Bullseye default swap partition size?

[John Conover]

I just installed Bullseye, using default "use entire disk" as the HD
configuration from the Graphical Install option on a Live USB SD.

The swap partition size installed on the HD is 1 GB.

Buster, etc., used to be about the size of memory, (8 GB in my case,)
for the swap partition size.

Is there a reason for such small default swap partition size on a 1 TB
HD in Bullseye that I don't know about?

Thanks,

John

--

John Conover, con...@rahul.net, http://www.johncon.com/

[Georgi Naplatanov]

On 1/8/22 18:54, John Conover wrote:
>
> I just installed Bullseye, using default "use entire disk" as the HD
> configuration from the Graphical Install option on a Live USB SD.
>
> The swap partition size installed on the HD is 1 GB.
>
> Buster, etc., used to be about the size of memory, (8 GB in my case,)
> for the swap partition size.
>
> Is there a reason for such small default swap partition size on a 1 TB
> HD in Bullseye that I don't know about?
>

Hi John,

nowadays computers have a lot of RAM and some people (including me)
don't create swap partition or swap file at all. In case of SSD (Solid
State Disk) you can look at this wiki [1]


[1] https://wiki.debian.org/SSDOptimization

Kind regards
Georgi

[Tixy]

On Sat, 2022-01-08 at 19:18 +0200, Georgi Naplatanov wrote:
> On 1/8/22 18:54, John Conover wrote:
> >
> > I just installed Bullseye, using default "use entire disk" as the HD
> > configuration from the Graphical Install option on a Live USB SD.
> >
> > The swap partition size installed on the HD is 1 GB.
> >
> > Buster, etc., used to be about the size of memory, (8 GB in my case,)
> > for the swap partition size.
> >
> > Is there a reason for such small default swap partition size on a 1 TB
> > HD in Bullseye that I don't know about?
> >
>
> Hi John,
>
> nowadays computers have a lot of RAM and some people (including me)

I stopped using swap when Windows 2000 came out [1] and I had a machine
with enough RAM for the programs I used, swap just seemed to slow
things down. At home, I fully migrated to Linux when Debian Lenny was
in testing (2008) and never bothered configuring swap, I couldn't see
the point. The only reason I can see to do so is if it's required for
the system to do suspend to disk (not anything I've used).

[1] If I remember correct, you couldn't actually disable swap, just set
it's size to the minimum of 4MB.

--
Tixy

[Cindy Sue Causey]

Saw the two mentions of having no swap and decided to chime in that I
DO use swap, and so do my laptops accordinly. On a blessed day, I have
8GB ram. To the good or the bad of this particular User CHOICE, I try
to remember to figure in 9 to 13 GB swap for my installations.

"free -m" just now shocked me by saying this HP is only using 89mb of
swap. Genuine shock. I'm used to that number being more like 6GB of
swap in use. I'm impressed because this session has been up about six
hours and has headed into hibernation umpteen number of times the
entire time.

Thank you, Developers! I agree that things swapping in and out
painfully clog the system. Currently running up-to-date Bookworm, by
the way.

Cindy :)
--
Cindy-Sue Causey
Talking Rock, Pickens County, Georgia, USA
* runs with birdseed *

[David Wright]

On Sat 08 Jan 2022 at 14:23:43 (-0500), Cindy Sue Causey wrote:
> On 1/8/22, Georgi Naplatanov <go...@oles.biz> wrote:
> > On 1/8/22 18:54, John Conover wrote:
> >>
> >> I just installed Bullseye, using default "use entire disk" as the HD
> >> configuration from the Graphical Install option on a Live USB SD.
> >>
> >> The swap partition size installed on the HD is 1 GB.
> >>
> >> Buster, etc., used to be about the size of memory, (8 GB in my case,)
> >> for the swap partition size.
> >>
> >> Is there a reason for such small default swap partition size on a 1 TB
> >> HD in Bullseye that I don't know about?
> >

> > nowadays computers have a lot of RAM and some people (including me)
> > don't create swap partition or swap file at all. In case of SSD (Solid
> > State Disk) you can look at this wiki [1]
> >
> > [1] https://wiki.debian.org/SSDOptimization
>
> Saw the two mentions of having no swap and decided to chime in that I
> DO use swap, and so do my laptops accordinly. On a blessed day, I have
> 8GB ram. To the good or the bad of this particular User CHOICE, I try
> to remember to figure in 9 to 13 GB swap for my installations.

