Synonym for: RAM - Acronym for: Random Access Memory, a type of computer data storage.

learn more… | top users | synonyms (1)

45
votes
5answers
23k views

How to understand the memory usage and load average in linux server

I am using a linux server which has 128GB of memory and 24 cores. I use top to see how much it is used. Its output is pasted at the end of the post. Here are two questions: (1) I see that each of the ...
99
votes
3answers
91k views

Meaning of the buffers/cache line in the output of free

Why does my server show total used free shared buffers cached Mem: 12286456 11715372 571084 0 81912 6545228 -/+ buffers/cache: 5088232 7198224 Swap:...
9
votes
5answers
24k views

Why does Red Hat Linux report less free memory on the system than is actually available?

I have a relatively small home Red Hat Linux server (about 8 GB RAM). I don't use it for much other than running some home grown apps to keep track of various things. The only real things running on ...
49
votes
2answers
4k views

vSphere education - What are the downsides of configuring VMs with *too* much RAM?

VMware memory management seems to be a tricky balancing act. With cluster RAM, Resource Pools, VMware's management techniques (TPS, ballooning, host swapping), in-guest RAM utilization, swapping, ...
64
votes
11answers
20k views

Why drop caches in Linux?

In our servers we have a habit of dropping caches at midnight. sync; echo 3 > /proc/sys/vm/drop_caches When I run the code it seems to free up lots of RAM, but do I really need to do that. Isn'...
20
votes
2answers
22k views

How to interpret output from Linux 'top' command?

Following a discussion made HERE about how PHP-FPM consuming memory, I just found a problem in reading the memory in top command. Here is a screenshot of my top just after restarting PHP-FPM. ...
15
votes
1answer
6k views

deleting linux cached ram [duplicate]

I have a webserver that has 8GB of ram and is running a pretty intensive php site (1 site) that does file manipulation, graphing, emailing, forums, you name it. The environment is far from static ...
54
votes
4answers
37k views

In Linux, what is the difference between “buffers” and “cache” reported by the free command?

This is an old question that I've seen from time to time. My understanding of it is rather limited (having read about the differences a long time ago, but the factoid(s) involved never really stuck). ...
28
votes
4answers
23k views

What is ECC ram and why is it better?

I've seen a dicussion about ECC ram use on servers. Why is it better?
10
votes
11answers
8k views

How big should the swap partition be?

for some years, I've read that it's a good idea to create a swap partition having the double space of my RAM. does it still apply today? or this isn't needed anymore? I have a server with 8 GiB of ...
4
votes
1answer
5k views

How much free memory should I have on my webserver? [duplicate]

I have a webserver that's currently hosting two Wordpress sites and some java-based collaboration software. The server has 2G of memory and is currently using about 1.8G of the available memory. ...
8
votes
2answers
13k views

Running out of memory running fsck on large filesystems

I look after an old Debian linux box (running etch) with only 512 MB of RAM, but a lot of external storage attached. One ext3 filesystem is 2.7 TB in size, and fsck can't check it, because it runs ...
6
votes
2answers
2k views

SQL Server memory constantly going up, from 1GB RAM used to 7GB in a week

I have a ~45GB database that increases rapidly (~1GB every week). So it's doing a lot of inserts; the web app doesn't have many users so reads are low right now. But I'm noticing that the RAM sql ...
9
votes
1answer
6k views

“Unballooning” RAM that's been ballooned by VMware

Given the constrained RAM situation described in this question, what is the cleanest method (manual or programmatically) to: Identify VMware virtual machines whose RAM has been reclaimed by the ...
194
votes
13answers
72k views

Any benefit or detriment from removing a pagefile on an 8GB RAM machine?

I'm running Windows 7 on a dual core, x64 AMD with 8GB RAM. Do I even need a pagefile? Will removing it help or hurt performance? Would it make a difference if this is a server or a desktop? Does ...
35
votes
9answers
36k views

How to reduce memory usage on a Unix webserver

I'm currently using a Joyent Accelerator to host my webapps, and it's working fine, however I need to reduce costs so I'm downgrading my current plan and that imposes some new memory limits (256M rss, ...
24
votes
6answers
60k views

Dump a linux process's memory to file

Is it possible to dump the current memory allocated for a process (by PID) to a file? Or read it somehow?
17
votes
4answers
19k views

How can I determine the cause of an apparent memory leak in my Apache/PHP based web app?

