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Old 05-14-2006, 02:46 AM   #1
alpha754293
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Registered: May 2006
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Quote:
Originally Posted by Athlon_Jedi
OK the reason for the way linux is "using" so much ram is that unlike the way windows manages memory(by putting it into a wait state untill its used, hence bsod and similar problems) linux ACTIVELY manages the memory in a particular system meaning it puts a flag into the first byte of every MEGABYTE of memory in the system that tells the kernel what is in "use" and what is not. The kernel then in turn knows how much memory is available for things like disk cache, apps and so forth so it doesnt have to change the state of memory from a wait state to an active(i.e. useable) state. because it is ALL active all the time. This is why apps and such run better under linux because they dont have to wait on the memory they require to"wake up". the kernal can place data into memory DIRECTLY. its also why the unix version of pre-emtive multitasking is more stable than the MS version.
Hi there. I know that this is an old thread, but I just completed my first Linux install.

My system also, currently has 1 GB of RAM, of which, 998 MB of it is being reported as being used in RedHat 9.

(This is right after a fresh install, BTW).

System specifications are as follows:

AMD Duron 1.8 GHz
MSI K7N2-Delta2
2x Crucial 256 MB PC2100 DDR SDRAM
Crucial 512 MB PC2100 DDR SDRAM
4x Hitachi 250 GB 7.2krpm ATA/100 (on RAID5)
Promise SuperTrak SX6000 w/ 128 MB
Netgear GA311 10/100/1000 NIC (RTL8169)
Powercolor Radeon 7000 32 MB

OS and data reside on the same RAID5 array.

I had programs lock up on me because it was waiting for a kernel response and timed out, (can happen repeatedly).

So, I don't see how this could be a better method.

From my experiences with SVR4-based UNIXes; I know that they don't load everything into the RAM (either flagged or otherwise) because that is, by in large, impractical.
 
Old 05-14-2006, 03:43 PM   #2
Mara
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Registered: Feb 2002
Location: Grenoble
Distribution: Debian
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Moderator note:
The post above was moved from http://www.linuxquestions.org/questi...d.php?p=216358 because of two reasons: the orginal threads is very old, and, what's more important, I have a stron reasons to think that the problem mentioned in the thread above is completely different from the one discussed in the thread it was orginally posted.


alpha754293, the problem you have is with the kernel resonses (the timeouts you have mentioned). If they're not requesting much more RAM than the machine has, the problem is not in the amount used. How do stats look like? The most interesting is the result of 'free'. What does it show? And also, why do you think it's a memory access problem?
 
Old 05-16-2006, 10:41 AM   #3
alpha754293
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Registered: May 2006
Posts: 7

Original Poster
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Quote:
Originally Posted by Mara
Moderator note:
The post above was moved from http://www.linuxquestions.org/questi...d.php?p=216358 because of two reasons: the orginal threads is very old, and, what's more important, I have a stron reasons to think that the problem mentioned in the thread above is completely different from the one discussed in the thread it was orginally posted.


alpha754293, the problem you have is with the kernel resonses (the timeouts you have mentioned). If they're not requesting much more RAM than the machine has, the problem is not in the amount used. How do stats look like? The most interesting is the result of 'free'. What does it show? And also, why do you think it's a memory access problem?
Well, right now the system is reporting 1007 MB (according to the system monitor) in RH9, of which, 997-998 MB of it is used (representing 99% of all available memory).

I did a full install (i.e. install everything in the options in RH9), about 4.8 GB in all.

I still haven't been able to come up with the same number that is being reported as being used checking the process and thread memory usages, which begs the question: "what gives?" (hence the relevance to the old thread.) I also figured that rather than starting a new thread about the same question/issue, and cross-referencing it, that I just posted it where I thought it belong.

No matter what I do with the system, it pretty much around that level.

I have frozen the package manager numerous times and also crashed nautilus, gnome, mozilla.

I know that this isn't a faulty system (CPU, memory, mobo) because prior to the server migration, it was running Solaris 10 3/05 stable on the same platform. (I switched because I wanted HW ATA RAID5 support, and the Promise SX6000 is not supported there.)

Free mem is around 10 MB. (I do not know how to check it via CLI.)

Based on my experiences with AIX, Solaris, and HP-UX, this is highly unusual/abnormal.

I also do not agree with the person that responded saying that the way how Linux is managing the memory is better. If the idea is that it is going to index it; then I would expect much better response times than what I have been getting on the system.

If there is significant activity on the array (which I am also not accustomed to the lack of being able to monitor the status of the drives); it usually takes a while for the system to kick in, even if it's something as simple as 'ifconfig -a'.

From my experiences with Solaris 10, I can push/pull 17.5 MB/s across the system and the system would only be using about 100 MB or so of RAM, and wouldn't have issues processing other commands.

Any ideas?
 
  


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