I don't use hibernation on my laptop, but only sleep. It has 16GB RAM,
and 16GB swap would remove 33% of its overprovisioning to no purpose.
I have a tower with 14GB of RAM and that has ½GB swap which has never
been used, except when I borrowed it for /boot when trying out a fully
encrypted system.

> "free -m" just now shocked me by saying this HP is only using 89mb of
> swap. Genuine shock. I'm used to that number being more like 6GB of
> swap in use. I'm impressed because this session has been up about six
> hours and has headed into hibernation umpteen number of times the
> entire time.

I would have expected swap usage to drop dramatically when it
hibernates because you've got to have room for what's in memory,
compressed I grant you. Won't it drop a load of RAM caches that
it was holding onto?

> Thank you, Developers! I agree that things swapping in and out
> painfully clog the system. Currently running up-to-date Bookworm, by
> the way.

True, but the alternative is running out of memory, and the OOM killer.
Obviously I don't know what you run that clogs the system. Most of my
machines have much less RAM than the two mentioned, though they get
less memory-intensive use nowadays. Maybe the difference is that
I don't install any DEs here.

Cheers,
David.

[Tixy]

On Sat, 2022-01-08 at 14:24 -0600, David Wright wrote:
[...]

> the alternative is running out of memory, and the OOM killer.
> Obviously I don't know what you run that clogs the system. Most of my
> machines have much less RAM than the two mentioned, though they get
> less memory-intensive use nowadays. Maybe the difference is that
> I don't install any DEs here.

I've always used a DE and no swap, at the moment it's using 850MiB of
RAM running an email program and Firefox with one page open. Opening 10
tabs in Firefox and a music player to get a realistic higher limit of
memory usage and it jumps to 1.5GiB. That still leaves several GiB for
disk caches.

--
Tixy

[Andrew M.A. Cater]

On Sat, Jan 08, 2022 at 08:54:43AM -0800, John Conover wrote:
>
> I just installed Bullseye, using default "use entire disk" as the HD
> configuration from the Graphical Install option on a Live USB SD.
>
> The swap partition size installed on the HD is 1 GB.
>
> Buster, etc., used to be about the size of memory, (8 GB in my case,)
> for the swap partition size.
>

Changed with Bullesye as the default. Rarely, if ever,will a system with
a significant amount of memory hit swap so 2x memory is probably overkill
Hibernation on a laptop is the only thing that might be affected, I think,
and even then,m that's generally to a file rather than generic swap.

Hope this helps. All best, as ever,

Andy Cater

[Also part of the Debian media/images team testing releases.]

[Georgi Naplatanov]

Hi Tixy,

it's possible not to use swap. Debian installer (in expert mode) shows a
warning if the user doesn't create swap partition.

On installed system swap can be turned off with swapoff command and swap
partition can be removed from /etc/fstab manually.

Kind regards
Georgi

[John Conover]

Andrew M.A. Cater writes:
> On Sat, Jan 08, 2022 at 08:54:43AM -0800, John Conover wrote:
> >
> > I just installed Bullseye, using default "use entire disk" as the HD
> > configuration from the Graphical Install option on a Live USB SD.
> >
> > The swap partition size installed on the HD is 1 GB.
> >
> > Buster, etc., used to be about the size of memory, (8 GB in my case,)
> > for the swap partition size.
> >
>
> Changed with Bullesye as the default. Rarely, if ever,will a system with
> a significant amount of memory hit swap so 2x memory is probably overkill
> Hibernation on a laptop is the only thing that might be affected, I think,
> and even then,m that's generally to a file rather than generic swap.
>

Thanks, Andy.

