empty the swap partition? slow internet
I am running a 48MB 133Mhz machine with Suse 8.0 It has worked fine on the net until today. The spped slowed down often to less than 100 bytes per second, and the hard drive thrashed for hours. Questions: Should the swap partition be empty upon cold boot? If so what is the command to test it to see how full it is, and to empty it, and in which boot file should it go? It took me 8 hours to look at about 30 web pages of a ecommerce site. I never was able to make my purchases. Sometimes, it would take 15 minutes to bring a page up. more ram is an easy answer, but this is an old machine, and 48MB is overkill for other work. what has changed? --- John Sowden American Sentry Systems. Inc. 1221 Andersen Drive San Rafael, CA 94901 U.L. Listed Central Station Alarm Service Serving the San Francisco Bay Area Since 1967 mail@americansentry.net http://www.americansentry.net
The Saturday 2005-04-23 at 20:35 -0700, John Sowden wrote:
I am running a 48MB 133Mhz machine with Suse 8.0 It has worked fine on the net until today. The spped slowed down often to less than 100 bytes per second, and the hard drive thrashed for hours.
Questions: Should the swap partition be empty upon cold boot? If so what is the command to test it to see how full it is, and to empty it, and in which boot file should it go?
There is no such thing, and no need either. Your problem must be something else.
It took me 8 hours to look at about 30 web pages of a ecommerce site. I never was able to make my purchases. Sometimes, it would take 15 minutes to bring a page up. more ram is an easy answer, but this is an old machine, and 48MB is overkill for other work. what has changed?
My guess is that those pages are using java, and java needs a lot of memory. As you don't have it, it swaps a lot. I had the same problem three years back, and had to upgrade the computer, no other way: memory for old computers is prohibitive. -- Cheers, Carlos Robinson
Carlos, John, On Sunday 24 April 2005 05:36, Carlos E. R. wrote:
The Saturday 2005-04-23 at 20:35 -0700, John Sowden wrote:
I am running a 48MB 133Mhz machine with Suse 8.0 It has worked fine on the net until today. The spped slowed down often to less than 100 bytes per second, and the hard drive thrashed for hours.
Questions: Should the swap partition be empty upon cold boot? If so what is the command to test it to see how full it is, and to empty it, and in which boot file should it go?
There is no such thing, and no need either. Your problem must be something else.
It took me 8 hours to look at about 30 web pages of a ecommerce site. I never was able to make my purchases. Sometimes, it would take 15 minutes to bring a page up. more ram is an easy answer, but this is an old machine, and 48MB is overkill for other work. what has changed?
My guess is that those pages are using java, and java needs a lot of memory. As you don't have it, it swaps a lot. I had the same problem three years back, and had to upgrade the computer, no other way: memory for old computers is prohibitive.
As a blanket statement, "Java [software] needs a lot of memory" is not particularly accurate. As a Java programmer who has worked on some programs that _do_ use a lot of memory (by their nature, whether implemented in Java or something conventionally thought of as more parsimonious), I've noticed that when the program's demand for memory approaches the limit imposed by the Java Virtual Machine at the time it was launched, performance degrades very badly. This happens because the JVM must perform more and more garbage collection. This will not lead to swapping unless the Java heap limit is set large enough to cause the OS in which it's running to page. The default JVM heap limit won't do that on any system that's not already on the brink of thrashing. However, I now look back and see that John says "48 MB is overkill." From that perspective, Carlos is right. You'll have trouble running non-trivial Java code with so little RAM. In fact, I don't see how you're running a GUI environment of any sort in so little RAM. Generally speaking, the solution to such a problem with Java software is to increase the JVM maximum heap size by specifying the -Xmx<size> option, but I don't know how to do that for applets running within a browser. John, which browser and which JVM release are you using?
Carlos Robinson
Randall Schulz
Randall, El Dom 24 Abr 2005 17:31, Randall R Schulz escribió:
Generally speaking, the solution to such a problem with Java software is to increase the JVM maximum heap size by specifying the -Xmx<size> option, but I don't know how to do that for applets running within a browser.
I believe that you can't do that on an applet for applet basis. But you can do it for the VM running in the browser, specifying the parameters as VM runtime values in the Java Plug-In Control Panel. So, if you are delivering an applet-based application on a corporate intranet, this is an option. Regards, -- Andreas Philipp Noema Ltda. Bogotá, D.C. - Colombia http://www.noemasol.com
Andreas, On Sunday 24 April 2005 15:39, Andreas Philipp wrote:
Randall,
El Dom 24 Abr 2005 17:31, Randall R Schulz escribió:
Generally speaking, the solution to such a problem with Java software is to increase the JVM maximum heap size by specifying the -Xmx<size> option, but I don't know how to do that for applets running within a browser.
I believe that you can't do that on an applet for applet basis. But you can do it for the VM running in the browser, specifying the parameters as VM runtime values in the Java Plug-In Control Panel. So, if you are delivering an applet-based application on a corporate intranet, this is an option.
