Questions tagged [memory]
Synonym for: RAM - Acronym for: Random Access Memory, a type of computer data storage.
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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 ...
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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:...
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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 ...
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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, ...
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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't ...
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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).
...
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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. ...
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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 ...
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3
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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 ...
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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 ...
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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. ...
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What does Virtual memory size in top mean?
I am running top to monitor my server performance and 2 of my java processes show virtual memory of up to 800MB-1GB. Is that a bad thing?
What does virtual memory mean?
And oh btw, I have swap of ...
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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, ...
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What is ECC ram and why is it better?
I've seen a dicussion about ECC ram use on servers. Why is it better?
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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 ...
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Caching/preloading files on Linux into RAM
I have a rather old server that has 4GB of RAM and it is pretty much serving the same files all day, but it is doing so from the hard drive while 3GBs of RAM are "free".
Anyone who has ever tried ...
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How does vm.overcommit_memory work?
When I use the default settings:
vm.overcommit_memory = 0
vm.overcommit_ratio = 50
I can read these values from /proc/meminfo file:
CommitLimit: 2609604 kB
Committed_AS: 1579976 kB
But when ...
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"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 ...
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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 ...
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Any benefit or detriment from removing a pagefile on an 8 GB RAM machine?
I'm running Windows 7 on a dual core, x64 AMD with 8 GB RAM.
Do I even need a page file?
Will removing it help or hurt performance?
Would it make a difference if this is a server or a desktop?
...
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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?
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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-...
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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 ...
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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 ...
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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 ...
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Page allocation failure - Am I running out of memory?
Lately, I've noticed 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
I'd like to know:
What exactly ...
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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....
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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?
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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=...
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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 ...
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Windows Server 2008 x64, Large File Transfers, and Memory Usage
I'm following up on this:
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 server, Xeon 5405, with 14GB memory, and ...
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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 ...
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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?)
open
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10
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Linux: how to explicitly unswap everything possible?
I've launched something that took lots of memory and now everything lags a lot.
I guess all applications' memory has gone to swap in order to free some space for the memory-intensive process, and now ...
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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 Finegrained performance reporting on svchost.exe
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Get a history of CPU/memory usage
Is there someway to record Task Managers info about CPU and memory usage to examine later? Or an equivalent tool?
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How do I get notified of ECC errors in Linux?
How do I get notified, when a Linux machine equipped with ECC memory recognizes a memory failure? I'm interested in both correctable and uncorrectable errors.
if a message is written to dmesg/the ...
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Unusually high dentry cache usage
Problem
A CentOS machine with kernel 2.6.32 and 128 GB physical RAM ran into trouble a few days ago. The responsible system administrator tells me that the PHP-FPM application was not responding to ...
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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?
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How is memory usage reported in Linux?
Using ps, I can see the size, the vsize (same as top's VIRT?), and the rss (same as top's RES?). (One more I see in top is SHR.)
Could someone summarize for me what these different fields mean?
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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 ...
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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
...
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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 ...
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MySQL (MariaDB) crashes frequently
I recently migrated an old server running MySQL to a new VPS running MariaDB 5.5. I don't have too much running on the server (just a few PHP sites) and free memory seems to be OK, but the DB keeps ...
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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 ...
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