It is an extension of memory address space which is logically appended to the physical memory of a computer by the Memory Management Unit (MMU) of its processor. It is normally realized in operating systems by utilizing free disk space to implement such memory extension and may also be referred to ...

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1answer
26 views

Is there a way to check if my Virtual Memory Paging is “System Managed”

For one of our applications, we need to configure virtual memory on a Windows Machine to be system Managed. This can be done manually under System Properties -> Performance (Settings...) -> ...
1
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1answer
1k views

Proxmox - Assign more memory to KVM VM

Is it possible to assign more memory to a KVM virtual machine without restarting it? I changed the memory size of a VM using the Proxmox web interface, but can't see that increase in the guest.
0
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0answers
62 views

System process: high virtual memory usage

Azure virtual machine (3,5 Gb) with Server2012 running 2 IIS8 sites. At some time after reboot, System (pid 4) Private Virtual Memory reaches limit (15 Gb) with 2004 event: Windows successfully ...
44
votes
17answers
35k views

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 ...
3
votes
2answers
966 views

How can I keep important VMs in memory without disabling swap?

VM Host -> Xenon E5-2440 w/ 48G mem... Everything runs CentOS6.5 (2.6.32-431) I have 4 guest VMs running each w/ 2G of memory. Their disk images are local files. The host machine is also running a ...
1
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0answers
24 views

Does an NFS client incur read/write page faults proportional to bytes read to/written from server?

Perhaps my knowledge of virtual memory has been supplanted by too much other junk. Recently I ran some database benchmark tests where all data was to be stored on an NFS server and accessed via NFSv3 ...
0
votes
0answers
78 views

Linux vm.vfs_cache_pressure affect page cache or not?

I want to limit page cache in linux. Some documents say increase vm.vfs_cache_pressure to control the kernel reclaim memory. I try, but not work. Linux/Documentation/sysctl/vm.txt say "Decreasing ...
0
votes
0answers
21 views

Does Microsoft SQL Server have something similar to 'sqlite:///:memory:'?

Python 2.7 SQLAlchemy Microsoft SQL Server Management Studio 10.50.2500.0 Microsoft Analysis Services Client Tools 10.50.2500.0 Microsoft Data Access Components ...
3
votes
0answers
100 views

Linux max. value for vm.max_map_count

I'm planning to increase significantly the default value of 65k max mappings; let's say multiply by 10. Assuming we have enough memory on the machine is there anything I should take care of doing that?...
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). ...
4
votes
0answers
231 views

Why does Windows Server 2012 R2 Standard edition show only 20% of my available memory?

Fellow Techies-- I have a LENOVO x3650 X6/x64 based Windows server with 4 18 cores/36 logical processors-- with installed physical memory (ram) @1.5 TB, total virtual memory @1.5 TB. However, I am ...
3
votes
1answer
256 views

Virtualization limits for Ubuntu Server 14.04 LTS with KVM?

Essentially I'm after something like this: Virtualization limits for Red Hat Enterprise Linux with KVM but for Ubuntu Server 14.04 LTS. I'm trying to create some KVM guests with very large 1TB+ RAM ...
0
votes
0answers
61 views

CentOS 6.7 VM missing “Committed_AS” line in /proc/meminfo

The system is a virtual machine, and cat /proc/meminfo is missing the "Committed_AS" line which causes the some application processes to fail. [root@node1 ~]# more /etc/centos-release CentOS ...
0
votes
0answers
102 views

File writes stall during heavy disk I/O on Linux box

I have two processes running on my box => A and B. Whenever there is heavy disk I/O activity caused by writing large files to the disk by process A, I see that file writes in process B are stalling ...
33
votes
6answers
30k views

swap partition vs file for performance?

What is better for performance? A partition closer to the inside of the disk will have slower access times, and we must wait for the drive to switch between the OS and swap partitions. On the other ...
8
votes
5answers
7k views

Understanding virtual memory usage > swap + physical on Linux

I have a process that is reporting in 'top' that it has 6GB of resident memory and 70GB of virtual memory allocated. The strange thing is that this particular server only has 8GB physical and 35GB of ...
1
vote
1answer
149 views

Available virtual memory size is less then pagefile size

When Windows runs out of memory commit size it starts showing 'Low memory' window and performs slowly. This low-memory warning is not directly related to free physical memory amount. One can have 7Gb ...
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votes
1answer
132 views

Increase of Virtual Memory after update of CentOS7

I have made system updates on CentOS7 and now my Virtual Memory is full used. Before the updates the virtual memory was completely empty/swap Why? Is it a problem? How can I decrease the virtual ...
2
votes
1answer
46 views

How do you know when server memory needs to be increased?

