pitter patter on the keyboard

I recently purchased an LG blu-ray burner which was DOA.

I might just be an idiot, and things may have changed by now but I wasted a solid half hour of my life not finding anywhere to RMA the drive on their Canadian consumer products site.

For your benefit, so you do not end up on hold with consumer support for 20 minutes as I did, the location of the RMA portal:

https://www.lgrepairportal.com

Recovering from a disk failure in a software RAID is a very straightforward and easy process. If your server, chipset and kernel module allow, it may be possible to replace the offending drive without downtime. This is generally not the case with cheap SATA setups, where the server will have to be powered down for the drive replacement. Although it might be safe to remove a SATA drive while the system is running your kernel module may not support recognising the new drive without reloading or rebooting.

The failed drive will have to be identified. This is a very easy process with hardware controllers (typically an indicator light will flash on the failed drive) but not quite as simple when using software RAID. The surefire way to identify a drive is by serial number; find the device node (either through cat /proc/mdstat or dmesg) then run either:

# hdparm -i /dev/{disk node}

# smartctl -a /dev/{disk node}

If your configuration does not support hot swapping power down the machine and replace the bad drive. If it does, you may need to remove other partitions on the target disk from their respective arrays:

# mdadm -f /dev/{md node} /dev/{partition node}

will mark the partition as FAILED, then it can be removed from the set:

# mdadm -r /dev/{md node} /dev/{partition node}

If you are running swap space on the failed drive be sure to disable it with swapoff before removing the disk.

It should be possible to boot the machine off of the remaining set but if you run in to trouble it is just as easy to perform these operations from a livecd.

First we need to copy the partition table from one of the healthy disks exactly. Let sda represent a healthy disk and sdb represent the new one:

# sfdisk -d /dev/sda | sfdisk /dev/sdb

Now we need to add the new partition(s) to our existing RAID set. If you are booting off a livecd and your sets were not automatically configured on boot (they should have been) use mdadm –assemble to assemble them. Then:

# mdadm /dev/md0 -a /dev/sdb1

for each set and partition which needs to be added.

We can watch the resynchronization status with:

# watch cat /proc/mdstat

Personalities : [raid1] [raid6] [raid5] [raid4]
md1 : active raid1 sdb2[2] sda2[1]
      243922816 blocks [2/1] [_U]
      [================>....]  recovery = 83.8% (204426880/243922816) finish=58.3min speed=11271K/sec

md0 : active raid1 sdb1[0] sda1[1]
      272960 blocks [2/2] [UU]

The resync process will slow down considerably if there is heavy disk i/o at the same time and you can expect below-average performance until recovery has completed.

My blank Das Keyboard Model S has pretty much had its last run. Purchased last March, it had seen the last of my days as a smoker and consequentially the switches have become a little gummy. Now that everyone and their uncle has a blank keyboard I pondered what would have the same level of bad-assery while being unique. Thanks to WASD Keyboards‘ custom laser etching and engraving it’s now easy and affordable for anyone to design their own keycaps and it didn’t take me very long to think of using bar codes.

WASD lets you choose from a selection of mechanical Cherry MX switches; I stuck with the Blues because they’re what I know and love. You also get to choose from a range of keycap colours; using their flash-based keyboard designer it’s easy to mix and match to get your ideal colour coding. The etched (contrasting colour) or engraved (indented) design can also be done in the flash designer but for full customization PDFs, Adobe Illustrator and Corel Draw documents based on provided templates are accepted. This is the route I would have to take to get bar codes.

Not knowing anything about Illustrator before diving in, my alignments are a little off in some places but not to the point where it’s noticeable. To make things go swiftly I used a font rather than generating individual bar codes for each key. Since Code 128 requires start, stop and check characters (which would take up far too much space on many keys) none of these bar codes are scannable with a bar code reader but the font does create valid individual character codes. Ideally, characters should be converted to objects before submission but being useless with Illustrator I submitted the font in my order comments and the staff were kind enough to play along and install it. You can grab your copy at http://k-fox.net/code128.ttf

Much to my surprise my order was already being worked on the evening it was submitted and it shipped two days later. That’s some seriously fast turnaround for any sort of custom order. The keyboard itself is built like a tank and I’m overjoyed at the feel of my fresh, clean Cherry Blues!

Great job, WASD – you’ve landed a repeat customer.