Group: file system

topics > computer science > Group: operating system

data caching
device driver
disk allocation
examples of file systems
file cache
file directory
file input/output
file system reliability
computer hardware

client-server model for distributed systems
hierarchical structures
I/O streams
name server or name directory
security by access rights
uniform reference to data


A file system stores persistant data as files. It needs quick access, high throughput, high reliability, ease of expansion, and robust against hardware failures. (cbb 12/07)
Subtopic: goals up

Quote: a file system should be high performance, robust against some software errors, and use available hardware [»hagmR_1987]

Subtopic: capacity vs. latency up

Quote: storage capacity doubles every year while access time improves at 10% per year; increasingly difficult to extract data [»grayJ6_2003]
Quote: transfer huge databases by transfering complete computers [»grayJ6_2003]
Quote: error rates have remained constant while capacity and bandwidth have increased tremendously [»browD9_2007]

Subtopic: file server up

Quote: Star file drawers correspond to a shared file server with access rights [»smitDC_1982]

Subtopic: file system up

Quote: use a file system instead of cards and tape for on-line interaction; device independent, unlimited storage, symbolic addresses [»daleRC_1965]
Quote: file system implemented in Multics [»daleRC_1965]

Subtopic: file system as global state up

Note: a file system or database is global state accessed by name [»cbb_2000, OK]

Subtopic: typed files up

Quote: DSEE's Domain/OS manages files by their type; a type implements one or more traits of related operations; e.g., the protection trait [»lubkD6_1991]

Subtopic: database up

Quote: a database does not see files as character arrays; perhaps database functions should be the low level facility [»stonM7_1981]

Subtopic: optimization up

Quote: performance analysis of prefetching; significant gains from disk caching, I/O amortization, seek time reduction, and overlapped computation and I/O [»shriE6_1999]
Quote: file system model predicted response time within 9% error; simplified analysis of prefetching [»shriE6_1999]
Quote: read the entire cluster when reading a disk block [»shriE6_1999]

Subtopic: pooled storage up

Quote: treat file storage like memory; plug in disks as needed; allocate and release space from a storage pool [»browD9_2007]

Subtopic: cached files up

Quote: allocate a disk cache segment for each concurrent process accessing a file [»shriE6_1999]

Subtopic: free page management up

Quote: all free pages kept in OS6's free storage file, in cache memory, and on backup disk [»stoyJE3_1972]
Quote: a page's label (file id etc) is always checked before writing; only written when freed or defined [»lampBW4_1974]
Quote: UNIX partitions disks into cylinder groups with copy of superblock, local inodes, free block bit map, and usage statistics [»mckuMK8_1984]
Quote: rebuilding reads all the labels, gets full names for all files, gets free pages, checks directories; takes 30 seconds [»lampBW4_1974]
Quote: the bit table for free disk pages is a hint, verified against the label of the free page [»lampBW10_1983]
Quote: free disk bit map for UNIX at fragment level, but blocks are aligned [»mckuMK8_1984]

Subtopic: file usage up

Quote: large-scale study of 10,000 Windows file systems at Microsoft [»doucJR5_1999]
Quote: if exclude system files, 99.5% of all changes to a file are by the previous writer [»kistJJ2_1992]
Quote: if exclude system files, the chance of different users modifying the same object within a week is less than 0.4%
Quote: file sizes are log-normal across file systems; 4 KB median by frequency, 2 MB median by size, 64-128 KB mean file size, correlated with extension [»doucJR5_1999]
Quote: median directory size is 2 files with 18% containing no files [»doucJR5_1999]
Quote: 69% of all directories have no subdirectories, 16% with one subdirectory, 15% at depth of 8 or greater
Quote: median file age of 48 days, excluding the vast majority of short-lived files [»doucJR5_1999]
Quote: 44% of files never used; of those used, median lifetime is 12 days of use; varies by job, e.g., tech support vs. admin

Subtopic: accounting up

Quote: each major client of a file server needs a charging capability to account for file creation and storage [»birrAD9_1980]

Subtopic: access control up

Quote: can associate an access list with each object that gives access codes for each domain; widely used for file systems [»dennPJ_1980]

Subtopic: history up

Quote: ASSIGN a|^1000 reserves a block of storage on the drum; uses one variable in memory

Group: file system up

Topic: data caching (35 items)
Topic: device driver (15 items)
Topic: disk allocation (32 items)
Topic: examples of file systems (44 items)
Topic: file (22 items)
Topic: file cache (23 items)
Topic: file directory (55 items)
Topic: file input/output (21 items)
Topic: file system reliability
(26 items)

Related Topics up

Group: computer hardware   (24 topics, 343 quotes)
Group: database   (27 topics, 665 quotes)

Topic: client-server model for distributed systems (25 items)
Topic: hierarchical structures (46 items)
Topic: I/O streams (17 items)
Topic: name server or name directory (40 items)
Topic: security by access rights (38 items)
Topic: uniform reference to data
(34 items)

Updated barberCB 8/05
Copyright © 2002-2008 by C. Bradford Barber. All rights reserved.
Thesa is a trademark of C. Bradford Barber.