The following table describes key features of the NSS File System and the NetWare Traditional File System for OES NetWare and NetWare 6.5:
|
Feature Description |
NSS File System |
NetWare Traditional File System |
|---|---|---|
|
Management interfaces |
Novell Remote Manager for NetWare (limited feature set) |
|
|
Device and partition management |
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|
File system management for directories and files |
Novell Client™ NW 6.5 SP8: NetStorage Administration Guide (via Web browser only, not WebDAV) Novell Remote Manager for NetWare Rights utility for NetWare |
Novell Client NW 6.5 SP8: NetStorage Administration Guide (via Web browser only, not WebDAV) |
|
Interface |
64-bit |
32-bit |
|
File access protocols |
NCP™ Native File Access Protocols (AFP, CIFS, AFP) |
NCP |
|
Character format |
Unicode |
ASCII double-byte |
|
Maximum device size recognized (physical or logical) |
2 TB |
2 TB |
|
Minimum device size (physical or logical) (needed to create a pool or Traditional volume) |
10 MB |
10 MB |
|
Maximum software RAID device size (combined total of all member segments) |
2 TB |
Not applicable |
|
Minimum software RAID segment size |
12 MB per segment |
Not applicable |
|
Maximum partition size |
2 TB |
1 TB |
|
Minimum partition size |
10 MB |
10 MB |
|
Maximum number of partitions (logical or physical devices) per NSS pool or Traditional volume |
No practical limit, but the combined size cannot exceed the maximum NSS pool size of 8 TB. |
Up to 32 partitions, but the combined size cannot exceed the maximum Traditional volume size of 1 TB. |
|
Maximum NSS pool or Traditional volume size |
8 TB An NSS pool of 8 TB requires at least 4 segments of up to 2 TB each. You can combine any number of partitions (where each is 10 MB to 2 TB in size), but the combined size cannot exceed 8 TB. |
1 TB A Traditional volume of 1 TB requires 1 to 32 partitions of 10 MB to 1 TB in size, but the combined size cannot exceed 1 TB. |
|
Minimum NSS pool or Traditional volume size |
10 MB |
10 MB |
|
Maximum file size |
Up to 8 TB per file, depending on the volume size and available space in the volume. |
Up to 4 GB per file, depending on the volume size and available space in the volume. |
|
Maximum number of files per volume (The practical limit is the number of files that can be handled by the file browser or application.) |
Up to 8 trillion, regardless of how many name spaces are loaded. |
Up to 16 million files with 1 name space. The practical limit is up to 4 million files with 3 name spaces. |
|
Maximum number of files open concurrently |
1 million |
100 thousand |
|
Maximum number of data volumes mounted concurrently per server |
255 plus the sys: volume. You can mount NSS volumes beyond 256, but they are not visible or accessible through the normal Netware APIs. |
255 plus the sys: volume. |
|
Maximum size of a volume |
Up to 8 TB, depending on the pool size and available space in the pool. If a pool contains multiple volumes, the cumulative administrative maximum sizes of all volumes can exceed the pool size by using the overbooking feature, although real total size is bound by physical limitations. Because space is allocated to volumes as needed, a volume might not reach its quota. |
Up to 1 TB. The total size allocated for all volumes on the server cannot exceed the physical size of all devices combined, so overbooking is not possible. Unused space goes to waste if volumes grow unevenly. |
|
Time to mount a volume |
Only a few seconds. NSS uses a journaling file system and does not need to scan the entire file system to create a directory entry table (DET) and to load a File Allocation Table (FAT). |
Up to several minutes, depending on volume size. The mount process scans the entire file system to create a DET before loading the volume. The time to mount increases based on the number of files, the number of name spaces used, and the size of the files. The mount process also loads the volume’s FAT. Volumes with a smaller block size require more server memory to mount and manage, and it takes longer to mount the volume. |
|
Volume name space |
Accommodates all name spaces and requires less memory to mount than Traditional volumes. |
