Sponsored Content
Full Discussion: Linux cache
Operating Systems Linux Linux cache Post 302597448 by Corona688 on Friday 10th of February 2012 10:38:58 AM
Old 02-10-2012
You are having the standard Linux Newbie Memory Freakout. Cache memory counts as free memory.

Linux uses every spare bit of memory to cache all disk accesses, because memory which sits around doing nothing is useless. But cache will be recycled for other uses as needed. It's only sitting around as cache right now because it's not needed. Large amounts of cache are to be expected on an unloaded and idle system.

You want to have at least some cache, anyway. If you use so much memory that there's nothing left for cache, this is a problem -- disk access will become slow. The more cache you have, the more efficient disk access can become.

Do not, repeat, do not reboot your system, plug weird values into /proc/ to "flush the cache", and so forth. Everything is fine.

Last edited by Corona688; 02-10-2012 at 11:45 AM..
This User Gave Thanks to Corona688 For This Post:
 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

UBC cache vs. Metadata cache

hi, What is the difference between UBC cache and Metadata cache ? where can i find UBC cache Hits and Metadata cache Hits in hp-ux? Advanced thanx for the help. (2 Replies)
Discussion started by: sushaga
2 Replies

2. UNIX for Advanced & Expert Users

vm and buffer cache

i have a serious doubht about the assignment of memory in hp-ux system . i read from somewhere that the page allocation in hp-ux is not unified unlike compaq . i wanted to know in hp-ux kernel ,once the pages are assigned for the univarsal buffer cache... (2 Replies)
Discussion started by: vish_shan
2 Replies

3. HP-UX

Buffer Cache

What is the "Buffer Cache" used for? (1 Reply)
Discussion started by: ALTRUNVRSOFLN
1 Replies

4. Solaris

ARP Cache

Dear all, We are testing two of our servers for mq series connectivity. The scenario is, when one machine is shutting down it's services there are some scripts that do a dns update, which removes the ip address and relates it to the ip address of the other node on our dns server, and the update... (7 Replies)
Discussion started by: earlysame55
7 Replies

5. Linux

Linux cache

Hi all I am trying to understand the kernel memory management and require assistance in this regard. Kernel first creates the cache memory to perform any subsequent allocation to processes. I could not figure out how it is accomplished. Do kernel directly allocates any hardware cache or allocates... (0 Replies)
Discussion started by: joshighanshyam
0 Replies

6. Programming

Manipulate the Linux ARP Cache in C

Hello, I need help on how to "access" or manipulate the Linux ARP Cache in C, here is the description of the project i'm working in: There are a lot of tools that analize ARP frames and send an e-mail to the sysadmin, that's easy. What i want to do is to inspect every ARP frame that arrives... (18 Replies)
Discussion started by: semash!
18 Replies

7. Linux

getting info on Cache Size, Data Cache etc..

Hi all I saw in Microsoft web site www.SysInternals.com a tool called CoreInfo from able to print out on screen the size of the Data and Instruction caches of your processor, the Locigal to Physical Processor mapping, the number of the CPU sockets. etc.. Do you know if in Linux is available a... (2 Replies)
Discussion started by: manustone
2 Replies

8. UNIX for Advanced & Expert Users

linux memory buffers & cache usage

18:45:47 # free -m total used free shared buffers cached Mem: 96679 95909 770 0 1530 19550 -/+ buffers/cache: 74828 21851 Swap: 12287 652 11635 Hi all. The below output is from a RHEL 4.5... (0 Replies)
Discussion started by: drummerrob
0 Replies

9. Linux

File cache /Page cache Linux

Hi All, could any one point out any open source test-suites for "File cache" testing and as well as performance test suites for the same. Currently my system is up with Linux/ext4. Regards Manish (0 Replies)
Discussion started by: hmanish
0 Replies

10. UNIX for Dummies Questions & Answers

Clearing memory cache on Linux server

i wish to clear memory cache on a production box and i was wondering what is the worst that can happen if i do? i already tested this on a backup server and everything seemed fine. but i need to know from you experts what are the worst things that can happen when i run it on a real server: ... (5 Replies)
Discussion started by: SkySmart
5 Replies
CACHEINFO(5)							AFS File Reference						      CACHEINFO(5)

NAME
cacheinfo - Defines configuration parameters for the Cache Manager DESCRIPTION
The cacheinfo file defines configuration parameters for the Cache Manager, which reads the file as it initializes. The file contains a single line of ASCII text and must reside in the /etc/openafs directory. Use a text editor to create it during initial configuration of the client machine; the required format is as follows: <mount>:<cache>:<size> where <mount> Names the local disk directory at which the Cache Manager mounts the AFS namespace. It must exist before the afsd program runs. The conventional value is /afs. Using any other value prevents traversal of pathnames that begin with /afs (such as pathnames to files in foreign cells that do use the conventional name). The -mountdir argument to the afsd command overrides this value. <cache> Names the local disk directory to use as a cache. It must exist before the afsd program runs. The standard value is /usr/vice/cache, but it is acceptable to substitute a directory on a partition with more available space. Although the Cache Manager ignores this field when configuring a memory cache, a value must always appear in it. The -cachedir argument to the afsd command overrides this value. <size> Specifies the cache size as a number of 1-kilobyte blocks. Larger caches generally yield better performance, but a disk cache must not exceed 90% of the space available on the cache partition (85% for AIX systems), and a memory cache must use no more than 25% of available machine memory. The -blocks argument to the afsd command overrides this value. To reset cache size without rebooting on a machine that uses disk caching, use the fs setcachesize command. To display the current size of a disk or memory cache between reboots, use the fs getcacheparms command. EXAMPLES
The following example cacheinfo file mounts the AFS namespace at /afs, establishes a disk cache in the /usr/vice/cache directory, and defines cache size as 50,000 1-kilobyte blocks. /afs:/usr/vice/cache:50000 SEE ALSO
afsd(8), fs_getcacheparms(1), fs_setcachesize(1) COPYRIGHT
IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved. This documentation is covered by the IBM Public License Version 1.0. It was converted from HTML to POD by software written by Chas Williams and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell. OpenAFS 2012-03-26 CACHEINFO(5)
All times are GMT -4. The time now is 02:53 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy