Hi there --
I am running Fedora Core 5 that was hardened by Bastille Linux on a system with 1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached RAM is going up. This results in the amount of free memory going down to where there is almost nothing left. The end result has been the system to periodically hanging, which forces me to reboot the server.
What can I do to correct this problem? Thanks.
Have you ran a memtest86+ on the box?
On Wed, 2006-10-25 at 10:31 -0400, Kaplan, Andrew H. wrote:
Hi there --
I am running Fedora Core 5 that was hardened by Bastille Linux on a system with 1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached RAM is going up. This results in the amount of free memory going down to where there is almost nothing left. The end result has been the system to periodically hanging, which forces me to reboot the server.
What can I do to correct this problem? Thanks.
Hi there --
Thanks for your reply. No I have not. I have downloaded the app and will create a boot disk in order for it to run. I'll let you know what I discover during the test.
-----Original Message----- From: fedora-list-bounces@redhat.com [mailto:fedora-list-bounces@redhat.com]On Behalf Of Adam Hough Sent: Wednesday, October 25, 2006 10:34 AM To: For users of Fedora Core releases Subject: Re: Memory staying in cached status -- Possible Memory Leak
Have you ran a memtest86+ on the box?
On Wed, 2006-10-25 at 10:31 -0400, Kaplan, Andrew H. wrote:
Hi there --
I am running Fedora Core 5 that was hardened by Bastille Linux on a system
with
1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached
RAM
is going up. This results in the amount of free memory going down to where
there
is almost nothing left. The end result has been the system to periodically hanging, which forces me to reboot the server.
What can I do to correct this problem? Thanks.
Hi there --
I ran a memtest86+ scan on the box, and there were no errors reported by application. At this point it would appear there is a resource hog that is causing this issue. What utility can I use to track the usage of the various programs on the system.
The top utility comes to mind, but what options would I use including the ability to output the results to a file?
-----Original Message----- From: fedora-list-bounces@redhat.com [mailto:fedora-list-bounces@redhat.com] On Behalf Of Adam Hough Sent: Wednesday, October 25, 2006 10:34 AM To: For users of Fedora Core releases Subject: Re: Memory staying in cached status -- Possible Memory Leak
Have you ran a memtest86+ on the box?
On Wed, 2006-10-25 at 10:31 -0400, Kaplan, Andrew H. wrote:
Hi there --
I am running Fedora Core 5 that was hardened by Bastille Linux on a system
with
1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached
RAM
is going up. This results in the amount of free memory going down to where
there
is almost nothing left. The end result has been the system to periodically hanging, which forces me to reboot the server.
What can I do to correct this problem? Thanks.
Kaplan, Andrew H. wrote:
I ran a memtest86+ scan on the box, and there were no errors reported by application. At this point it would appear there is a resource hog that is causing this issue. What utility can I use to track the usage of the various programs on the system.
The top utility comes to mind, but what options would I use including the ability to output the results to a file?
Three things:
Do you have swap turned on? If so, how much is being used just before it crashes?
The free command should tell you this: if you want to script this, something like while true ; do free >> ~/free.log ; sleep 30 ; done should append the output of "free" to a logfile in your home directory until you press Ctrl-C.
Thirdly, top -b -d30 > ~/top.log ought to do you.
Hope this helps,
James.
I like to use a utility called nmon. (I know that there are other utilities but cannot think of them atm.) It can profile the resource usage of a machine but I do not remember if it will actually output the memory usage of the programs running. http://www-941.haw.ibm.com/collaboration/wiki/display/WikiPtype/nmon
http://www-941.haw.ibm.com/collaboration/wiki/download/attachments/437/nmon4...
To use top to output to a file. "top -b -n X (where X is how many times you want it to run)
/someplace/somefile"
A "top -b" will run until the it is stopped and will update every 3 seconds.
On Mon, 2006-10-30 at 12:00 -0500, Kaplan, Andrew H. wrote:
Hi there --
I ran a memtest86+ scan on the box, and there were no errors reported by application. At this point it would appear there is a resource hog that is causing this issue. What utility can I use to track the usage of the various programs on the system.
The top utility comes to mind, but what options would I use including the ability to output the results to a file?
-----Original Message----- From: fedora-list-bounces@redhat.com [mailto:fedora-list-bounces@redhat.com] On Behalf Of Adam Hough Sent: Wednesday, October 25, 2006 10:34 AM To: For users of Fedora Core releases Subject: Re: Memory staying in cached status -- Possible Memory Leak
Have you ran a memtest86+ on the box?
