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Old 06-01-2007, 05:00 PM   #16
rsmccain
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Quote:
Originally Posted by Tinkster
It wouldn't be something silly like a kernel parameter that tells
the machine not to use more than that piddly amount? Check your
grub/lilo config. It certainly doesn't look right, and no, it's
not "Linux' great memory management at work".


Cheers,
Tink

Tink,

That's what I was thinking. Somewhere I'm telling Linux not to go above a certain amount of physical memory. I just can't find where it might be set. I'll check my kernel parms.
 
Old 06-01-2007, 05:07 PM   #17
rsmccain
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Quote:
Originally Posted by DirkDiggler
I stand corrected, if that site is correct then that is weird. What does 'top' yield for you? Unfortunately, I can't do anything with my system as I am at work right now. We don't have Linux here.

Regards,

Brandon
Dirk,

top shows the same thing: Around 350 megs of memory in use. No process is using more than a few megs of memory. CPU is hovering around 1-5% usage.
 
Old 06-01-2007, 05:15 PM   #18
syg00
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Quote:
Originally Posted by rsmccain
Because Linux always uses as much memory as possible.
Rubbish. It tries to effectively use the memory you have.
The article you quoted is old, and generalizes based on 90 Meg of memory. Less than 10% of what you have.
You have shown no evidence that you have a workload that requires more memory than it is using.
 
Old 06-01-2007, 05:18 PM   #19
DirkDiggler
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How long has your computer been idle for? For kicks and giggles, try restarting your computer and see what happens.

REgards,

Brandon
 
Old 06-01-2007, 05:19 PM   #20
rsmccain
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Quote:
Originally Posted by syg00
Rubbish. It tries to effectively use the memory you have.
The article you quoted is old, and generalizes based on 90 Meg of memory. Less than 10% of what you have.
You have shown no evidence that you have a workload that requires more memory than it is using.
Effectivley sounds better.

Anyways, I'm not lying about the "used" column should always be close to the amount of the "total" column.

Try it on any box you have whether its idle or busy.
 
Old 06-01-2007, 05:20 PM   #21
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Syg,

I know you weren't supporting my cause, but Rs made me think I was going crazy. Thanks for reaffirming what I thought I knew.

Regards,

Brandon
 
Old 06-01-2007, 05:20 PM   #22
rsmccain
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Quote:
Originally Posted by DirkDiggler
How long has your computer been idle for? For kicks and giggles, try restarting your computer and see what happens.

REgards,

Brandon
When it reboots it maxes out the CPU running udevinfo and hwscan. I assume this is because it is only allocating ~300 megs of RAM.

Currently its been idle for 5 hours or so, but I've rebooted it numerous times, put heavy loads on the server and free -m still shows the same thing.
 
Old 06-01-2007, 05:21 PM   #23
rsmccain
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Originally Posted by DirkDiggler
Syg,

I know you weren't supporting my cause, but Rs made me think I was going crazy. Thanks for reaffirming what I thought I knew.

Regards,

Brandon
no, you're going crazy.

google for: linux memory "free -m"
 
Old 06-01-2007, 05:27 PM   #24
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lol. I understand the command, but I didn't think Linux would cache nearly 700MB of RAM. But if there isn't a need to do, why do so? That's my thinking behind. Call me crazy, you already have. lol.

regards,

Brandon
 
Old 06-01-2007, 05:32 PM   #25
Tinkster
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Quote:
Originally Posted by DirkDiggler
lol. I understand the command, but I didn't think Linux would cache nearly 700MB of RAM. But if there isn't a need to do, why do so? That's my thinking behind. Call me crazy, you already have. lol.

regards,

Brandon
Because it can and because it makes sense. rsmccain is perfectly
right in saying that the "used" should be next to same as "total",
certainly is on any Linux machine I've ever used or had my hands
on.

RAM for buffers/caching is the best thing next to super
expensive SCSI and solid-state to boost performance, to
leave it "unused" makes no sense, and is a very un-linuxy
thing to do ...

My notebook:
Code:
$ free -m
             total       used       free     shared    buffers     cached
Mem:          1002        907         94          0         47        529
-/+ buffers/cache:        331        670
Swap:          972          0        972
My server:
Code:
# free -m
             total       used       free     shared    buffers     cached
Mem:           251        246          4          0         92         48
-/+ buffers/cache:        105        145
Swap:          964        124        840
My wifes workstation:
Code:
$ free -m
             total       used       free     shared    buffers     cached
Mem:           995        937         58          0        110        451
-/+ buffers/cache:        376        619
Swap:          815         18        797

With a Gig of RAM used memory of 300 is just wrong, no matter
how long the machine has been running for.



Cheers,
Tink

Last edited by Tinkster; 06-01-2007 at 05:34 PM.
 
Old 06-01-2007, 05:36 PM   #26
DirkDiggler
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Ok, I'm convinced. I get it now.

Thanks,

Brandon
 
Old 06-01-2007, 05:41 PM   #27
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Nope. If you don't have anything chewing up I/O, the cache won't grow, and the usage will look low.
My test server at work has 4 Gig - usually sits at about that mark. I ensure I start the services I need when I need them - and that includes updatedb.
No I/O means next to no cache usage.

Should be easy enough to drive the numbers up - unnecessarily in my opinion. Fire off a decent sized database backup, and start updatedb in competition.

Last edited by syg00; 06-01-2007 at 05:42 PM.
 
Old 06-01-2007, 05:51 PM   #28
rsmccain
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Quote:
Originally Posted by syg00
Nope. If you don't have anything chewing up I/O, the cache won't grow, and the usage will look low.
My test server at work has 4 Gig - usually sits at about that mark. I ensure I start the services I need when I need them - and that includes updatedb.
No I/O means next to no cache usage.

Should be easy enough to drive the numbers up - unnecessarily in my opinion. Fire off a decent sized database backup, and start updatedb in competition.

when the system is booting up and udevinfo and hwscan are maxxing out the CPU at 100% the mem used is still between 200-350.
 
Old 06-01-2007, 05:56 PM   #29
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Quote:
Originally Posted by syg00
Nope. If you don't have anything chewing up I/O, the cache won't grow, and the usage will look low.
My test server at work has 4 Gig - usually sits at about that mark. I ensure I start the services I need when I need them - and that includes updatedb.
No I/O means next to no cache usage.

Should be easy enough to drive the numbers up - unnecessarily in my opinion. Fire off a decent sized database backup, and start updatedb in competition.
Humour me and post the output of free -m




Cheers,
Tink
 
Old 06-01-2007, 07:43 PM   #30
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Hey,

I made it home and used the 'free -m' command. My total is 756, used is 317 (thats with klotski running, a game), cached is 133. I started up GIMP, total is 756, used 355, cached is 154. Left klotski gimp open, opened up Open Office word processor and: total 756, used 472, cached 253. So, in my case, it doesn't cache more unless more stuff is opened. I'm running a fresh install of Fedora 7, in case you were wondering.

Regards,

Brandon

Last edited by DirkDiggler; 06-01-2007 at 07:48 PM.
 
  


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