit from Thomas Distributing and must say it is a very slick unit. It has four main modes: charge, which does a simple charge-until-full; discharge, which will discharge then charge a battery; refresh, which discharges then charges the battery repeatedly until no increase in capacity is measured; and test, which checks the condition of the battery.

The charging and discharging current is fully configurable. I opt for a gentle, slow 200 mA charging current. But others can increase it to many times that. The BC-900 has a built-in temperature cutoff circuit, so it will pause charging if your batteries are about to overheat.

The BC-900 can charge up to 4 AA or AAA batteries simultaneously. Each battery is charged individually, and each battery can have its own mode and charging/discharging current set.

The unit comes with some starter NiMH AA and AAA batteries, plus a carrying case for batteries and the charger. Thomas Distributing also added four more free AA NiMH batteries (nice).

Batteries

I found the Great Battery Shootout site to help with choosing batteries. I eventually chose Maha Powerex batteries and have been happy with them as well. They come in various different capacities (including some larger than are listed on the shootout page) and Thomas Distributing had good prices.

Hope this helps if you’re planning on using rechargable batteries.