Each name space you add to a Traditional volume requires additional server memory. If you add name space support to a volume and do not have enough memory, that volume cannot be mounted. |
|
Minimum server memory required to activate a volume |
Requires only 1 MB of available RAM to activate a single volume of any size and any number of files. Loads a file’s metadata into memory only as you access the file. |
Loads the DET into memory at the time of the mount. The amount of memory required increases with volume size and number of files. For a maximum volume size and number of objects, the memory required can be up to 1 GB just to activate the volume. |
|
File access time |
Same for each file, regardless of its location on the volume. |
Depends on the file’s location on the volume. |
|
File save time |
Offers the Flush Files Immediately attribute for NSS volumes to write files to disk on save instead of waiting for the next disk write cycle. This helps prevent possible data loss between disk write cycles and helps ensure data integrity. |
Caches file in memory until the next disk write cycle. |
|
File compression |
Yes The smallest file size that is eligible for compression is 8192 + 1 bytes. NSS does not have suballocation so each file takes up a multiple of 4K instead of 512 bytes. |
Yes The smallest file size that is eligible for compression is 512 + 1 bytes. |
|
Volume encryption |
Yes |
No |
|
Error correction and data recovery time on system failure |
Journaling file system logs changes. On system failure, replays the most recent transactions to confirm validity, then repairs errors or rolls back to the original condition, typically in 15 to 60 seconds, unless the volume is corrupted. If the volume is corrupted, repair can take up to several hours, depending on the volume size. |
Must verify the entire volume contents with vrepair.nlm, which can take several hours, depending on the volume size. |
|
Software RAID support |
RAID 0 (striping) RAID 1 (mirroring) RAID 5 (striping with parity) RAID 10 (mirroring RAID 0 devices) RAID 15 (mirroring RAID 5 devices) |
RAID 0 (striping) RAID 1 (mirroring) RAID 10 (mirroring RAID 0 devices) |
|
Data shredding |
Yes, up to 7 times |
No |
|
Transaction Tracking System™ (TTS™) |
Yes Requires exclusive use per server. To use TTS, first disable TTS for all Traditional volumes, and then enable TTS for your NSS volumes. |
Yes Requires exclusive use per server. Use for Traditional or for NSS, but not for both on the same server. TTS is enabled by default. |
|
Directory quotas and User space quotas |
Yes |
Yes, enabled by default |
|
Salvage subsystem |
Yes, for deleted directories and files |
Yes, for deleted files |
|
File snapshot attribute (make a temporary snapshot copy of an open file for backup) |
Yes; allows backup of open files without deactivating the volume. |
No |
|
Pool snapshot (retain point-in-time version of a pool using block-level copy on write) |
Yes; allows backup of block-level changes, without deactivating the volume. Uses a brief freeze-release process to capture information for last remaining open files. |
No |
|
Backup support |
Reviews a journaled list of files modified since the previous backup. |
Does not have list of modified files. It must scan the entire file system to identify files modified since the previous backup. |
|
Backup systems support |
TSA, TSA600 for files over 2 GB, SMS, and Enhanced SBackup |
TSA, SMS, and Enhanced SBackup |
|
Device maintenance support |
Activate and deactivate devices by pool. |
Activate and deactivate devices by Traditional volume. |
|
CD and DVD device recognition |
Default process with full support for ISO 9660 and Macintosh HFS formats. Use CDs and DVDs as read-only NSS volumes. |
CDs and DVDs cannot be Traditional volumes in NetWare 6.5. |
|
Operating system version detection |
Default process |
Manual process |
|
DOS FAT compatible |
Yes |
No |
|
Ability to access DOS partitions on the NetWare server |
Load dosfat.nss to treat as a standard NSS volume. |
No |
|
Block suballocation |
Unnecessary; superseded by technology. |
Yes |
|
Auditing |
Unnecessary; superseded by technology. |
Yes |
|
filename locks |
Unnecessary; superseded by technology. |
Yes |
|
Data migration |
Yes |
Yes |