I have a VPS running a few websites for clients. Running free -h shows the following: ~$ free -h total used free shared buffers cached Mem: 994M ...
3
votes
3answers
8k views

How do I find the root cause of Memory pressure failure on an SQL server 2008?

One of the servers I have been performance monitoring started throwing the following warnings from the Resource-Exhaustion-Detector: Windows successfully diagnosed a low virtual memory condition. ...
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votes
2answers
1k views

MSSQL 2008 r2 Express: there is insufficient system memory in resource pool 'internal' to run this query

I'm experiencing this error during the lifecycle of my DotNetNuke Installation. I've change the hosting server and now I've got a Windows Server 2012 with IIS 8 an SQL server 2008 r2 Express running ...
0
votes
0answers
302 views

linux system slab cache proc_node_cache usage too large

My system run java program only, at some time the memory usage increase very quickly to a very hight percentage: memory usage of java : PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ ...
3
votes
1answer
4k views

How to tune system settings for mongoDB on Linux?

Trying to squeeze a lot out of one question here -- please bear with me. Although the MongoDB man pages make several useful recommendations about system settings like ulimit (http://docs.mongodb.org/...
2
votes
2answers
974 views

Linux virtual memory tuning to workaround disk I/O issue

I am having a problem with a Linux server that it is writing to much to disk, thus I am having a slow response time due to a big IO wait. I already check smart values for the disks and are OK. This is ...
3
votes
1answer
846 views

What is shrink_slab, and why is it showing up in /var/log/messages?

I'm investigating some application issues on a Linux system and noticed this around the time of the most recent problem, but not close enough to be definitively related: Jun 7 17:51:49 localhost ...
1
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0answers
48 views

Why is my server using swap even though there is lots of RAM available? [duplicate]

My server has 24 cores, 16 GB RAM, and 8 SSDs on raid 0 (I think). I've noticed it is now using a low of swap space, even though there is plenty of RAM available. load average: 2.70, 2.54, 2.50 Mem: ...
0
votes
3answers
100 views

Load balancing for a running server process with sessions

I'm developing a server application that accepts incoming connections and works with client applications. The customer wants to have two machines working: in case one goes offline, the second will ...
0
votes
1answer
305 views

Can high disk cache usage lead to external fragmentation and ultimately to page allocation failures?

We're getting page allocation failures on a Linux server (3.2 kernel). We've been told the problem is directly related to the high use of the memory for cache; this would lead to external ...
0
votes
0answers
205 views

What is using all of my memory on Ubuntu 12.04?

I keep getting alarms from Rackspace telling me that my memory usage is too high, but I can't seem to find the culprit. I ran top SHIFT + M to see top output sorted by memory, and this is what I get (...
15
votes
1answer
8k views

Difference Between Private Memory Limit and Virtual Memory Limit in IIS

I want to set the max limit on the physical memory an application can use in IIS 7. Should I set a limit on Private Memory Limit or Virtual Memory Limit? Can some one point me to documentation of all ...
10
votes
3answers
43k views

How do I tell what process is causing kswapd to be in use?

I see kswapd using 100% CPU... how can I tell on which process's behalf kswapd is being used so much?
1
vote
1answer
10k views

What is nonpaged pool?

I have a Server 2008 R2 that I maintain on a day-to-day basis. The server is good and operating fine but it keeps sending me event 2019 error logs. "The server was unable to allocate from the system ...
0
votes
1answer
417 views

MongoDB: big size of mapped memory

I'm not expert in mongo memory management but some things confuse me. I use Mongo 2.4.9 and I have a replica sets for three nodes. I have performed db.serverStatus().mem and see that size of mapped is ...
1
vote
2answers
674 views

Cherokee high virtual memory usage even after disabling I/O Cache

I've Ubuntu 10.04LTS 64-bit running on a openvz container and Cherokee 1.0.8 compiled from source. The virtual memory usage of cherokee-worker is around 430 MB even after disabling I/O cache from ...
3
votes
3answers
712 views

High Memory 64bit server, not using all ram

I have several high memory linux servers running centos 64bit, and after 10-20 days of uptime I have noticed on all of these servers they dont actually use all the ram available to then (they all have ...
2
votes
1answer
167 views

How to interpret increasing SHR reported by top?

