devil-linux-develop

Re: [Devil-linux-develop] stuff on CD and memory usage

[Heiko Z. <hz...@pr...>]

On 07/14/2003 10:29:06 AM Bruce Smith wrote:
>But, I think it's worth testing on Daemons.  It's very likely that onc=
e
>a program is loaded into memory that it won't need to access the CD
>after it's started.  Filesystem cache should take care of much of this=
.
>We should test this.  If it works without spinning the CD, then I'm al=
l
>for moving possible to CD.

I also think once the daemon is up and  running, there shouldn't be any=

more access to the media.
I'm not certain how it is handled with libraries, does Linux load them
entirely into memory?

Heiko
=

Re: [Devil-linux-develop] stuff on CD and memory usage

[Heiko Z. <hz...@pr...>]

On 07/14/2003 11:11:03 AM Bruce Smith wrote:
>> >But, I think it's worth testing on Daemons.  It's very likely that
>once
>> >a program is loaded into memory that it won't need to access the CD=

>> >after it's started.  Filesystem cache should take care of much of
>this.
>> >We should test this.  If it works without spinning the CD, then I'm=

>all
>> >for moving possible to CD.
>>
>> I also think once the daemon is up and  running, there shouldn't be
>any
>> more access to the media.
>> I'm not certain how it is handled with libraries, does Linux load th=
em
>> entirely into memory?
>
>I think that shared libraries are NOT loaded entirely in memory.

Bad.

>As long as the daemons are doing mostly the same task, they should hav=
e
>all of their required code loaded in memory.  I don't think it'll be a=

>problem.  But it would be worth testing it out.

I would expect a behavior like this.

>If we move everything possible to media, how low do you think we can g=
o?
>I'd love to see the memory requirements drop to 32MB for a bare bones
>firewall.

I did a quick test and moved all binaries and libs from the ramdisk to =
CD
and was able to boot with 40 MB.
I'm pretty sure we could improve this.

cya
  Heiko
=

Re: [Devil-linux-develop] stuff on CD and memory usage

[Bruce S. <bw...@ar...>]

> >I think that shared libraries are NOT loaded entirely in memory.
> 
> Bad.

Since my answer was more of gut feeling than something based on facts, I
ask the question on the programming list of my local LUG.  It has people
that do more programming in Linux than I do.

I got a lot of answers to the question, although I'm not sure which one
is the correct answer.   :-)

It's an interesting read anyway, and it appears I may have been wrong.

Look for the thread with the subject: "Shared libraries & memory usage."

http://www.kalamazoolinux.org/pipermail/programming/2003-July/thread.html

 - BS

Re: [Devil-linux-develop] stuff on CD and memory usage

[Heiko Z. <hz...@pr...>]

On 07/14/2003 10:13:20 PM Bruce Smith wrote:
>> >I think that shared libraries are NOT loaded entirely in memory.
>>
>> Bad.
>
>Since my answer was more of gut feeling than something based on facts,=
 I
>ask the question on the programming list of my local LUG.  It has peop=
le
>that do more programming in Linux than I do.
>
>I got a lot of answers to the question, although I'm not sure which on=
e
>is the correct answer.   :-)
>
>It's an interesting read anyway, and it appears I may have been wrong.=

>
>Look for the thread with the subject: "Shared libraries & memory usage=
."
>
>http://www.kalamazoolinux.org/pipermail/programming/2003-July/thread.h=
tm
>l

Great, now I'm even more confused them before....

Keep me posted, when you get some more information.

Heiko
=

Re: [Devil-linux-develop] stuff on CD and memory usage

[Bruce S. <bw...@ar...>]

> >Look for the thread with the subject: "Shared libraries & memory usage."
> >
> >http://www.kalamazoolinux.org/pipermail/programming/2003-July/thread.html
>
> Great, now I'm even more confused them before....

No kidding.  :-)

> Keep me posted, when you get some more information.

It's an ongoing thread, but I doubt things will get clearer.

IMO, it's going to boil down to some trial & error testing
to see if works or not.

Personally, I really believe we can make daemons run off CD 
without spinning up the CD drive after they start. 

I guess I should move "dialog" to run off CD.  I'm not sure
about the setup script itself, or where to put it if I want 
to move it into $CDDIR....

And I'll also move CIPE to $CDDIR, and watch the light on 
my CD drive when I start a VPN.

Oh, there is another disadvantage to moving daemons to $CDDIR.
Right now we can umount /cdrom and eject it while DL is running.
That won't be possible with running programs/libraries on CD.
I can live with that restriction, but wanted to mention it.

 - BS

Re: [Devil-linux-develop] stuff on CD and memory usage

[Bruce S. <bw...@ar...>]

> >But, I think it's worth testing on Daemons.  It's very likely that once
> >a program is loaded into memory that it won't need to access the CD
> >after it's started.  Filesystem cache should take care of much of this.
> >We should test this.  If it works without spinning the CD, then I'm all
> >for moving possible to CD.
> 
> I also think once the daemon is up and  running, there shouldn't be any
> more access to the media.
> I'm not certain how it is handled with libraries, does Linux load them
> entirely into memory?

I think that shared libraries are NOT loaded entirely in memory.

As long as the daemons are doing mostly the same task, they should have
all of their required code loaded in memory.  I don't think it'll be a
problem.  But it would be worth testing it out.

If we move everything possible to media, how low do you think we can go?
I'd love to see the memory requirements drop to 32MB for a bare bones
firewall.

Around here a lot of places are dumping old Pentium 166 or 200 Mhz boxes
for as cheap as $5 US, and I know many people who are buying them to run
as Linux firewalls.  Some of these PC's don't come with a lot of memory.
Besides, a lot of the "competition" dedicated Linux firewalls, only
require 32MB or even 16MB.

 - BS