For what it’s worth, the “Download & transfer via USB” feature was applying DRM locked to the key of the specific Kindle device you select, giving you a file that’s incompatible with other devices even if they’re kindles linked to the same Amazon account. For many publishers it also gives files with drastically lower image quality than the Kindle app: about one-fourth to one-third the file size. For a couple examples, a 368MB KFX manga volume has a 125MB AZW3 file and an 8.0MB KFX light novel has a 2.2MB AZW3 file. Those smaller AZW3 files are also similar in size to DRMed EPUB files of the same books from other markets like Kobo and Google Play, so I expect it’s a deliberate choice to limit the quality of formats that are more trivial to strip DRM from.

The best way I’ve found to make personal backups of owned Kindle content is to use a rooted Android device to download everything through the Kindle app, copy the KFX files to a computer, extract the key in a root shell, and then use DeDRM tools on those files with that key.

A quick and dirty shell command I’ve used for that purpose is egrep -ao 'dsn[0-9a-f]{32}' /data/data/com.amazon.kindle/databases/map_data_storage.db. The key is 32 hex characters.

Having a rooted Android device in the first place is the biggest hurdle for being able to do that. This new jailbreak should make it possible to do something similar with e-ink kindles instead.

Rack width includes the rails/ears. That’s where the extra inch you’re referring to comes from. The actual size of equipment you can slide between the rails and inside the rack, not including ears, is about 17.75" for 19" racks and about 8.75" for 10" racks. That is indeed half the width. Or at least within 0.125", but I don’t know how accurate these numbers really are.

MicroATX very much cannot fit in this 10" rack.

Equipment that is “half-rack” or “half-width rackmount” tends to be primarily intended to mount two devices side by side on the same row of a 19" rack, but also can often be mounted in a 10" rack by attaching ears to both sides.

This form factor isn’t actually new. This article is just about someone consolidating resources related to its current market options into simple documentation.

One major perk to this size is that it’s small enough that the vast majority of 3D printers can make plastic mounting brackets for it, making it a lot easier for people (who happen to have access to a 3D printer) to use small low-power gear that isn’t designed for rack mount.

So it’s most popular for people who want to run a few Pi systems, similar small SBCs, or mini PCs similar in size to a Mac Mini, or who want to throw network gear they already own that isn’t designed for racking into a rack. Even ITX systems don’t really seem like a great fit for this in my opinion, though it’s at least possible to fit them.

I’ve been using single-disk btrfs for my rootfs on every system for almost a decade. Great for snapshots while still being an in-tree driver. I also like being able to use subvolumes to treat / and /home (maybe others) similar to separate filesystems without actually being different partitions.

I had used it for my NAS array too, with btrfs raid1 (on top of luks), but migrated that over to ZFS a couple years ago because I wanted to get more usable storage space for the same money. btrfs raid5 is widely reported to be flawed and seemed to be in purgatory of never being fixed, so I moved to raidz1 instead.

One thing I miss is heterogenous arrays: with btrfs I can gradually upgrade my storage one disk at a time (without rewriting the filesystem) and it uses all of my space. For example, two 12TB drives, two 8TB drives, and one 4TB drive adds up to 44TB and raid1 cuts that in half to 22TB effective space. ZFS doesn’t do that. Before I could migrate to ZFS I had to commit to buying a bunch of new drives (5x12TB not counting the backup array) so that every drive is the same size and I felt confident it would be enough space to last me a long time since growing it after the fact is a burden.

For years I’ve been using KeepassXC on desktop and Keepass2Android on mobile. Rather than sync the kdbx file between my devices, I have each device access it through the network. Either via sftp, smb, or nfs, but regardless I need to connect to my home’s VPN to access it when away from home since I don’t directly expose those things to the outside world.

I used to also keep a second copy of the website-tied passwords in Firefox Sync, but recently tried migrating that to Proton Pass because I thought the PIN feature might help, then ultimately decided to move away from that too and start using the KeepassXC-Browser plugin instead. I considered Bitwarden too but haven’t tried it out yet, was somewhat deterred by seeing people say its UI seems very outdated.