The man page for top defines SHR as: t: SHR -- Shared Mem size (kb) The amount of shared memory used by a task. It simply reflects memory that could be potentially shared with other ...
1
vote
2answers
1k views

Where's the Swap File/Partition?

I'm investigating the virtual memory configuration of a Debian based Amazon EC2 instance, and as my background isn't in system admin, I'm slightly confused by what I'm seeing. We're using MongoDB, ...
6
votes
2answers
2k views

Memory overcommitment on VMware ESXi 5.0

I would like to understand better the possibilities of VmWare ESXi memory overcommitment. I've read this paper from VmWare, so I am familiar with general concepts, such as hypervisor swapping, memory ...
1
vote
0answers
60 views

Stack , data and address space limits on an Ubuntu server

I am running an Ubuntu server which has around 5000 users. The users are allowed to SSH in to the system. So in order to cap the memory used up by a process I have capped the address space limits ...
1
vote
1answer
3k views

Large virtual memory size of ElasticSearch JVM

I am running a JVM to support ElasticSearch. I am still working on sizing and tuning, so I left the JVM's max heap size at ElasticSearch's default of 1GB. After putting data in the database, I find ...
2
votes
1answer
4k views

Mysql using high VIRT memory and RES is compartively

is there a way to reduce the VIRT mem usage? I am not sure what the reason is for such high usage. It has reached upto 12g as well. Using top command Tasks: 348 total, 1 running, 344 sleeping, 0 ...
1
vote
1answer
5k views

Running out of memory, or running out of disk space?

I'm running a database loading process (osm2pgsql) which is failing: Processing: Node(17404k 148.8k/s) Way(1351k 6.38k/s) Relation(9520 29.94/s)way_done failed: ERROR: could not extend file "base/...
1
vote
1answer
79 views

Virtual memory and CPU usage catch 20/20?

I am looking at this system below with ensuring we have enough memory to carry out day to day tasks, we have been hitting a bottleneck recently because there was only a 2GB page file, I've changed ...
1
vote
1answer
313 views

SQL Server Page File On 3TB San Drive

We have a Windows Server 2008 R2 box with 288GB of RAM. The system has created a page file about about the same size. This is expected, however, when I try to move the file to a SAN drive that is ...
2
votes
1answer
112 views

What is System Code Total Bytes

I am trying to use perfmon, and according to MSDN, the "System Code Total Bytes" counter ... Shows the size, in bytes, of pageable operating system code currently in virtual memory. It is a ...
0
votes
2answers
332 views

how to access physical memory in BSD platform from terminal or using any system call ?

i just not know how to use mem command in BSD to access physical memory or virtual memory to get the ACPI tables and their Address ....... $mem Enter mem command not found .... so what can i do ? ...
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votes
1answer
2k views

How is the Total Virtual Memory Calculated in this server? [closed]

From the images below, I am not sure how the 'Total Virtual Memory' available is shown as 7.82 GB in the system information (winmsd.exe) ? I always though it is nothing but the page file size ...
0
votes
1answer
75 views

Windows Pagefile placement

Is it possible to reserve a desired region of a given hard disk drive for placement of the pagefile.sys before enabling the page file on that drive?
-4
votes
4answers
916 views

What is the *optimal* virtual memory configuration for this server? [closed]

I am maintaining a Small Business Server 2003 (x86) server, that was originally installed and configured by someone else in early 2009. Recently, although we have never had any obvious memory-related ...
5
votes
2answers
625 views

Automatically suspend/hibernate a process when too much memory taken

I'm running a small Debian compute cluster on 8-core PCs with 16GB of RAM. I'm running batches of about 1k tasks (each batch has a total expected time of a month to be finished). A single task is ...