About once a week, but sometimes even a couple of times a day after running fine for days, my EC2 instances become unresponsive. Munin's memory graphs tell a pretty straightforward story: memory ...
33
votes
3answers
22k views

Turn off the Linux OOM killer by default?

The OOM killer on Linux wreaks havoc with various applications every so often, and it appears that not much is really done on the kernel development side to improve this. Would it not be better, as a ...
14
votes
13answers
13k views

Simple tool to graph memory usage?

Is there a script that will show memory usage as a graph, for example as a pie-chart, with each process being being a separate slice? I'm not looking for something like Munin to graph memory usage ...
29
votes
7answers
3k views

Is it necessary to burn-in RAM for server-class hardware?

Considering the fact that many server-class systems are equipped with ECC RAM, is it necessary or useful to burn-in the memory DIMMs prior to their deployment? I've encountered an environment where ...
17
votes
3answers
35k views

page allocation failure - am I running out of memory?

Lately I've noticing entries like this one in the kern.log of one of my servers: Feb 16 00:24:05 aramis kernel: swapper: page allocation failure. order:0, mode:0x20 This is what I'd like to know: ...
8
votes
5answers
15k views

32-bit Windows Server address > 4GB RAM - How?

This is news to me. I was always under the impression that 32-bit OS could only address 2^32 i.e. 4GB of RAM. Period. But what's this - http://www.crucial.com/uk/kb/answer.aspx?qid=3743&click=...
5
votes
4answers
705 views

Memory Usage in LINUX [duplicate]

I have a debian system. It has 8GB memory. When I do top it shows 7.9 GB memory used and rest free. I add up the memory usage of all the programs running from top and they hardly sum up to around 50 ...
5
votes
3answers
11k views

Windows Server 2008 x64, Large File Transfers, and Memory Usage

I'm following up on this: http://serverfault.com/questions/37605/copying-large-file-to-remote-server-causes-it-to-run-out-of-physical-memory But figured I'd post this separately. I have a 64-bit ...
4
votes
6answers
2k views

linux eats all memory, seems like it is not for specific application [duplicate]

The system is not overloaded and there is no huge process that eats memory (RAM) but still it has only 20-40 MB free. Who is taking RAM and should I avoid it? (how?)
3
votes
1answer
15k views

SBS 2011 - Is Store.exe High Memory Usage Normal?

We have a SBS 2011 server with 16GB memory that runs Exchange, WSUS and File Sharing for approx 20 users. The server also gives 2GB memory to a virtual machine running in Hyper-V so 14GB left for the ...
9
votes
2answers
72k views

What is the difference between RDIMM vs UDIMM

I don't quite understand the differences between the two besides the obvious price differences. What does each offer over the other?
4
votes
1answer
48k views

HP DL160 G6 memory PC3-10600R vs PC3-10600E

I am using a HP DL 160 G6 server that according to specs takes PC3 Registered or Unbuffered. When I combine the two types of memory below the system will not POST. When I use just the first type of ...
33
votes
7answers
63k views

How to find memory usage of individual Windows services?

Task Manager shows the overall memory usage of svchost.exe. Is there a way to view the memory usage of individual services? Note this is similar to http://serverfault.com/questions/2786/finegrain-...
19
votes
4answers
88k views

DIMMs: Single vs. Double vs. Quad Rank

What difference does the 'Rank' of DIMMs make to server memory? For example, when looking at server configurations I see the following being offered for the same server: 2GB (1x2GB) Single Rank PC3-...
12
votes
1answer
10k views

Linux not freeing large disk cache when memory demand goes up

Running Ubuntu on a 2.6.31-302 x86-64 kernel. The overall problem is that I have memory in the 'cached' category that keeps on going up and will not be freed or used even when our application needs it....
12
votes
3answers
7k views

Non-ECC memory with ZFS: a stupid idea?

