How do you interpret the Directory Entry information in the SERVMAN.NLM utility?

(Last modified: 31May2001)

This document (10023642) is provided subject to the disclaimer at the end of this document.

goal

fact

Novell NetWare 4.11

Formerly TID 2910030.

fix

There are four statistics in SERVMAN that report directory entry information. To find this information load SERVMAN / choose volume statistics / select a volume. The Volume Information screen will report:

     Directory size (blocks):
     Directory entries:
     Used directory entries:
     Extended directory space:

Block Size is the volume block size. When a volume is created you can set the volume block size to 4k, 16k, 32k, or 64k. The volume block size is only setable at the time the volume is created. After that it cannot be changed.

Directory size (blocks) is the number of VOLUME blocks that have been allocated. The NetWare operating system maintains two copies of the directory entry table (DET). Therefore the Directory size will reflect double the number of usable blocks. For example: if the Directory size (blocks) is reporting 380 blocks, the number of usable blocks for directory entries is actually 190 (or half of 380). 190 of the blocks are used for one copy of the directory entry table, and the other 190 blocks are used for the mirrored copy of the directory entry table.

Directory entries is the total number of USABLE directory entry slots that are allocated for directory entries. This number does not reflect the mirrored copy of the DET. Each directory entry occupies 128 bytes. Directory entry blocks are allocated in 4k chunks, or 4096 bytes (4 * 1024).

Used directory entries are the total number of 128 byte directory entry slots that have actually been used. As with the "Directory entries" statistic, this number does not reflect the mirrored copy of the DET. Note: Each file requires one directory entry slot for EACH name space installed. For example: If I have added MAC and OS/2 name space, each file will require three directory entry slots. 1 - 128 byte slot for DOS, 1 - 128 byte slot for MAC, and 1 - 128 byte slot for OS/2 .

When a directory entry block is allocated there are two different systems at work. The NetWare OS allocates, dynamically, 4k blocks for use by the directory entry table. However, when the disk space is requested from the file system the OS allocates a block equal to the volume block size. Therefore, when the directory entry table makes a request for a new 4k block, what is given in response is a full volume block. For example: if the volume block size were 32k, and the directory entry table needed to grow, it is actually given a 32k block. Then from that 32k block the directory entry table uses it up in 4k blocks. This happens behind the scenes so that the user only sees the 32k block being allocated to the directory entry table.

Given the following statistics from servman, let's see what is being reported:

     Loaded name spaces: DOS, OS2
     Block size: 32 KB
     Directory size (blocks): 30
     Directory entries: 3840
     Used directory entries: 2162

1. 30 total volume blocks / 2 copies of the table = 15 usable blocks

2. 15 volume blocks * 32 KB block size * 1024 (bytes per KB) = 491,520 total bytes allocated

3. 491,520 total bytes allocated / 128 bytes per directory entry = 3,840 total directory entries

4. 3,840 total directory entries / 2 name spaces = 1,920 possible files

5. 2,162 used directory entries / 2 name spaces = 1,081 files currently

If files are deleted the Used directory entries statistic will reflect the change, but the Directory size, and the Directory entries statistic will not change. The directory entry space has been allocated and is never de-allocated. There is, however, a way to reduce the amount of directory entry space. There are three conditions that must be met after the files are deleted:
        1. Purge the volume.
        2. Dismount and mount the volume.
        3. Then, only if an entire volume block was freed up, when the volume mounts that block will not be allocated.

Note: See TID1202046 - "3.x and 4.x Directory Entry Limits" for an in-depth discussion on DET limitations, and other support related issues regarding directory entry tables vs. large volumes..

document

Document Title:	How do you interpret the Directory Entry information in the SERVMAN.NLM utility?
Document ID:	10023642
Solution ID:	1.0.43024554.2444215
Creation Date:	20Dec1999
Modified Date:	31May2001
Novell Product Class:	NetWare

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