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Author: Steve Litt
To: dng
Subject: Re: [DNG] running with separate / and /usr
Antony Stone said on Mon, 16 Jan 2023 16:59:38 +0100

>Without wishing to open a large can of annelids, can someone tell me
>why anybody actually cares about this? What is the use case for
>having /usr on a separate partition - why does anybody want it?

A separate /usr is a 20th century thing. Back then, spinning rust
drives were typically 20GB or less, which means they might not be able
to contain the contents of /usr. Also back then, you could save lots of
disk space by having one /usr, with all computers mounting it with NFS,
thus removing the need to make space for /usr on every computer.

But today the smallest practical SSD/NVMe you can buy without paying a
premium per GB is 250GB. Your 40GB /usr (for a very well equipped
poweruser desktop) is 1/6 of the 250GB, so if you fstrim with
reasonable frequency, you'll get outstanding wear leveling for (I
would guess) at least 3 years. A 1TB SSD/NVMe will cost you less than
$105 at Newegg. 40GB is 1/24 of a 1TB.

I guess one could make the point that a remote /usr would simplify
admin, but back in the 20th Century we didn't have Salt and Ancible and
all that stuff that makes multi-machine standardization simple.

So my opinion is that in 2023 there's little reason to have a /usr
anywhere but root ( / ).


Steve Litt
Autumn 2022 featured book: Thriving in Tough Times