Mirrored drives are also known as a RAID 1 configuration.  It is important to note that running mirrored drives should not be used as a substitute for doing backups.  My motivation for running a RAID 1 is simply that with the drive densities today, I expect these drives to fail.  A terabyte unit is cheap enough that multiplying the cost by two isn’t a big deal, and it gives my data a better chance of surviving a hardware failure.

I purchased two identical drives several months apart – in the hopes of getting units from different batches. I even put them into use staggered by a few months as well.  The intent here was to try to avoid simultaneous failure of the drives due to similarities in manufacture date / usage.  In the end, the environment they are in is probably a bigger factor in leading to failure but what can you do?

Linux has reasonable software raid support.  There is a debate of the merits of software raid vs. hardware raid, as well as which level of raid is most useful.  I leave this as an exercise up to the reader.  The remainder of this posting will be the details of setting up a raid 1 on a live system.  I found two forum postings that talked about this process, the latter being most applicable.

We will start with the assumption that you do have the drive physically installed into your system.  The first step is to partition the disk.  I prefer using cfdisk, but fdisk will work too.  This is always a little scary, but if this is a brand new drive it should not have an existing partition table.  In my scenario I wanted to split the 1TB volume into two partitions, a 300Gb and a 700Gb.

Now let’s use fdisk to dump the results of our partitioning work:

$ sudo fdisk -l /dev/sdd

Disk /dev/sdd: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

Device Boot         Start         End      Blocks   Id  System
/dev/sdd1               1       36473   292969341   83  Linux
/dev/sdd2           36474      121601   683790660   83  Linux


Next we need to install the RAID tools if you don’t have them already:

$ sudo apt-get install mdadm initramfs-tools

Now recall that we are doing this in a live system, I’ve already got another 1TB volume (/dev/sda) partitioned and full of data I want to keep. So we’re going to create the RAID array in a degraded state, this is the reason for the use of the ‘missing’ option. As I have two partitions I need to run the create command twice, once for each of them.

$ sudo mdadm --create --verbose /dev/md0 --level=mirror --raid-devices=2 missing /dev/sdd1
$ sudo mdadm --create --verbose /dev/md1 --level=mirror --raid-devices=2 missing /dev/sdd2

Now we can take a look at /proc/mdstat to see how things look:

$ cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sdd2[1]
683790592 blocks [2/1] [_U]

md0 : active raid1 sdd1[1]
292969216 blocks [2/1] [_U]

unused devices: <none>

Now we format the new volumes. I’m using ext3 filesystems, feel free to choose your favorite.

$ sudo mkfs -t ext3 /dev/md0
$ sudo mkfs -t ext3 /dev/md1

Mount the newly formatted partitions and copy data to it from the existing drive. I used rsync to perform this as it is an easy way to maintain permissions, and as I’m working on a live system I can re-do the rsync later to grab any updated files before I do the actual switch over.

$ sudo mount /dev/md0 /mntpoint
$ sudo rsync -av /source/path /mntpoint


Once the data is moved, and you need to make the new copy of the data on the new degraded mirror volume the live one. Now unmount the original 1TB drive. Assuming things look ok on your system (no lost data) now we partition that drive we just unmounted (double and triple check the device names!) and format those new partitions.

All that is left to do is add the new volume(s) to the array:

$ sudo mdadm /dev/md0 --add /dev/sda1
$ sudo mdadm /dev/md1 --add /dev/sda2

Again we can check /proc/mdstat to see the status of the array. Or use the watch command on the same file to monitor the progress.

$ cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sdd2[1]
683790592 blocks [2/1] [_U]

md0 : active raid1 sda1[2] sdd1[1]
292969216 blocks [2/1] [_U] [>....................] recovery = 0.6% (1829440/292969216) finish=74.2min speed=65337K/sec

unused devices: <none>

That’s all there is to it.  Things get a bit more complex if you are working on your root volume, but in my case I was simply mirroring one of my data volumes.

Unfortunately with the pay-as-you-go plan, there wasn’t any way to get the pictures off the camera.  No data service meant you couldn’t email them from the phone, and the phones bluetooth connectivity seems to be limited to headset profiles.  The data cable was cheap enough on eBay so I thought I’d take a risk and see what could be done with one.

Once I had the cable, it was time to find some software.  BitPim seemed to be the right choice for me (free, and available on Linux).  The Ubuntu repositories have a version that works [sudo apt-get install bitpim].

You’ll want to run it as root, or mess with the /dev entries for USB to grant your user enough rights to access the phone.  The BitPim software handles the capabilities of the M300 in two ways, treating the one phone as effectively two devices.  The first is the “media” version, this allowed me to copy down the pictures from the phone.  The PIM version needed a bit more fiddling as it wasn’t actually detected properly.  I did manage to get it to download the contents of the phonebook from the phone.