On Wed, 2006-10-25 at 10:31 -0400, Kaplan, Andrew H. wrote:
Hi there --
I am running Fedora Core 5 that was hardened by Bastille Linux on a system
with
1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached
RAM
is going up. This results in the amount of free memory going down to where
there
is almost nothing left. The end result has been the system to periodically hanging, which forces me to reboot the server.
What can I do to correct this problem? Thanks.
-- Adam Hough High Performance Computing Computing Services Center 200 225-578-7202 fax: 225-578-6400 ahough@lsu.edu
-- fedora-list mailing list fedora-list@redhat.com To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
<quote who="Kaplan, Andrew H.">
Hi there --
I ran a memtest86+ scan on the box, and there were no errors reported by application. At this point it would appear there is a resource hog that is causing this issue. What utility can I use to track the usage of the various programs on the system.
The top utility comes to mind, but what options would I use including the ability to output the results to a file?
vmstat with it's sadc (data collector) and sar (reporter). I'm not sure if you can get a per process listing but it will save your memory, swap and CPU usage to a file at set intervals. Here is a page with some good information:
http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/admin-primer/s1-resour...
On Wed, Oct 25, 2006 at 10:31:23AM -0400, Kaplan, Andrew H. wrote:
I am running Fedora Core 5 that was hardened by Bastille Linux on a system with 1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached RAM is going up. This results in the amount of free memory going down to where there is almost nothing left.
That's normal behaviour. The OS uses unused RAM to cache disk access. When it needs to use the RAM for something "proper", it just reclaims it.
As long as the -/+ buffers/cache line shows lots free, you're ok.
The end result has been the system to periodically hanging, which forces me to reboot the server.
Your fault most likely lies elsewhere.
On Oct 25 Dave Mitchell did spake thusly:
On Wed, Oct 25, 2006 at 10:31:23AM -0400, Kaplan, Andrew H. wrote:
I am running Fedora Core 5 that was hardened by Bastille Linux on a system with 1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.
I have noticed over time, via the free -m command, that the amount of cached RAM is going up. This results in the amount of free memory going down to where there is almost nothing left.
That's normal behaviour. The OS uses unused RAM to cache disk access. When it needs to use the RAM for something "proper", it just reclaims it.
As long as the -/+ buffers/cache line shows lots free, you're ok.
The end result has been the system to periodically hanging, which forces me to reboot the server.
Your fault most likely lies elsewhere.
Somebody told me yesterday that the "free" column should be kept as close to 0 as possible by the linux kernel. Is this true? Coz mine ain't...
On Thu, Oct 26, 2006 at 11:05:06AM +0100, Scott van Looy wrote:
Somebody told me yesterday that the "free" column should be kept as close to 0 as possible by the linux kernel. Is this true? Coz mine ain't...
On reboot, [Mem: free] and [-/+ buffers/cache: free] will both be large. As apps claim memory, both will fall. As apps access files and more data becomes cached, [Mem: free] falls. If the apps don't do much disk I/O, then it wont reach near zero. If and when it reaches near zero, it will remain that way until reboot.
Today Dave Mitchell did spake thusly:
On Thu, Oct 26, 2006 at 11:05:06AM +0100, Scott van Looy wrote:
Somebody told me yesterday that the "free" column should be kept as close to 0 as possible by the linux kernel. Is this true? Coz mine ain't...
On reboot, [Mem: free] and [-/+ buffers/cache: free] will both be large. As apps claim memory, both will fall. As apps access files and more data becomes cached, [Mem: free] falls. If the apps don't do much disk I/O, then it wont reach near zero. If and when it reaches near zero, it will remain that way until reboot.
That was my understanding too. That's the last time I talk to an ubuntu engineer...giggle
Dave Mitchell wrote:
On reboot, [Mem: free] and [-/+ buffers/cache: free] will both be large. As apps claim memory, both will fall. As apps access files and more data becomes cached, [Mem: free] falls. If the apps don't do much disk I/O, then it wont reach near zero. If and when it reaches near zero, it will remain that way until reboot.
There is one other wrinkle...
Memory can be released for various reasons, in which case it does go back into the "free" pile. For example, if a file is deleted, then there's no point keeping its contents in cache. If a program exits, then the memory it used can be reused.
James.