Huge lack of Memory (RAM)

cyPHunk

Verified User
Joined
Aug 25, 2006
Messages
15
Hi Guys,

I have noticed that recently (last 3 months) my DA box has had less and less available RAM. So I decided that it was time to upgrade and transfer to a new and beefier server... which I did today.

Old Server: 1 x Xeon 5140, 4GB RAM, 2 x 250GB HDDs running CentOS 5 32bit
New Server: 2 x Xeon 3460, 8GB RAM, 2 x 250GB HDDs running CentOS 5 64bit

Have a look at top's results below... which are confusing me like hell!

New Server:
top - 12:35:25 up 18:50, 1 user, load average: 1.80, 1.47, 0.77
Tasks: 229 total, 1 running, 228 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 1.3%sy, 1.7%ni, 73.9%id, 22.4%wa, 0.0%hi, 0.7%si, 0.0%st
Mem: 8166584k total, 8119736k used, 46848k free, 49312k buffers
Swap: 1052248k total, 152k used, 1052096k free, 7696808k cached


Old Server:
top - 12:35:41 up 22:38, 1 user, load average: 0.05, 0.08, 0.08
Tasks: 227 total, 1 running, 226 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.0%sy, 0.0%ni, 99.8%id, 0.2%wa, 0.0%hi, 0.1%si, 0.0%st
Mem: 4149608k total, 3983348k used, 166260k free, 48672k buffers
Swap: 2096472k total, 100k used, 2096372k free, 3673648k cached

I am too much of a noob to tell where the Ram is going. All I see is one hell of a lot of IMAP, POP3, Apache, DirectAdmin, MySQL and Named Processes and Children.

My worry is that I have just upgraded to 8GB of RAM and I have NOTHING more available to me (almost)

Please help guys.

Chris
 
reloaded the server. Ram usage is now here:

top - 15:19:47 up 9 min, 1 user, load average: 0.03, 0.17, 0.10
Tasks: 228 total, 1 running, 227 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 8166544k total, 339020k used, 7827524k free, 16188k buffers
Swap: 2096472k total, 0k used, 2096472k free, 191376k cached

I have reloaded with RHEL5 64bit and have provisioned DirectAdmin and then rebooted. Sitting watching everything. RAM usage and buffer usage is low low low.

So the only thing that I can assume is that something that is running on the old server starts running after restoring/transferring data from existing server to the new one.

Pretty much nothing I can do now but try and find the cause?
Thanks for all of the input anyway.

Chris
 
Learn how Linux manages RAM. Linux will always show close to 100% usage of RAM. That is what you want. If it shows any RAM at all available then you have RAM that is just being wasted.

What you want to look at is SWAP. If your server is not swaping much then there is no reason to upgrade RAM.

Looks like you wasted your money upgrading.
 
Yeah... would appear so ;)
Unnecessary panic in the most paronoid form.

I needed to move the server into a Data Centre closer to us anyway, upgrade came in at a few dollars more than what we were paying before (like $20) and we ended up with so much more. So it was perhaps not too much of a waste.

I am certainly always learning none the less and thankful to all Forum members that are able to comment and provide information on my ignorance.

Strange thing on the CPU in the new server. It's a Quad Core X3460 which is reading 8 cores? The last server was also Quad Core but showed 4 cores as expected. Does thing have anything to do with the new Intel CPUs or is it a 32bit vs 64bit thing (i dont expect the latter since I understand the different bits are memory related only)

Thanks for your reply though Floyd. After re-installing OS and then installing DA... memory was almost showing as "used" again. When I started reading and understanding "memory usage in Linux" I began to become happier about what I was seeing.

I've "never" seen any swapping, so presumably my servers have always been sufficient.

Perhaps the server is over kill. We only have 60 accounts, 110 domains, 2000 mail users and some additional processess running that aren't too CPU/Memory intensive. Rather have something that is over kill than something that would end up being too small in a couple of years.

Chris
 
Somebody recently told me that it will show 8 if hyperthreading is turned on in the bios. I think its hyperthreading. It was something like that.
 
That's what I thought... stupid to report it as 8 cores though! But hey, I am no hardware manufacturer or vendor and I have taken on a business role in the company for the last 5 years so I have completely lost touch with technology.

Still, speaking as a noob business manager, sure does look prettier than 4 cores (doh!)
 
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