Now it turns out that the Bell Mobility firmware for this phone seems to be different enough from the US version that BitPim simply won’t work for writing to the phonebook.  Someone else ran into exactly the same problem as I did. Of course, this was after I managed to delete all 60 phonebook entries that were already stored in the phone. Oops.  I think Jenn has now forgiven me.

I’ll reference the excellent HowardForums for all your cellular information needs. And a pointer to a Samsung page which provides a data access utility (that sadly still fails with the firmware I have).

Late last summer we headed west to Vancouver Island, this is a regular trip as many of my relatives are out that way.  We took a break from visiting family and spent some time in Parksville, specifically down on Rathtrevor Beach.  The first morning we were there, I took a walk with my daughter as the tide was out.  Not five minutes from the cabin I came across a cell phone (pictured above) sitting on the wet sand.

Not seeing anyone around for literally miles, there was a very slim chance I was going to get this back to the owner.  I figured I’d see if it was in working shape or not.  Turns out it didn’t work, and was likely pretty water logged.  Popping it open let me determine the exact model number (Samsung SGH-J706), and based on the SIM card which revealed the carrier it appeared to be a pay as you go phone.

Things started to seem grim when I took a look at the charge port on the phone, not a great sign to see corrosion and salt build up.  It was pretty clear this was very likely junk, but I couldn’t just pitch it into the trash.  It ended up coming home with me where I got a chance to open it up [you could probably tell that was coming..]

The J706 is a slider phone, the screen slides up to reveal a keyboard underneath.  Pretty slick, and I can’t help but think back to The Matrix whenever I have one of these in my hand.  Disassembling the slider was educational, I was able to take it all apart – and put it back together.

Unfortunately, once I had it apart it was pretty clear this wasn’t ever going to work again.  I often wonder if its possible to repair phones that have gotten wet (you see these on eBay from time to time) but a good soak in saltwater looks like a one way ticket for electronics.  The LCD screen seems to have been fairly well sealed, and some of the parts may have been in a working state as well – but it should be evident from the photo that much of it was a complete write-off.

Reassembled and cleaned up, it looked cosmetically fine.  The slider mechanism worked smoothly too.  In the end, I took it into BestBuy’s cell phone trade-in program: I figured that at least they could recycle it properly.  I was up-front with them about the non-working condition of the phone, and they did check it for water damage (there is a little indicator under the battery usually).  The representative told me if it had been in working shape it was worth $60, I figured that was the end of the conversation and told him just to recycle it – but he stopped me and said, let’s see what I can give you for it.  Turns out it was worth $7.61 – I walked away with a gift card feeling pretty lucky.

As you can see from the image, there is still an optional pay service at YOW – but the free one is clearly marked.  I ran a quick speedtest that showed 186kbps down / 26kbps up – not very fast but I don’t expect much for free.  It worked well enough to check twitter and get to my web mail.

For this trip, I was headed to Florida.  The Orlando airport (MCO) also has free wifi, currently it is supported by Google through the holiday season but it is always free.  I’ve been in several US airports which also have free wifi year round, and given that you’ll likely end up waiting around for your flight having internet access is a great way to while away the time.

Ideally any location you end up waiting in for some undetermined amount of time should have (very) cheap or free internet.  My car dealership has free wifi in the waiting area, why not extend this to doctors offices, bus stops, train stations, banks, etc?  Imagine if the government decided that all of its public service centers (think passport office) would have free wifi - I’d be way more willing to sit patiently and wait.

One last note – I’d like to recommend the WiFi Get app for the iPhone/iPod Touch. I think it’s a must have app if you travel with your device.

As an aside, setting up a mail server that uses fetchmail to gather email from the various accounts you have, and using a smarthost configuration to send email does give you most of the benefits of running your own mail server with very few headaches.  The reason to do this might be that you don’t want to trust Google (or someone else) to hold all your email, and/or you don’t want the individual PCs in your house to be the storage for your email (hard to migrate to a new machine, recover from disaster).  This is how I started down the path of running my own true email server. [I keep thinking that someone should create an easy to install NAS add-on that provides exactly this type of email server]

Ok, maybe you don’t want to run your own email server but you’re interested in knowing what is involved… Having a static IP address is handy, mostly to save you from DNS issues.  While you can manage to have a domain name tied to a dynamic IP, many blacklists include the IP ranges used by ISP for dynamic addresses.  Of course you need a domain name, and a DNS server too.  You might also want to consider a secondary MX record, in case your connection goes down.  You’ll also want to check that your ISP isn’t blocking port 25 outgoing, and having a valid reverse DNS is important too.