Two things about that: 1) I see no ability to adjust memory allocation in the Java control panel (on Windows). 2) I've never seen a Java control panel for Linux. Does it exist?
Andreas Philipp
Randall Schulz
Randall, El Dom 24 Abr 2005 19:04, Randall R Schulz escribió:
Two things about that:
1) I see no ability to adjust memory allocation in the Java control panel (on Windows).
On the 'Advanced' tab you wiil find a text field 'Java runtime parameters' or so. Mine is in Spanish so I have to translate back to English. On this field it is possible to pass runtime parameters to the Plug-In VM.
2) I've never seen a Java control panel for Linux. Does it exist?
Sure it does. I am running it right now. I start mine with /usr/java/j2sdk1.4.2_06/jre/bin/ControlPanel. -- Andreas Philipp Noema Ltda. Bogotá, D.C. - Colombia http://www.noemasol.com
Andreas, On Sunday 24 April 2005 17:11, Andreas Philipp wrote:
Randall,
El Dom 24 Abr 2005 19:04, Randall R Schulz escribió:
Two things about that:
1) I see no ability to adjust memory allocation in the Java control panel (on Windows).
On the 'Advanced' tab you wiil find a text field 'Java runtime parameters' or so. Mine is in Spanish so I have to translate back to English. On this field it is possible to pass runtime parameters to the Plug-In VM.
2) I've never seen a Java control panel for Linux. Does it exist?
Sure it does. I am running it right now. I start mine with /usr/java/j2sdk1.4.2_06/jre/bin/ControlPanel.
Hmmm... This is a bit odd, actually. According to Locate, this program was present in my old 9.1 installation. In my 9.3 installation, where I have both 1.4.2 and 1.5.0 of Java instaled, only the 1.5.0 version includes it. Another oddity is that there is the grossly generic entry in /usr/bin called ControlPanel, which if you follow the symbolic links through /etc/alternatives, do lead to the ControlPanel in the 1.5.0 bin directory. Thanks for putting me on to this.
Andreas Philipp
Randall Schulz
On Sunday 24 April 2005 06:31 pm, Randall R Schulz wrote:
However, I now look back and see that John says "48 MB is overkill."
From that perspective, Carlos is right. You'll have trouble running
non-trivial Java code with so little RAM. In fact, I don't see how you're running a GUI environment of any sort in so little RAM.
Generally speaking, the solution to such a problem with Java software is to increase the JVM maximum heap size by specifying the -Xmx<size> option, but I don't know how to do that for applets running within a browser.
John, which browser and which JVM release are you using?
John didn't say he was using java. That was Carlo's idea. In my opinion he was lucky to get a GUI environment installed at all in 48M, much less to get it to run. The answer is more resources, both cpu and memory. Without that, it will never run well.
The Sunday 2005-04-24 at 18:40 -0400, Bruce Marshall wrote:
John didn't say he was using java. That was Carlo's idea.
An educated guess, based in the fact that I had the exact same problem three years ago, and in what he said: |> It took me 8 hours to look at about 30 web pages of a ecommerce site. ecommerce pages are usually java based.
In my opinion he was lucky to get a GUI environment installed at all in 48M, much less to get it to run.
Not at all. I have here another with even less, 32M. It did graphics since the day I bought it, and keeps doing it. -- Cheers, Carlos Robinson
On Sunday 24 April 2005 15:31, Randall R Schulz wrote:
Carlos, John,
On Sunday 24 April 2005 05:36, Carlos E. R. wrote:
The Saturday 2005-04-23 at 20:35 -0700, John Sowden wrote:
I am running a 48MB 133Mhz machine with Suse 8.0 It has worked fine on the net until today. The spped slowed down often to less than 100 bytes per second, and the hard drive thrashed for hours.
Questions: Should the swap partition be empty upon cold boot? If so what is the command to test it to see how full it is, and to empty it, and in which boot file should it go?
There is no such thing, and no need either. Your problem must be something else.
It took me 8 hours to look at about 30 web pages of a ecommerce site. I never was able to make my purchases. Sometimes, it would take 15 minutes to bring a page up. more ram is an easy answer, but this is an old machine, and 48MB is overkill for other work. what has changed?
My guess is that those pages are using java, and java needs a lot of memory. As you don't have it, it swaps a lot. I had the same problem three years back, and had to upgrade the computer, no other way: memory for old computers is prohibitive.
As a blanket statement, "Java [software] needs a lot of memory" is not particularly accurate.
As a Java programmer who has worked on some programs that _do_ use a lot of memory (by their nature, whether implemented in Java or something conventionally thought of as more parsimonious), I've noticed that when the program's demand for memory approaches the limit imposed by the Java Virtual Machine at the time it was launched, performance degrades very badly. This happens because the JVM must perform more and more garbage collection. This will not lead to swapping unless the Java heap limit is set large enough to cause the OS in which it's running to page. The default JVM heap limit won't do that on any system that's not already on the brink of thrashing.
However, I now look back and see that John says "48 MB is overkill." From that perspective, Carlos is right. You'll have trouble running non-trivial Java code with so little RAM. In fact, I don't see how you're running a GUI environment of any sort in so little RAM.
