Recently I found a paper in ACM Library describing two distributed file systems with the following features:

• distributed read-write locking at the byte granularity;
• user visible distributed transactions with isolation and roll-back;
• capability based authentication;
• files implemented as B-trees;
• distributed garbage collection of ( Read more... )

How to keep a couple of linux kernel developers busy for a day:

Click to view

1. Introduction.
This article describes results of a bit of research I made on efficiency of file system cache replacement algorithms. As everybody knows file system tries to keep some portions of its backing secondary storage (disk) cached in the primary storage (memory). In particular portion of file system data or meta-data that is being ( Read more... )

Dedicated to VM and file system developers and researches...

It is immediately apparent from these figures that moving-arm disks should never be used, neither for paging applications nor for any other heavy-traffic auxiliary memory applications.

Peter J. Denning -- Virtual Memory.

--Tags:-[Kernel]-[VM]-----------

reiser4: 1. internal tree

This continues previous entry: introduction

• 0. B-trees overview
  
• 1. lookup and modification
  
• 2. lookup optimizations
  

0. B-trees overview



B-tree is am umbrella term for a variety of similar algorithms used to implement dictionary abstraction suitable in a form suitable for external ( Read more... )

Subject: [ntdev] WdfUsbTargetDeviceSendControlTransferSynchronously and timeouts

update: Like this wasn't enough.

Below are excerpts from

find . -name \*dll | xargs strings -- | grep -i '^[a-z0-9_]*$' | awk '{ print length($1) "\t" $1 }' | sort -n

output (executed in WinXP system directory):

50 ( Read more... )

ext3 htree code in Linux kernel implements peculiar version of balanced tree used to efficiently
handle large directories.

htree directory consists of block sized nodes. Some of them (leaf nodes)
contain directory entries in the same format as ext2. Other nodes contain
index: they are filled with hashes and pointers to other nodes ( Read more... )

( Read more... )

reiser4: 0. introduction

This is an introduction to the series of entries I am going to write about
reiser4 file system. The plan, for the time being, goes like this:

• 0. introduction
  
  • 0. trivia
    
  • 1. reiser4 strong points
    
  • 2. architecture overview
    
• 1. internal tree
  
  • 0. B-trees overview
    
  • 1. lookup and modification ( Read more... )

Here is a 2.6.15-rc1 version of opahead patch that was sleeping in my patch-scripts series file for some time.

opahead stands for operation-ahead by analogy with read-ahead. An inspiration for this patch was a USENIX paper that discusses a smarter than usual read-ahead algorithm. Kroeger and Long implemented a sub-system that kept track of read ( Read more... )