Topic: resize the swap-partition

[Rien]

Hi,

Because I dit a memory upgrade from 256MB to 512MB, I want to adjust the swap space.

Can I do that safely with partitionmagic?

Thanks,

Rien

[grand-pa]

Why do you want to adjust the swap space ?
There is no need to do so just because you've added some RAM to you server. Or, is there any other reason ?

[Rien]

Hi,

I understood that the swap-space must be equal or bigger than the size of RAM.

That's what I read in the RedHat manual.

Rien

[grand-pa]

No, the swap space must be equal or bigger than what you need.

So, the good question is : do you really need to have 1GB of memory (512 Mo of physical RAM + 512 Mo of Swap) ?

I guess no, so you probably don't need to increase your swap space.
But if the answer is [YES], then you have to create a new swap partition on an other disk (by default, after the installation, there is no space available on the primary hard drive).

[Rien]

Hi grand-pa,

Good question. PHPsysinfo reports a memory usage of 85%- 99% and a swap usage of 32%.

I use SME 6.0 final in "server and gateway mode" (webserver, fileserver, mailserver, the whole thing).
on a Dell Dimension 4100 with an Intel P3 866Mhz cpu.

So, what's a normal memory usage?

Rien

[grand-pa]

A "normal" memory usage value reported by phpSysInfo 2.1 is 85%-100%. With previous versions of phpSysInfo, you could have 30Mo-60Mo of physical memory used on an SME system.

In fact, since the v2.1, this value is not calculated as it was in previous versions : it now includes buffers and cached memory in the reported values.

If, as me, you prefer to see only memory used by the processes, you can modify the line 338 of the file phpSysInfo_directory/includes/os/class.Linux.inc.php :

Code: [Select]

$results['ram']['t_used']  = $results['ram']['used'];
  must be replaced by
$results['ram']['t_used']  = $results['ram']['used'] - $results['ram']['cached'] - $results['ram']['buffers'];

A swap usage of 32% (of the default 256Mo swap space) may be normal, depending on the number of processes running on your system. For a "whole thing", it looks like a good value for me.

[Rien]

Thanks,

That's a big difference. Now is an usage of 10%. Is the rest really free for other processes?

Rien

[grand-pa]

Yes and no, the rest is used by buffers and cache but most of it can be allocated to any new process.

My english isn't enough good to explain that but you can follow this link.

[Rien]

Thanks, I think I understand how it works now.

Rien