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Joined 1 year ago
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Cake day: June 14th, 2023

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  • Here’s my messy-cabled 9u rack.

    Image

    It has:

    • Fiber gateway out of view on top of the rack.
    • Switch, which also powers 2 Ruckus APs and 2 other switches.
    • Mikrotik RB5009 router.
    • Raspberry Pi x3 all running Debian Bookworm. I have too many pis right now, running Home Assistant, LibreNMS, Log collection, and a read-only NUT server that orchestrates shutdowns and startups on power loss. I need to consolidate these.
    • 1L PCs. One is on Debian serving media and files. The other is a test server where I’m trying out Immich on openSUSE. I’m considering moving to that and rootless podman for services. To that end I have another of these 1L boxes on my desk trying other options (MicroOS, Fedora IoT, maybe others).
    • HDs. These are backup drives for the 1L server. I keep them powered off except when needed.
    • UPS and a managed, switched PDU.

    Everything is set up for low energy consumption (~90w), remote admin, and recovery from power loss.


  • In terms of language you are correct. But in terms of SI usage it seems to me OP is expressing it correctly. The SI unit prefixes have a name, a symbol and a multiplier. The prefix is a concept that encompasses all three of those attributes. So “kilo” is one way of identifying the 10^3 unit prefix, but the name kilo is not the prefix itself. It’s just the name we use to refer to it. And the symbol k in km is certainly the unit prefix portion of that unit of measure.













  • Copy on write is the difference. As I understand it, a btrfs snapshot takes no space when it’s created (beyond the file system record). The filesystem is always writing changes to file chunks as a new copy of the chunk, which is then recorded as a replacement of the old chunk (which is still present on-disk). So a snapshot tracks all of these later changes, and the file system keeps the old file chunks preserved as long as you keep the snapshot. That’s why you can mount a btrfs snapshot. It just shows you the volume through the lens of all of these saved changes.

    When you delete a snapshot you are then marking these preserved chunks as free space. So that is also quick.