What I was concerned about is the caching pushing the machine into
memory overflow. Is the caching LRU gets replaced? What about mmap(2)
used by many encryption/signature programs for file access pushing the
the machine into memory overflow when cached, etc.?

[David Wright]

Yes, that's obviously a very busy machine.

I just checked the memory use on this desktop after seeing your post
this morning. It has 22 xterms open in fvwm, and there are two remote
ssh logins from my laptop (whence I woke up this desktop). There are
two mutt instances (one reading, one composing this). That all uses:

top - 09:10:40 up 29 min, 22 users, load average: 0.01, 0.02, 0.00
Tasks: 196 total, 1 running, 195 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.2 us, 0.2 sy, 0.0 ni, 99.6 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 7921.6 total, 6472.6 free, 560.2 used, 888.8 buff/cache
MiB Swap: 499.0 total, 499.0 free, 0.0 used. 7063.2 avail Mem

as a baseline. Then I launched FF, which puts up a weather forecast
for the week. I closed that, and clicked on Restore Tabs, which
displays the last page from my previous session yesterday:

top - 09:13:55 up 33 min, 22 users, load average: 0.17, 0.14, 0.05
Tasks: 203 total, 1 running, 202 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.8 us, 0.0 sy, 0.0 ni, 99.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 7921.6 total, 5856.2 free, 897.8 used, 1167.7 buff/cache
MiB Swap: 499.0 total, 499.0 free, 0.0 used. 6698.4 avail Mem

I then rotated through the 194 FF tabs, to produce:

top - 09:22:30 up 41 min, 22 users, load average: 1.76, 1.51, 0.78
Tasks: 208 total, 1 running, 207 sleeping, 0 stopped, 0 zombie
%Cpu(s): 6.2 us, 2.1 sy, 0.0 ni, 75.3 id, 16.4 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 7921.6 total, 1641.6 free, 4750.1 used, 1529.8 buff/cache
MiB Swap: 499.0 total, 499.0 free, 0.0 used. 2737.5 avail Mem

These tabs would mostly be ad and video free, rather than the sites
like newspapers that have multiple videos running (I close those
as soon as I've looked at them).

As you can see, the token swap is untouched, and sits there like a
spare can of petrol in the boot, pretty much whatever normal work
I do. With 6 and 8GB more on two other machines, swap is rather
wasteful, particularly with the SSD one.

To the OP, I would just say that it's impossible for the d-i to
guess which camp you fit into, big swap or small, so if you don't
like what it chooses, you just have to change it yourself. If you
don't do that, then you can always set up a swap /file/ instead.

"Obviously I don't know what you run that clogs the system" (above)
contained a grain of untruth—I know that Cindy Sue uses tabs a lot,
and with different browsers, so I just looked back to find 730+ in
https://lists.debian.org/debian-user/2018/10/msg00416.html

OTOH I use FF on an old laptop, and limit myself to three tabs.
It has 500GB memory and 1GB swap. It churns like hell, and can
take a minute to open a page. Without swap, it just freezes up.
So on thet, it's essential.

(Both machines running buster, which could well be the Final OS
for the old laptop.)

Cheers,
David.

[Tixy]

On Sun, 2022-01-09 at 18:19 +0200, Georgi Naplatanov wrote:
> On 1/8/22 19:38, Tixy wrote:
> > On Sat, 2022-01-08 at 19:18 +0200, Georgi Naplatanov wrote:
> > [1] If I remember correct, you couldn't actually disable swap, just set
> > it's size to the minimum of 4MB.
> >
>
>

> it's possible not to use swap. Debian installer (in expert mode) shows a
> warning if the user doesn't create swap partition.

Thanks, that's what I do. (My comment about 4MB minimum was with regard
to Windows 2000 ;-)

--
Tixy

[Hans]

Am Sonntag, 9. Januar 2022, 18:45:22 CET schrieb Tixy:
However, I believe, hibernating will use the swap partition, so I think, it
might be a good idea, to create a swap partition twice as big as the memory,
if you want to use it.

