Re: swap-fle on arm64, need to disable, how?
On 9/30/23 23:22, hw wrote:
On Sat, 2023-09-30 at 18:29 -0400, gene heskett wrote:
On 9/30/23 13:28, Matthias Böttcher wrote:
sudo dphys-swapfile swapoff
sudo systemctl stop dphys-swapfile.service
sudo systemctl disable dphys-swapfile.service
.
However that did give me a clue about getting rid of zram0, which has
been done now, thank you. Now I hope to uncomment the SSD line in fstab.
Well, zram is the way to go; why would you still use swap partitions
or swap files instead? Are you deliberately trying to wear out your
SSDs or to slow down your computer?
zram is probably the way to go for board with lots of dram. Something
the pi's don't have. My only pi is an early rpi4b, Claims 2G, shows
1.8G. I tend to do big things with it. I was first on this ball of rock
and water to make linuxcnc and that pi, run an 80 yo lathe I converted
to cnc controls. Teaching that lathe tricks it could not do when it
shipped out out Chicago circa 1946.
To steal over a gig for zram style swap does not make any sense to me.
There's compression and decompression involved too I'm told. By putting
swap on a 10G partition on a 500meg a second SSD, brings big memory into
the picture, allowing that little card to do big things without running
out of memory. I've built its own realtime kernels on it is 23 minutes,
linuxcnc with its docs including some translations ran it 200megs into
that zram and took nearly 4 hours. With real swap back on buster, just
under an hour. Just the English docs are now over 1000 pages of dead
tree. What we really need are translators. Except for the de stuff,
other languages are quite incomplete, but this old Iowa farm kid doesn't
speak anything but English, and doesn't even touch type.
I'm not a "working shop" other than my own product, just a retired bc
engineer. I basically serve as the canary in the coal mine for linuxcnc,
keeping that pi up to date with the git master & looking for
showstoppers. This gets done several times a week, doing a decent job of
keeping me out of the bars.
Fedora has it by default since a while, and at first I thought it's a
very stupid idea. In practise, I can't be bothered anymore to create
these annoying swap partitions. They're only a waste of disc space.
There haven't been any issues with it, and when the machine runs out
of memory, using swap partitions or swap files isn't going to fix
that.
But with zram taking over half its memory, its into swap and slowing
down quicker, and plumb out of memory for big jobs, when it could still
be working fine with bigger, albeit probably slower than zram, swap.
I've no clue how much the zram compression slows it in terms of thru put.
I wiped out the git clone of linuxcnc by re-arranging that SSD
yesterday, but I'll do another build later today and see how long it
takes with real swap.
Thank you. Take care & stay well.
.
Cheers, Gene Heskett.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>
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