vm and buffer cache Post: 20448

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buffer cache information

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 .:)

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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...

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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

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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.

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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? ...

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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

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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...

LEARN ABOUT OSX

vfs_readahead

VFS_READAHEAD(8)														  VFS_READAHEAD(8)

NAME

       vfs_readahead - pre-load the kernel buffer cache

SYNOPSIS

       vfs objects = readahead

DESCRIPTION

       This VFS module is part of the samba(7) suite.

       This  vfs_readahead  VFS module detects read requests at multiples of a given offset (hex 0x80000 by default) and then tells the kernel via
       either the readahead system call (on Linux) or the posix_fadvise system call to pre-fetch this data into the buffer cache.

       This module is useful for Windows Vista clients reading data using the Windows Explorer program, which asynchronously  does  multiple  file
       read requests at offset boundaries of 0x80000 bytes.

       The offset multiple used is given by the readahead:offset option, which defaults to 0x80000.

       The size of the disk read operations performed by vfs_readahead is determined by the readahead:length option. By default this is set to the
       same value as the readahead:offset option and if not set explicitly will use the current value of readahead:offset.

       This module is stackable.

OPTIONS

       readahead:offset = BYTES
	  The offset multiple that causes readahead to be requested of the kernel buffer cache.

       readahead:length = BYTES
	  The number of bytes requested to be read into the kernel buffer cache on each readahead call.

       The following suffixes may be applied to BYTES:

       o  K - BYTES is a number of kilobytes

       o  M - BYTES is a number of megabytes

       o  G - BYTES is a number of gigabytes

EXAMPLES

	    [hypothetical]
	    vfs objects = readahead

VERSION

       This man page is correct for version 3.0.25 of the Samba suite.

AUTHOR

       The original Samba software and related utilities were created by Andrew Tridgell. Samba is now developed by the  Samba	Team  as  an  Open
       Source project similar to the way the Linux kernel is developed.

																  VFS_READAHEAD(8)

10 More Discussions You Might Find Interesting

1. Filesystems, Disks and Memory

buffer cache information

Discussion started by: vish_shan

2. HP-UX

Buffer Cache

Discussion started by: ALTRUNVRSOFLN

3. Solaris

Unix Cache / Buffer

Discussion started by: jimthompson

4. Red Hat

buffer cache size

Discussion started by: gsr_kashyap