Of course you can use any other partition for hibernating, but for myself I
used an encrypted swap partition for hibernation in earlier times.

A bigger swap partition will not harm your system, as modern harddrives are
much, much bigger than memory (normally!), most systems are using 16GB or
32GB, not many 64GB (and some 128GB and more) as RAM, but compared to 1TB ,
16GB or even 32GB is rather small.

Maybe some people like me (I personally am using old stuff with debian) are
just using 250GB harddrives, but we are only some dinosaurs to be left.

Normally are 500GB ore higher capacities, so a swap drive does not harm.

Just my opinion....

Best

Hans

[Peter Ehlert]

On January 9, 2022 10:02:21 AM Hans <hans.u...@loop.de> wrote:

Am Sonntag, 9. Januar 2022, 18:45:22 CET schrieb Tixy:

However, I believe, hibernating will use the swap partition, so I think, it 

might be a good idea, to create a swap partition twice as big as the memory, 

if you want to use it.

Double the 64 GB Ram?

I'm a pig, but I seldom see more than 6 GB in use, my swaps are usually about 8.

But we run 24/7 and never hibernate... Old habits are hard to break

[Marco Möller]

On 08.01.22 17:54, John Conover wrote:
>
> I just installed Bullseye, using default "use entire disk" as the HD
> configuration from the Graphical Install option on a Live USB SD.
>
> The swap partition size installed on the HD is 1 GB.
>
> Buster, etc., used to be about the size of memory, (8 GB in my case,)
> for the swap partition size.
>
> Is there a reason for such small default swap partition size on a 1 TB
> HD in Bullseye that I don't know about?
>
> Thanks,
>
> John
>

It might be easy to add a partition for swap now during installation,
observe over time if you indeed need it, and maybe later purge it and
add the free space to some other partition.
It might be difficult to start without a swap partition, but then
realize over time that you need it and getting headaches from where to
free space for it.

My decision on a Laptop with 8GB RAM was to have a swap partition with
8.5 GB RAM, so that I can hibernate to it (8 GB needed for the RAM) and
having a little bit space extra for the hibernation if there would have
been swapped data already. In my system I never observe neither swapping
nor system performance issues, using it for heavy working in the GUI
environment. I configured swapping with the following parameters to have
the system right away knowing that I do not want it to swap, although in
an emergency it would not be forbidden:
file: /etc/sysctl.d/99-myextraconfig.conf
# 1 = minimum swap activity, but not fully disabled as 0 would do it
# so, still helping to avoid running out of RAM
vm.swappiness = 1
# prefer inode/dentry cache to other caches for finding files faster
# (default=100)
vm.vfs_cache_pressure=25


Best wishes,
Marco

[Charlie]

On Sun, 09 Jan 2022 18:57:26 +0100
Hans <hans.u...@loop.de> wrote:

> Am Sonntag, 9. Januar 2022, 18:45:22 CET schrieb Tixy:
> However, I believe, hibernating will use the swap partition, so I
> think, it might be a good idea, to create a swap partition twice as
> big as the memory, if you want to use it.
>
> Of course you can use any other partition for hibernating, but for
> myself I used an encrypted swap partition for hibernation in earlier
> times.
>
> A bigger swap partition will not harm your system, as modern
> harddrives are much, much bigger than memory (normally!), most
> systems are using 16GB or 32GB, not many 64GB (and some 128GB and
> more) as RAM, but compared to 1TB , 16GB or even 32GB is rather
> small.
>
> Maybe some people like me (I personally am using old stuff with
> debian) are just using 250GB harddrives, but we are only some
> dinosaurs to be left.
>
> Normally are 500GB ore higher capacities, so a swap drive does not
> harm.
>
> Just my opinion....
>
> Best
>
> Hans

