WirelessMoves

2D barcodes have been around for a while. In fact, it’s more than 20 years and I mentioned this ‘new’ technology on this blog in 2006. Mind boggling. But some things take their time and it has taken 20 years for the technology to be deployed to get paperless receipts at the bakery. No, I’m not kidding.

Continue reading 2D Barcodes For Paperless Receipts

A little anecdote today about log files and SSD wear: As you might have noticed, I’ve recently done a lot of disk drive benchmarking. The iostat command is a great tool to check how much data is written to a block device over time, and just because I’m curious, I had a look at how much data is written to the main drive of one of my servers since I rebooted it 4 days ago. When I looked I got a shocking number: 400 GB! In 4 days! Now that is impossible I thought at first, perhaps iostat is giving me wrong numbers. So I had a closer look.

Continue reading Beware of Your Log Files

I recently flew to Iceland with Iceland air, and as it was a 3 hour flight from Frankfurt, I was happy to try the on-board Internet to stay connected. For 12 euros a flight, it was perhaps not cheap, but compared to the price of the ticket, it’s almost negligible. As large parts of the trip are over water, satellite connectivity was used. Like the on-board Internet I reviewed last year on Delta when flying to the US, connectivity was provided by Viasat.

Continue reading In-Flight to Iceland with Viasat

And while I’m already at the topic and my test setup is up and running, I also had a go at two of my 2.5″ 4 TB drives and their read and write performance when running differential backups that contain large 50+ GB files, many files in the range of 2-3 MB and many more much smaller document files. My questions: How much slower are these drives compared to the 3.5″ drives that I had a look at so far and can I see a difference between the two drives? As in the previous posts, I’ll keep manufacturer names and drive types out of this, as I wanted to get a general idea rather than praise or blame a particular model.

Continue reading HDD Performance – Part 8 – 2.5″ 4TB Drives – Reading and Writing

The proof lies in the pudding, they say. I’ve initially started this hard disk read and write performance marathon, because the perceived speed of some of my backup hard drives when performing differential backups to them was very slow. Despite being differential, such backups easily go beyond 1.5 TB. So after establishing read and write speed baselines in the previous posts, it’s finally time to look at the speeds of my drives during differential backups.

Continue reading HDD Performance – Part 7 – Differential Write Performance

Wow, this is part 6 of the series already, but I keep getting interesting results. One of the questions that came up during part 5 was how fast data could be read from one of the newer and faster drives when the drive is almost full. To answer this question I ran the following test: Write 16 TB of 50 GB files until the drive is full, then immediately read the drive again. Reading files with a size of 50 GB each should show the maximum average read speed over the drive because there should be lots of chunks for 50 GB on the drive that are consecutive. So here are the results:

Continue reading HDD Performance – Part 6 – 16 TB Write then Read

In my HDD performance analysis series, I would now like to move on and have a look how fast my ‘real world’ data on my backup hard disks can be read. At the moment, I have around 7 TB of data on my backup drives, which consists of a significant amount of very large virtual machine snapshot files with a size in the double digit gigabytes, many smaller sized image files of 2-3 MB and an even bigger number of very small document files of a few hundred kilobytes at most. So how fast can I read such a data mix from hard drives with moving heads?

Continue reading HDD Performance – Part 5 – Reading 7 TB Real World Data

And on we go with another round of looking at Hard Disk Drive performance. After writing 50 GB files to a number of hard drives in episode 2, I decided to have a look how the drives would perform after randomly deleting some about 2.5 TB of 50 GB files and then fill up the empty space again. Before running the tests my expectation was that the outer parts of the disk would be filled first, as write speeds are fastest there and write speeds would gradually reduce over time. The graph at the top of this post that plots the write data rate in MB/s over time shows something else, however.

Continue reading HDD Performance – Part 4 – Writing Large Files to Empty Spaces

In part 1 and 2 of this series, I’ve had a first look at the performance of a number of different hard drives I use to back up large amounts of data. I currently have around 8 TB of data that needs to be backed-up regularly, so speed is of the essence and decides whether a backup cycle takes an hour, half a day, or even more. Before I go on with further measurement results, here’s a quick summary of how I collected my data:

Continue reading HDD Performance – Part 3 – Measurement Setup

Just a quick note today about upgrading my Pixel 6 to from LineageOS 21 to LineageOS 22, which is Android 15 without the Google privacy invading parts:

While standard updates can be done on the phone itself, upgrading from one major version to the next requires side-loading. I’m always a bit weary of doing this, because I’m not keen on bricking a device that I use 24/7, or to reinstall stuff. But LineageOS points out that going from one major version to the next with sideloading will keep the data in place. I’ve done it twice now on my Pixel 6 and it worked both times.

So here is the deal: It only takes about 10 minutes and 2 shell commands on the PC: One adb command to reboot in sideloading mode and one adb command to sideload the latest Lineage ...signed.zip image. And that’s it.

For the full details on how to update from one major version to the next, have a look here for all update options or go straight here for the ‘manual’ major version jump info.