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Joined 6 months ago
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Cake day: June 9th, 2024

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  • This is kinda old information, but my understanding was that there were 3 issues with dasiy-chained UPSes.

    The first is that you’re potentially going to cause a ground loop, which is not healthy for the life of anything plugged into those UPSes.

    The second is that there’s a potential for a voltage droop going through from the first to second UPS, which means the UPSes will flap constantly and screw their batteries up, though I’d be shocked if that was necessarily still true for modern high-quality units.

    And of course, the UPS itself won’t be outputting a proper sinewave when it’s on battery, which means your 2nd UPS in the chain will freak out (though again, maybe modern ones don’t have that limitation).




  • really effects performance that much

    Depending on the exact flags, some workloads will be faster, some will be identical, and some will be slower. Compilier optimization is some dark magic that relies on a ton of factors, but you can’t just assume that going from like -O2 to -O3 will provide better performance, since the optimizations also rely on the underlying code as to what they’ll actually make happen… and is why, for the most part, everyone suggests you stop at -O2 since you can start getting unexpected behavior the further up the curve you go.

    And we’re talking low single digit performance improvements at best, not anything that anyone who is doing anything that’s not running benchmarks 24/7 would ever even notice in real world performance.

    Disclaimer: there are workloads that are going to show different performance uplifts, but we’re talking Firefox and KDE and games here, per the OP’s comments.

    Also they do default to a different scheduler, which is almost certainly why anyone using it will notice it feels “faster”, but it’s mainlined in the kernel so it’s not like you can’t use that anywhere else.













  • two commands: dd and resize2fs, assuming you’re using ext4 and not something more exotic.

    one makes a block-level copy of one device to another like so: dd if=/dev/source-drive of=/dev/destination-drive

    the other is used to resize the filesystem from whatever size it was, to whatever size you tell it (or the whole disk; I’d have to go read a manpage since it’s been a bit)

    the dd is completely safe, but the resize2fs command can break things, but you’d still have the data on the original drive, so you could always start over if it does - i’d unplug the source drive before you start doing any expansion stuff.