This table is from the WSeB "Quick Beginnings" book.
|
|
(JFS) |
System (386 HPFS) |
System (HPFS) |
|
|
Maximum volume size |
2TB (terabytes) |
64GB (gigabytes) |
64GB (gigabytes) |
2GB (gigabytes) |
|
Maximum file size |
2TB (terabytes) |
2GB (gigabytes) |
2GB (gigabytes) |
2GB (gigabytes) |
|
Maximum file name length |
254 characters (bytes) |
254 characters (bytes) |
254 characters (bytes) |
11 (8.3 format) characters |
|
Allows spaces and periods in file names |
Yes |
Yes |
Yes |
No; however, a period is required between file name and extension |
|
Standard file and directory attributes (bit flags) |
Within file system |
Within file system |
Within file system |
Within file system |
|
Extended attributes (64KB text or binary with keywords) |
Within file system |
Within file system |
Within file system |
In a separate file |
|
Maximum path length |
260 characters (bytes) |
260 characters (bytes) |
260 characters (bytes) |
64 characters (bytes) |
|
Bootable file system |
No |
Yes |
Yes |
Yes |
|
Logical volume type |
LVM only |
LVM or compatibility (must be compatibility for Fault Tolerance) |
LVM or compatibility |
LVM or compatibility |
|
Allows dynamic volume expansion |
Yes |
No |
No |
No |
|
File system scales up when using SMP |
Yes |
No |
No |
No |
|
Allows for fault tolerance |
No |
Yes |
No |
No |
|
Allows for local security |
No |
Yes |
No |
No |
|
Requires a separate proof of license during installation |
No |
Yes |
No |
No |
|
Average wasted space per file |
1/2 block size (256 to 2048 bytes) |
1/2 sector (256 bytes) |
1/2 sector (256 bytes) |
1/2 cluster (1 KB to 16KB), approximately 0.001% of volume |
|
Allocation information for files |
Near each file in its INODE |
Near each file in its FNODE |
Near each file in its FNODE |
Centralized near front of volume |
|
Free disk-space information |
Centralized in file structure represented by B+tree |
Located near free space in bit maps |
Located near free space in bit maps |
Centralized near front of volume |
|
Directory structure |
Sorted B+tree |
Sorted B-tree |
Sorted B-tree |
Unsorted linear list; must be searched exhaustively |
|
Directory location |
Close to files it contains |
Located near seek center of volume |
Located near seek center of volume |
Root directory at front of volume; others scattered |
|
Read-ahead |
32MB |
Sensitive to data type |
Cache reads in 8KB blocks |
Optional |
|
Cache replacement strategy |
Segmented least recently used (LRU) algorithm |
Sensitive to data type |
Modified least recently used (LRU) algorithm |
Simple least recently used (LRU) algorithm |
|
Write-behind (lazy write) |
Optional; can be handled on a per-file basis |
Optional; can be handled on a per-file basis |
Optional; can be handled on a per-file basis |
Optional; can be handled on a per-file basis |
|
Caching program |
None; lazy write parameters can be set on the IFS=JFS.IFS line in the CONFIG.SYS
file) |
CACHE386-EXE (values specified for the IFS and RUN statements in the CONFIG.SYS
file) and HPFS386.INI |
CACHE.EXE (in the CONFIG.SYS file) |
DISKCACHE (in the CONFIG.SYS file) |
|
Maximum cache size |
Physical memory available |
Physical memory available |
2MB |
14MB |
|
Cache threshold |
No cache threshold |
Sensitive to data type |
Variable, up to 64KB |
Variable, up to 64KB; 3.5KB default |
|
LAN Server access control lists |
Within file system |
Within file system |
In separate file (NETACC) |
In separate file (NETACC) |
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| Send mail to Al about this page. | Last updated 16-Sep-2001 |