So you’ve followed the Ubuntu documentation and setup a mail server, great.  Assuming your IP address is “clean” (ie: not on a blacklist), then you can probably send email just fine.  Until you start hitting problems where spam filters have taken a dislike to your system – in my case it was Rogers (email provided by Yahoo) that treating my outgoing as spam.  One solution is to have the recipient add your email address to their address book so they do still get to see your email.  It may still get tagged as [Bulk] but it won’t get lost.  This isn’t a great solution for someone new you want to contact, or a friend who isn’t terribly technical.

It turns out there are some additional measures you can take on the email server side to add more trust.  There are three I’ve implemented:

• Sender Policy Framework (SPF)
• Domain Keys Identified Mail (DKIM)
• Domain Keys

All of them rely on the same basic ‘trick’ of adding a TXT record to your DNS information that serves to validate the email.  This works for the simple reason that spammers tend to use botnets made up of machines without valid DNS records.  SPF simply is a declaration that the IP address sending the email is allowed to send email for the specified domain.  DKIM is an updated version of DomainKeys, but both can be used concurrently and some systems only know one.  Both DKIM and DomainKeys have the email server sign the email with a secret (private) key, and the DNS record has a public key that will validate the signature.

After implementing all three, it turns out Yahoo was still tagging my email as spam.  Very frustrating.  One solution I did consider was to avoid the problem entirely and selectively smarthost email going to rogers.com (and yahoo.com, etc).  In the end, it turns out that Yahoo maintains their own blacklist of sorts and you can request to be removed.  To check this, you need access to a yahoo email account that you can send test messages to.  By examining the header you will see X-YahooFilteredBulk if your IP is on their blacklist, this appears to be independent of the status of your SPF/DKIM/DomainKeys authentication that should show as a pass.  The solution is to fill in the Yahoo form, and be persistent.  Much of the form will not apply but you do need to fill it in with something reasonable (and valid).  After a couple of exchanges over several days I was rewarded with this reply:

While we cannot fully exempt your mail server from our SpamGuard
technology, we have however, made appropriate changes to this IP address
in our database. This should help with delivering mail to the
appropriate Yahoo! folders.

Now email sent to yahoo.com is not tagged as spam or [Bulk] – I did a little victory dance once this happened.

The remainder of this post goes into some of the details of getting the three (SPF, DKIM, DomainKeys) implemented.

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Read the rest of Earning Trust for Your Email Server (341 words)

Well way back in March of this year I got myself a new cell phone, the Nokia 5310.  Now that I’ve had it for a good part of the year, it is overdue for a review posting. Many of my friends have iPhones, BlackBerries, or Android (HTC) phones – giving me some serious gadget lust.  I’ve read other reviews of the 5310 which put it in the smartphone category, and while it is a good phone and has reasonable performance and functionality – it isn’t in the same league as an iPhone.

Let’s start with what I like a lot about the Nokia 5310: Battery life – I charge my phone once a week, Sunday night. Granted I’m not a heavy user of the phone: I’ll log 15mins of calls during a given week, a few text messages, and this week I listened to MP3’s on it for an hour – all on one charge.  My number two feature is the form factor, this phone is small.  Many do not like the candybar style – but for me, I find it works.  Up third is voice / call quality.  My experience with Nokia phones is that they deliver great voice quality, and the 5310 has not let me down.

Ok, on to a few negatives.  The camera is pretty poor, it feel slow and needs bright well lit scenes to take pictures that don’t totally stink.  The display while nice and readable, even in full sun – seems to have two small dust leaks in the bottom corners.  The result of the dust leak is visible in the photos of the phone, it doesn’t impair day to day use but it is sort of annoying.  That’s it for the negatives really, I might complain a little about the buttons not being very positive feeling but I’ve gotten use to them.

The pictures above shows my iPod Touch and the Nokia 5310, it really puts into perspective how small this phone is.

Other features that I’ve found useful: Bluetooth support, both headsets and data connectivity over bluetooth.  This allows me to synchronize the address book with my computer and move pictures, music, or MIDP (java) to and from the phone.  There is also a USB cable interface (good for firmware updates).  It has a standard 3.5mm headphone jack, and it does support MP3 playback (the quality of the music playback was very good).  There is a speaker on the back, and it is quite loud (great for speaker phone calls).  It has a micro SD slot, and I’ve got a 1Gb card in there but it will support up to 16Gb.  The screen resolution is 320×240 and as I mentioned above, it is quite readable in even full daylight.

In summary – it a great little phone.  The battery life is awesome and let’s me taunt my iPhone friends.  I don’t think any of the carriers are offering these anymore, but you can find them used for $120-$175 quite easily (in fact, I purchased mine used).

Now you might have noticed the Apple logo on the screen in the first picture, there is a story behind that.  This specific Nokia 5310 is unlocked, and unbranded (some say debranded).  Read on for the gory details..

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