File system comparison
These tables summarize the features and limitations of each file system.
Capability | "root" (/) | QOpenSys | QSYS.LIB16 | QDLS | QNTC |
---|---|---|---|---|---|
Standard part of IBM® i | Yes | Yes | Yes | Yes | Yes |
Type of file | Stream | Stream | Record 12 | Stream | Stream |
File size limit | T2=1 TB; T1=128 GB | T2=1 TB; T1=128 GB | Database file sizes | 4 GB | Varies 17 |
Access through IBM i file server | Yes | Yes | Yes | Yes | Yes |
Direct access through file server I/O processor 1 | No | No | No | No | Yes |
Comparative speed for open/close | Medium 2 | Medium 2 | Low 2 | Low 2 | Medium 2 |
Case-sensitive name search | No | Yes | No 4 | No 5 | No |
Maximum length of each component in path name | 255 characters 3 | 255 characters 3 | 10/6 characters 6 | 8/3 characters 7 | 255 characters 3 |
Maximum length of path name 8 | 16MB | 16MB | 55 – 66 characters4 | 82 characters | 255 characters |
Maximum length of extended attributes for an object | 2GB | 2GB | Varies 9 | 32KB | 0 18 |
Maximum levels of directory hierarchy within file system | No limit 10 | No limit 10 | 3 | 32 | 127 |
Maximum links per object 11 | Varies 15 | Varies 15 | 1 | 1 | 1 |
Supports symbolic links | Yes | Yes | No | No | No |
Object or file can have owner | Yes | Yes | Yes | Yes | No |
Supports integrated file system commands | Yes | Yes | Yes | Yes | Yes |
Supports integrated file system APIs | Yes | Yes | Yes | Yes | Yes |
Supports hierarchical file system (HFS) APIs | No | No | No | Yes | No |
Threadsafe 13 | Yes | Yes | Yes | No | Yes |
Supports object journaling | Yes | Yes | Yes14 | No | No |
Notes:
Abbreviations
|
Capability | QOPT | QFileSvr.400 | UDFS | NFS |
---|---|---|---|---|
Standard part of IBM i | Yes | Yes | Yes | Yes |
Type of file | Stream | Stream | Stream | Stream |
File size limit | 4 GB | Varies 3 | T2 = 1 TB; T1=128 GB | Varies 14 |
Access through IBM i file server | Yes | Yes | Yes | Yes |
Direct access through the file server I/O processor 1 | No | No | No | No |
Comparative speed for open/close | Low | Low 2 | Medium 2 | Medium 2 |
Case-sensitive name search | No | No 2 | Yes 11 | Varies 2 |
Maximum length of each component in path name | Varies 4 | Varies 2 | 255 characters 15 | Varies 2 |
Maximum length of path name 5 | 294 characters | No limit 2 | 16 MB | No limit 2 |
Maximum length of extended attributes for an object | 8 MB | 0 6 | 2 GB 10 | 0 6 |
Maximum levels of directory hierarchy within file system | No limit 7 | No limit 2 | No limit 7 | No limit 2 |
Maximum links per object 8 | 1 | 1 | Varies 13 | Varies 2 |
Supports symbolic links | No | No | Yes | Yes 2 |
Object or file can have owner | No | No 9 | Yes | Yes 2 |
Supports integrated file system commands | Yes | Yes | Yes | Yes |
Supports integrated file system APIs | Yes | Yes | Yes | Yes |
Supports hierarchical file system (HFS) APIs | Yes | No | No | No 2 |
Threadsafe 12 | Yes | Yes | Yes | Yes |
Supports object journaling | No | No | Yes | No |
Notes:
Abbreviations
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