Generally speaking, the solution to such a problem with Java software is to increase the JVM maximum heap size by specifying the -Xmx<size> option, but I don't know how to do that for applets running within a browser.
John, which browser and which JVM release are you using?
Carlos Robinson
Randall Schulz
First, thanks for all the feedback. I am running the Konq that came with Suse 8.0. I do not know which JVM I am running, but I did not install it, so I assume it is the one that came with Suse 8.0. If you tell me how, I will check that (and learn how at the same time!) re: 48MB is overkill _for other work_, I was referring to MS-DOS 7.0 that I use on the other computers in our office, and this one (boots DOS/Linux), as well as my 128MB 1.3GHz Suse 8.2 machine (also boots DOS/Linux). I run our mission critical and business stuff on DOS, although I am in the process of re-writing all spreadsheets to open office. re: this thrashing issue, it seems to happen after I have been on the net for several hours, not when the machine is first turne on. Also I went back to the electronics supplier site (mpjs.com) after shutting off the machine. It degraded after about 15 minutes. --- John Sowden American Sentry Systems. Inc. 1221 Andersen Drive San Rafael, CA 94901 U.L. Listed Central Station Alarm Service Serving the San Francisco Bay Area Since 1967 mail@americansentry.net http://www.americansentry.net
On Sun, 2005-04-24 at 15:56 -0700, John Sowden wrote:
First, thanks for all the feedback.
I am running the Konq that came with Suse 8.0. I do not know which JVM I am running, but I did not install it, so I assume it is the one that came with Suse 8.0. If you tell me how, I will check that (and learn how at the same time!) re: 48MB is overkill _for other work_, I was referring to MS-DOS 7.0 that I
I beg to differ with you. Yes 48M is overkill for DOS, but it is way too little for a newer OS such as linux. This is why you end up with the harddrive thrashing after it has been running for a short time, it is swapping -a lot-. You could not even begin to install and run MS2000 on this machine. Your choice is to either -only- run DOS or add more ram for running linux unless you want to go back to something like SuSE 6.2 that has a smaller foot print.
use on the other computers in our office, and this one (boots DOS/Linux), as well as my 128MB 1.3GHz Suse 8.2 machine (also boots DOS/Linux).
My guess is that you don't have these problems on this machine because it has enough ram installed.
I run our mission critical and business stuff on DOS, although I am in the process of re-writing all spreadsheets to open office. re: this thrashing issue, it seems to happen after I have been on the net for several hours, not when the machine is first turne on. Also I went back to the electronics supplier site (mpjs.com) after shutting off the machine. It degraded after about 15 minutes.
-- Ken Schneider UNIX since 1989, linux since 1994, SuSE since 1998 "The day Microsoft makes something that doesn't suck is probably the day they start making vacuum cleaners." -Ernst Jan Plugge
John, On Sunday 24 April 2005 15:56, John Sowden wrote:
...
First, thanks for all the feedback.
I am running the Konq that came with Suse 8.0. I do not know which JVM I am running, but I did not install it, so I assume it is the one that came with Suse 8.0. If you tell me how, I will check that (and learn how at the same time!) re: 48MB is overkill _for other work_, I was referring to MS-DOS 7.0 that I use on the other computers in our office, and this one (boots DOS/Linux), as well as my 128MB 1.3GHz Suse 8.2 machine (also boots DOS/Linux). ...
I unerstood what you meant by the "overkill" statement. But I'm afraid you're asking too much from the computing hardware you're using. You don't have enough memory or enough CPU cycles (per second). Another thing to keep in mind is that Java gets its speed from translating the program's so-called "byte-codes" (machine instructions for the Java Virtual Machine) to native machine instructions on an on-demand basis. This takes more memory (not accounted for in the -Xmx<size> option, by the way), and if memory is not available for that purpose, then this JIT ("just in time") compilation process is impaired and you must run more of the program in fully interpreted mode, which can be pretty slow. If this is your only alternative for accessing these on-line resources, then you're going to have make up the difference with patience. I'd consider myself lucky to get any of this working at all!
John Sowden
Randall Schulz
John Sowden wrote:
I am running a 48MB 133Mhz machine with Suse 8.0 It has worked fine on the net until today. The spped slowed down often to less than 100 bytes per second, and the hard drive thrashed for hours.
Questions: Should the swap partition be empty upon cold boot? If so what is the command to test it to see how full it is, and to empty it, and in which boot file should it go?
It took me 8 hours to look at about 30 web pages of a ecommerce site. I never was able to make my purchases. Sometimes, it would take 15 minutes to bring a page up. more ram is an easy answer, but this is an old machine, and 48MB is overkill for other work. what has changed?
Swap is normally managed transparently, so you don't have to do anything. I'd suspect your problem lies elsewhere. What does "cat /proc/meminfo" show?
participants (7)
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Andreas Philipp
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Bruce Marshall
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Carlos E. R.
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James Knott
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John Sowden
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Ken Schneider
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Randall R Schulz