Web Hosting Talk : Web Hosting Main Forums : Dedicated Server : Free Memory - CentOS 4.3

[JdS]

Hello,

Recently, I picked up one of servertweak.com's offer of a dedicated server. 1 GB RAM was offered (in case you skip looking at the thread).

Running the `top` command, I find this:

Mem:    970780k total,   234876k used,   735904k free,      572k buffers
Swap:  1020116k total,   139168k used,   880948k free,    13668k cached

My 2 questions:

1. Is it possible that the RAM is actually 1 GB but is being reported at just 970,780 Kbytes?

2. I have never seen a Linux server with so much FREE memory -- 735,904 Kbytes. Swap memory is being used and grows over the course of the day, while the free memory remains steady at slightly over 700MB. Been like that for days now... What could be the cause of it and I will appreciate any suggestions.

I have asked my host these questions and they replied that:

1. It is 1 GB
2. It's not a problem (paraphrased).

More details can be found here: http://www.gidforums.com/t-9432.html

Thank you for reading.

[Alex]

Login via SSH, su to root, and type...

$ cat /proc/meminfo

What does the top line say?

[JdS]

The info you requested:

[jds@bella ~]$ cat /proc/meminfo
MemTotal:       970780 kB
MemFree:        778168 kB
Buffers:          1592 kB
Cached:          19772 kB
SwapCached:      20424 kB
Active:         168436 kB
Inactive:         5492 kB
HighTotal:       65472 kB
HighFree:         1080 kB
LowTotal:       905308 kB
LowFree:        777088 kB
SwapTotal:     1020116 kB
SwapFree:       938580 kB
Dirty:             132 kB
Writeback:           0 kB
Mapped:         160452 kB
Slab:            10088 kB
Committed_AS:   710308 kB
PageTables:       2364 kB
VmallocTotal:   106488 kB
VmallocUsed:      2128 kB
VmallocChunk:   104004 kB
HugePages_Total:     0
HugePages_Free:      0
Hugepagesize:     4096 kB

Thank you for replying.

[Alex]

Hmm, well it looks like you should have 1GB, but usually with 1GB of RAM you get more than 100000 kB displayed, not less.

You might check with your host about your SWAP settings, but other than that this is bizarre.

[JdS]

Trust me, I have tried repeatedly! You can tell that I am really desperate when I am driven to post here.

He even replied today:

I'm not sure what you're trying to say but ram is sold 128KB, 256KB, 512KB,
1GB, 2GB+. If you understand how ram is manufactured, no combination will
add up to 970780k. Just to make this clear, I installed 1GB of memory via a
1GB stick.

I'm sure other people on WHT will explain this to you as well...

emphasis mine

I swear, it's like pulling teeth.

[goolex]

i have 1gb installed in my server and this is result

root@web [~]# cat /proc/meminfo
MemTotal: 969756 kB

i am not 100% sure but i think rest of memory is used by AGP/PCI Address Space

[JdS]

But you see this guy doesn't even explain why there is a discrepancy in the first place. He keeps insisting that I am too stupid to simply accept what he says is true.

Do you also have over 700MB free memory when you run `top`? I am just curious now.

[Adam A Flynn]

I am in a similar boat. I've got 512 MB which reports around 460 MB. I was told the difference was used for swap (doesn't quite make sense to me, since swap by its nature is not using real memory, but I'm no guru). If this is the case, how would I tweak these settings? Swap has no business consuming 10% of my memory though, not when it's usually almost completely maxed out by mysql anyway.

Adam A Flynn

[Alex]

Oh, perhaps it is becuase you have one 1GB stick instead of two 512MB sticks. That would explain why the RAM is showing under 100,000 kB instead of a little bit over. Still, your close enough to 100,00 kB I wouldn't worry about having the full 1GB of RAM. I would be a bit worried, however, about the amount of swap usage, especially when there is so much RAM left to be used.

[tical]

The difference in the amount of physical RAM detected by the BIOS and the amount of RAM shown in Linux is usually the effect of shared graphics memory. The amount of shared memory in use is usually either 8, 16, 32 or 64MB. This applies to every system with onboard graphics RAM.

For reference purposes, we configure the BIOS of our systems for 16MB of graphics RAM, which would still report 100,012K in linux's "top" command.

[Adam A Flynn]

How do I insist that my server not try to use much RAM for graphics? If it's actually allocating what's probably 64 MB to graphics, when all the graphics processing that's needed is rendering some GD images from time to time, that's just silly and wasteful.

[tical]

Originally Posted by Adam A Flynn

How do I insist that my server not try to use much RAM for graphics? If it's actually allocating what's probably 64 MB to graphics, when all the graphics processing that's needed is rendering some GD images from time to time, that's just silly and wasteful.

Your box doesn't even use shared RAM to render graphics with GD.. this is purely for console graphics. You'll have to speak to your host about it, as the amount of shared RAM is a BIOS setting that you won't have access to.

[Adam A Flynn]

Okay. Is it possible that the memory is being used for swap space as the host said?

[tical]

It's not possible that the discrepancy in RAM size has anything to do with swapping.

[rumi]

I got 1GB of RAM 2 x 512MB DDR PC 3200

#cat /proc/meminfo
MemTotal: 1002812 kB
MemFree: 18008 kB
Buffers: 91800 kB
Cached: 456516 kB
SwapCached: 2096 kB
Active: 677528 kB
Inactive: 219960 kB
HighTotal: 98112 kB
HighFree: 160 kB
LowTotal: 904700 kB
LowFree: 17848 kB
SwapTotal: 2031608 kB
SwapFree: 2029348 kB
Dirty: 900 kB
Writeback: 0 kB
Mapped: 365808 kB
Slab: 78256 kB
CommitLimit: 2533012 kB
Committed_AS: 718724 kB
PageTables: 2300 kB
VmallocTotal: 114680 kB
VmallocUsed: 2824 kB
VmallocChunk: 111664 kB
HugePages_Total: 0
HugePages_Free: 0
Hugepagesize: 4096 kB