I have a new server and am planning to upgrade the paltry 2 GB of memory to the maximum of 16 GB. (Theoretically 8 GB is the limit, but empirically 16 GB has been shown to work.) Some guides advise ...
27
votes
7answers
33k views

Windows Server 2008 R2 Metafile RAM Usage

I have a server which runs Windows Server 2008 R2 x64 with 4GB of RAM which hosts around 2-3 million files, the majority of which are image files. Over a course of a week, I have noticed that ...
14
votes
6answers
52k views

Weird memory usage in Windows Server 2008 R2

I hope someone can help. We've got a Windows Server 2008 R2 machine with 16GB of RAM that keeps getting all its available memory eaten by something. Nothing in Task Manager or Resource Monitor reveals ...
14
votes
8answers
11k views

Would you use ECC RAM in a workstation?

Is ECC RAM recommended for use in workstations, or is it something that only gets used in servers? If non-ECC RAM works in PCs, why would we need ECC RAM at all?
1
vote
3answers
4k views

How to find out if my Windows Server 2003 needs more memory?

What's the best way to find out if my server needs more memory? I suppose I should use Perfmon, but which counters? Thanks.
14
votes
7answers
16k views

After upgrading to 2008 R2 Enterprise and installing more RAM, Windows can only see 4.00 GB

(I have also posted this on technet but I'm running out of ideas) I've upgraded from Windows Server 2008 R2 Standard to Enterprise in order to make use of more RAM. The server previously had 32GB of ...
13
votes
5answers
11k views

SQL Server 2005: There is insufficient system memory to run this query

One of our SQL Servers, which has been running stable for quite some time (years), has recently been throwing insufficient memory errors. From the Application Event Log, we see: Event ID: 701 ...
7
votes
4answers
3k views

When is swap moved back to physical memory?

When is swap moved back to physical memory in Linux? Is it only on demand, ie. when it's needed? Or is swap slowly transfered to physical memory when the computer is not on high load?
6
votes
3answers
5k views

e2fsck on large filesystem fails with Error : Memory Allocation Failed

I'm trying to use e2fsck on a large raid array that is 2TB large and uses GPT for partitioning (because of size). There is only 1GB of ram installed on the system and I do not have the ability to add ...
6
votes
5answers
5k views

Free / Cached / Available memory on Linux

I have read that linux uses free memory for caching, to make system faster. However, both Nagios and Paessler PRTG monitoring system show me that my memory usage is critical. I could change Nagios ...
4
votes
1answer
6k views

CPU/RAM upgrade for HP Proliant ML350 G5

I have an HP ML350 G5 server with a single Intel 5130 dual core Xeon installed. Is it possible to upgrade it to a dual processor system? I've looked at the quickspecs and spent a couple of hours ...
3
votes
2answers
1k views

Unexplained cache RAM drops on Linux machine

I run a CentOS 5.7 64 machine with 24gb ram and running kernel 2.6.18-274.12.1.el5. This machine runs only Nginx, php-fpm and Xcache as extra applications. Since about 3 weeks my memory behavior on ...
2
votes
2answers
343 views

free reports bogus amount of swap used

The swap used reported by free is very high. [root@rhel6 ~]# free -m total used free shared buffers cached Mem: 9892 9537 354 0 ...
1
vote
3answers
9k views

How to determine what type of RAM I need?

I have to upgrade the RAM on 8 different desktop PCs - each of them with varying specs, different ages, different manufacturers, different motherboards, etc. I'm pretty sure they don't all use the ...
5
votes
4answers
1k views

Why is my server using so much memory?

I haven't even set up my website on my dedicated server so I'm the only one using it at the moment. And yet this is what I see in my sys info: Full Size I just got a bunch of security softwares ...
5
votes
1answer
3k views

Total RAM % from perfmon Windows Server 2008 R2

I am trying to find a good way to get available RAM percentage from perfmon. I can get Available Mbytes but I can't find any way to get the total installed memory on the server or what is in use via ...
4
votes
2answers
493 views

Are there any disadvantages to unusual RAM amounts for virtual machines?

This is going to seem like a silly question, but many many years ago I somehow got it into my head, perhaps from reading an article or speaking to people 'in the know' that a computer should not be ...
3
votes
7answers
9k views

Copying large file to remote server causes it to run out of physical memory

I have a strange issue that appears to have started recently. When I copy a large file (Approx 6GB) from my laptop to one of our older fileservers the server runs out of memory after a few seconds. ...