03-21-2005
Buffer Cache
What is the "Buffer Cache" used for?
10 More Discussions You Might Find Interesting
1. Filesystems, Disks and Memory
anybody please tell me how do i get all the information
about buffer cache in hp-ux .if anybody familiar with the system
call them please specify .
i found the extern variables in /sys/buf.h . but that didn't help .:) (2 Replies)
Discussion started by: vish_shan
2 Replies
2. UNIX for Advanced & Expert Users
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. Solaris
Does anyone know how the unix buffer / cache is set in a Solaris based system ?
( I presume it is a kernel based setting )
I notice from SAR -d that my read cache is consistently at 100% but my write cache frequently falls below 65%. What does this mean. Should I be tuning the write cache and... (1 Reply)
Discussion started by: jimthompson
1 Replies
4. Red Hat
hi everyone,
can any one help change the buffer cache size in redhat and suse?? this error i got when i installed oracle 10g and it went well and when i try to mount the database using startup cmd it says too many buffer cache parameters (error code : ora-1034)
thnq in advance (0 Replies)
Discussion started by: gsr_kashyap
0 Replies
5. UNIX for Dummies Questions & Answers
Hi,
Is it possible to reduce the amount of buffer cache in the memory allocation of a Unix Server? If so where can I do that?
Also, does buffer cache count as tied up memory, or will it decrease as more memory is requested by other programs. (1 Reply)
Discussion started by: dehuang83
1 Replies
6. Filesystems, Disks and Memory
Hi,
I am trying to understand the role of buffer cache in block I/O.
I am monitoring /proc/meminfo, my question is does the value of 0 for 'buffers', mean that any subsequent disk read issued by a process, would get the data physically from the disk, and not an allocated buffer for the block?
... (1 Reply)
Discussion started by: jake24
1 Replies
7. Linux
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. 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
9. UNIX for Advanced & Expert Users
I was reading a book on UNIX internals "The design of the UNIX Operating system." There are two memory structures that are confusing me:
1) Buffer cache
2) Inode cache
My questions are
1) Does a process get both buffer cache and Indoe cache allocated when it opens/creates a file?
2) if no,... (1 Reply)
Discussion started by: sreeharshasn
1 Replies
10. Shell Programming and Scripting
Moderators,
Please excuse if I am in the wrong section.
I have a question that someone may know the answer to. We know that a current bash shell keeps a record of all commands in a buffer. When the shell is terminated this buffer is written out to ~/.bash_history for the user.
I know... (2 Replies)
Discussion started by: jaysunn
2 Replies
LEARN ABOUT DEBIAN
cache::filecache
Cache::FileCache(3pm) User Contributed Perl Documentation Cache::FileCache(3pm)
NAME
Cache::FileCache -- implements the Cache interface.
DESCRIPTION
The FileCache class implements the Cache interface. This cache stores data in the filesystem so that it can be shared between processes.
SYNOPSIS
use Cache::FileCache;
my $cache = new Cache::FileCache( { 'namespace' => 'MyNamespace',
'default_expires_in' => 600 } );
See Cache::Cache for the usage synopsis.
METHODS
See Cache::Cache for the API documentation.
Clear( [$cache_root] )
See Cache::Cache, with the optional $cache_root parameter.
Purge( [$cache_root] )
See Cache::Cache, with the optional $cache_root parameter.
Size( [$cache_root] )
See Cache::Cache, with the optional $cache_root parameter.
OPTIONS
See Cache::Cache for standard options. Additionally, options are set by passing in a reference to a hash containing any of the following
keys:
cache_root
The location in the filesystem that will hold the root of the cache. Defaults to the 'FileCache' under the OS default temp directory (
often '/tmp' on UNIXes ) unless explicitly set.
cache_depth
The number of subdirectories deep to cache object item. This should be large enough that no cache directory has more than a few
hundred objects. Defaults to 3 unless explicitly set.
directory_umask
The directories in the cache on the filesystem should be globally writable to allow for multiple users. While this is a potential
security concern, the actual cache entries are written with the user's umask, thus reducing the risk of cache poisoning. If you desire
it to only be user writable, set the 'directory_umask' option to '077' or similar. Defaults to '000' unless explicitly set.
PROPERTIES
See Cache::Cache for default properties.
(get|set)_cache_root
See the definition above for the option cache_root
(get|set)_cache_depth
See the definition above for the option cache_depth
(get|set)_directory_umask
See the definition above for the option directory_umask
SEE ALSO
Cache::Cache
AUTHOR
Original author: DeWitt Clinton <dewitt@unto.net>
Last author: $Author: dclinton $
Copyright (C) 2001-2003 DeWitt Clinton
perl v5.12.4 2009-03-01 Cache::FileCache(3pm)