+1

>
> > On Sun, 2022-01-09 at 18:19 +0200, Georgi Naplatanov wrote:
> > > On 1/8/22 19:38, Tixy wrote:
> > > > On Sat, 2022-01-08 at 19:18 +0200, Georgi Naplatanov wrote:
> > > > [1] If I remember correct, you couldn't actually disable swap,
> > > > just set it's size to the minimum of 4MB.
> > >
> > > it's possible not to use swap. Debian installer (in expert mode)
> > > shows a warning if the user doesn't create swap partition.
> >
> > Thanks, that's what I do. (My comment about 4MB minimum was with
> > regard to Windows 2000 ;-)
>
>
>
>

--
Registered Linux User:- 329524
***********************************************

Love must be as much a light, as it is a flame. ...Henry David
Thoreau

***********************************************

Debian GNU/Linux - Magic indeed.

-----------------------------------------------------

[Charles Curley]

On Sun, 9 Jan 2022 22:27:20 +0100
Marco Möller <ta...@debianlists.mobilxpress.net> wrote:

> It might be difficult to start without a swap partition, but then
> realize over time that you need it and getting headaches from where
> to free space for it.

You can always add a swap file later on. Linux will work with both a
swap partition and a swap file.

--
Does anybody read signatures any more?

https://charlescurley.com
https://charlescurley.com/blog/

[Peter Ehlert]

On January 9, 2022 3:24:18 PM Charles Curley <charle...@charlescurley.com> wrote:

On Sun, 9 Jan 2022 22:27:20 +0100

Marco Möller <ta...@debianlists.mobilxpress.net> wrote:

It might be difficult to start without a swap partition, but then 

realize over time that you need it and getting headaches from where

to free space for it.

Gparted, do a little file management. We all have wasted space somewhere.

You can always add a swap file later on. Linux will work with both a

swap partition and a swap file.

True that.

Later you can Create a swap partition, then edit your fstab to mount on boot. Kinda simple.

[Andrei POPESCU]

On Du, 09 ian 22, 08:58:35, John Conover wrote:
> Andrew M.A. Cater writes:
> > On Sat, Jan 08, 2022 at 08:54:43AM -0800, John Conover wrote:
> > >
> > > I just installed Bullseye, using default "use entire disk" as the HD
> > > configuration from the Graphical Install option on a Live USB SD.
> > >
> > > The swap partition size installed on the HD is 1 GB.
> > >
> > > Buster, etc., used to be about the size of memory, (8 GB in my case,)
> > > for the swap partition size.
> > >
> >
> > Changed with Bullesye as the default. Rarely, if ever,will a system with
> > a significant amount of memory hit swap so 2x memory is probably overkill
> > Hibernation on a laptop is the only thing that might be affected, I think,
> > and even then,m that's generally to a file rather than generic swap.
>

> What I was concerned about is the caching pushing the machine into
> memory overflow. Is the caching LRU gets replaced? What about mmap(2)
> used by many encryption/signature programs for file access pushing the
> the machine into memory overflow when cached, etc.?

I'd reword Andy's "a system with a significant amount of memory" to
something like "unless the system is seriously RAM constrained".

$ free -m
total used free shared buff/cache available
Mem: 3938 1481 984 277 1472 2150
Swap: 2047 0 2047


$ /sbin/swapon -s
Filename Type Size Used Priority
/dev/zram0 partition 524284 0 100
/dev/zram1 partition 524284 0 100
/dev/zram2 partition 524284 0 100
/dev/zram3 partition 524284 0 100


This is an ARM64 laptop running LXDE with two instances of
xfce4-terminal each with its own tmux (one of them running two instances
of neomutt), plus Firefox with lots of tabs (admittedly most of them
inactive -- 20 or so active tabs is the usability limit) everything
running from a 32GB USB stick.

The electricity consumption is probably minimal, so I never bothered
with hibernating, I only let lightdm turn of the screen when it's not in
use.

Kind regards,
Andrei
--
http://wiki.debian.org/FAQsFromDebianUser