LinuxQuestions.org
Latest LQ Deal: Linux Power User Bundle
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 12-28-2007, 06:01 AM   #1
Antryg
LQ Newbie
 
Registered: Oct 2007
Posts: 7

Rep: Reputation: 0
Max swap size use-to-be 2GB on ia32, HAS THIS CHANGED? & on x86_64?


I've found damn-little actual documentation/information about this,
so if someone could point me to something ( like kernel-code that has comments, ferinstance )
that gives correct information, I'd appreciate it.

I've found nothing even remotely recent in tldp.org
( gave up after a WfW-3.1/Linux item ), http://www.linuxquestions.org/questi...ze#post2869823
indicates 2GB is a hard-limit,

RedHat 7.1 had a 2GB hard-limit,
openSUSE ( my distro ) wiki says nothing that I can find on it,
& there's nothing in /usr/src/linux/Documentation/ for some damned reason. . .

Also is it different for ia32 & for x86_64?

==========

Free tip for coders & webmeisterses:
in ~/.bashrc
xmodmap -e "keycode 65 = space underscore nobreakspace endash"
xmodmap -e "keycode 115 = Mode_switch" # Left "Windows"-Key
# What that does is make 4 symbols/key available:
# Normal-spacebar == space
# Shift+space == underscore ( no more reaching up-right for it )
# Mode_switch(left-Win-key)+space == nobreakspace
# Mode_switch+shift+space == endash ( for typesetting:
#use "space endash space", instead of just sticking a
#double-hyphen between phrases: it's MUCH more readably clear! )

# The only key /given/ 4 symbols here, is space-bar ( keycode 65 ).

# see /usr/include/X11/keysymdef.h for the possibilities!!

# use "xev" command-line util to discover the keycodes for
# your multimedia-keyboard & make them thar extra keys useful!

xset r rate 210 35
# saner delay/repeat-rate

These set the keyboard up More Gooder(tm), see. . .

: )
 
Old 12-28-2007, 07:43 AM   #2
Lenard
Senior Member
 
Registered: Dec 2005
Location: Indiana
Distribution: RHEL/CentOS/SL 5 i386 and x86_64 pata for IDE in use
Posts: 4,790

Rep: Reputation: 56
Hmmmm..........

See: http://www.novell.com/linux/techspecs.html
Click on the Kernel Limits if need be.
 
Old 12-28-2007, 08:22 AM   #3
LinuxManMikeC
Member
 
Registered: Nov 2007
Location: Provo, Utah
Distribution: Debian and Ubuntu
Posts: 74

Rep: Reputation: 15
Quote:
Originally Posted by Antryg View Post
The hard limit they were talking about in that thread only refers to the maximum size of a single swap file system. Therefore, you could have 2 2GB swap partitions making 4GB of swap, and so on up to a certain limit (whatever it may be).

Now that SUSE documentation is interesting. A max total of 2TB. From what I can gather from the "32 * 64 GB" notation, I interpret it as a max of 32 swap file systems and a max of 64GB per swap file system. If this is the configuration on all distros, who knows. However, I will soon have 160GB of free space on which to test these limitations. I will report back when I do it (if I remember ).

Last edited by LinuxManMikeC; 12-28-2007 at 10:48 AM.
 
Old 12-28-2007, 10:03 AM   #4
Lenard
Senior Member
 
Registered: Dec 2005
Location: Indiana
Distribution: RHEL/CentOS/SL 5 i386 and x86_64 pata for IDE in use
Posts: 4,790

Rep: Reputation: 56
To LinuxManMikeC;

You should note that this information from SuSE also applies to other versions of Linux as well. The swap space is not limited to 2-GB per swap partition / swap file with the current 2.6 kernel series as the SuSE documentation notes it is now 64-GB per swap partitions and/or swap files.
 
Old 12-28-2007, 10:50 AM   #5
LinuxManMikeC
Member
 
Registered: Nov 2007
Location: Provo, Utah
Distribution: Debian and Ubuntu
Posts: 74

Rep: Reputation: 15
Cool, I figured it was well over 2GB by now. Now, what could I possibly do with 2TB of swap? I barely scratch the surface of my 2GB as it is.
 
Old 12-28-2007, 12:12 PM   #6
Lenard
Senior Member
 
Registered: Dec 2005
Location: Indiana
Distribution: RHEL/CentOS/SL 5 i386 and x86_64 pata for IDE in use
Posts: 4,790

Rep: Reputation: 56
I know which is why mine is only about 1-GB on my 2-GB RAM laptop(minus the shared video memory);
Code:
$ free
             total       used       free     shared    buffers     cached
Mem:       1801520    1163544     637976          0     172184     607104
-/+ buffers/cache:     384256    1417264
Swap:      1116476         64    1116412
 
Old 01-09-2008, 12:28 AM   #7
Antryg
LQ Newbie
 
Registered: Oct 2007
Posts: 7

Original Poster
Rep: Reputation: 0
Thanks All who replied with helpfulness.

64GB is a nice single swap limit, eh?

As for needing it, the machine I'm setting-up has 4GB ECC RAM & 2GB swap, but some programs leak ( all Mozilla apps, e.g. ), and when Thunderbird is eating upwards of 800MB after awhile, and every other app tries-to, yes I sometimes get into trouble for not having enough swap ( crashed for running out, just the other day ).

Some app mem-usage Right Now:
Firefox = 470MB
Thunderbird = 400MB
NVU = 380MB
StoryLines = 300
Zen Updater = 270MB
Konq = 260MB

of course, this particular session, I haven't been into heavy/complex stuff, so these are all small, compared with what sometimes happens. . .

And I remember when "emacs" stood for Eight Megs, And Continuous Swapping!
 
Old 01-09-2008, 02:11 AM   #8
syg00
LQ Veteran
 
Registered: Aug 2003
Location: Australia
Distribution: Lots ...
Posts: 14,834

Rep: Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820Reputation: 1820
That's a theoretical limit - I would be surprised if 2 Gig isn't still the actual (usable) size of each extent for most users.
Redhat did a patch to mkswap for RHEL, but a quick look at the code from kernel.org doesn't show the Redhat modifications have made it upstream.
Don't know about Suse.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
ReiserFS 2Gb maximum file size limit? Cannot copy files bigger than 2Gb ihtus SUSE / openSUSE 2 10-26-2007 10:21 AM
xfsdump max filesize 2GB Crazy_lenny Linux - Kernel 2 09-13-2006 06:31 AM
2GB max memory in Slackware 2.4 kernel? shubb Slackware 11 08-15-2006 01:59 AM
Max swap partition size mindcry Linux - Software 7 11-17-2003 02:53 PM
RHAS2.1 Itainium - Max swap size? Atak Kat Red Hat 3 10-20-2003 06:26 PM


All times are GMT -5. The time now is 02:01 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration