Console Commands in NetWare 5.1: VMDISMOUNT, VMMOUNT, VMVOLUMES, VOLUME

Articles and Tips: article

Kevin Burnett
Senior Research Engineer
Novell AppNotes

01 Feb 2002

This section is the last in a series that describes each of the NetWare 5.1 console commands (both normal and hidden) in alphabetical order and explains when, why, and how to use them properly. To see a list of the commands that you can perform at the sever console, type HELP <Enter> at the server console prompt. To use the commands described here, simply type the command at the server console prompt followed by the <Enter> key.

VMDISMOUNT

The VMDISMOUNT console command dismounts a NetWare volume and makes the volume unavailable to users, thereby allowing volume maintenance or repairs while the server is up. This can be handy in server environments that are using hot-swap disk technology.

In this scenario, if one of the hard disks that make up a logical NetWare volume goes bad, the volume can be shut down. The faulty disk can then be replaced. The volume can be recreated and brought back on-line. All of this can happen without shutting down power to the server and without disrupting users who are using the remaining volumes on the server.

NetWare volumes can be referred to by either their name or number. You can discover either of these items by typing the VMVOLUME console command on the NetWare server console screen. (For more information about the VMVOLUME console command, see VMVOLUME, below.)

Usage for the VMDISMOUNT command is:


VMDISMOUNT 
VolumeName
 or 
VolumeNumber

Examples would be:


vmdismount sys or vmdismount 0

VMMOUNT

The opposite of VMDISMOUNT, the VMMOUNT command makes a volume available to users. The VMMOUNT command can mount a NetWare logical volume by either specifying the volume name or the volume number.

Usage is as follows:

VMMOUNT VolumeName or VolumeNumber

Examples would be:

vmmount sys or vmmount 0

VMVOLUMES

VMVOLUMES displays a list of currently mounted volumes on a NetWare 5.1 server. This information includes volume number, status, and name. A typical result from executing this console command would look like:


<Server Name> : vmvolumes
Volume Information
Number                        Status                           Name
0                        MOUNTED                           SYS
1                        MOUNTED                           ADMIN
2                        MOUNTED                           BIG

Usage is as follows:


vmvolumes

VOLUME

This console command can be used at the server console to list mounted volumes. It can also be used to give detailed information about a specified volume. The VOLUME command has an optional command-line parameter, which allows you to specify the name of a volume on your NetWare server. The syntax is as follows:


VOLUME [
name
]

These parameters are summarized in the following table:

Parameter	Use
(no parameter)	Lists general information about all mounted volumes.
Name	Specifies the volume you want to display information about.

When you execute the VOLUME command without the name parameter, a message similar to the following appears on the server's console:

<Server Name> : Volume
Mounted Volumes                  Name Spaces                       Flags
SYS                  DOS, MAC, NFS, LONG                       Cp Sa
_ADMIN                  DOS, MAC, NFS, LONG                       NSS P
BIG                  DOS, MAC, NFS, LONG                       NSS

The output lists each mounted volume's name, its name spaces, and the flags that are set for that volume.

The possible flags are:

Flag	Description
Cp	Indicates that file compression is enabled on the volume
Sa	Indicates that block suballocation is enabled on the volume
Mg	Indicates that migration is enabled on the volume
NSS	Indicates that the volume is an NSS-enabled volume
NSS P	In NSS, the _ADMIN volume is a read-only volume that is automatically created when a storage group and NSS volume are created. This volume contains a dynamic list of objects that NSS uses, and it cannot be deleted. The flag 'P' indicates that the volume can not be deleted.

When you execute VOLUME name , the screen displays more detailed information about the specific volume, such as the following:

<Server Name> : Volume SYS

Block Usage: 38 FAT blocks, 834 Directories blocks, 32 EDS blocks
Blocks: 134897 used of 150896 Directory Entries: 75837 used of 213504
EDS: 56 used of 512 extants Extended Attributes: 11
Data Streams: 11594, 23294 (Cp), 2 (Cp Limbo), 7896 (Cant Cp)
Sub Alloc Blocks: 3599
NameSpaces: DOS, LONG
Cp Sa

Let's look at this output a little bit closer. Each element of the volume information is listed in the following table with a description of the element.

Element	Description
Block Usage: 38 FAT blocks, 834 Directory blocks, 32 EDS blocks	A block is the smallest amount of disk space that the server reads or writes at a time. All disk accesses are measured in blocks. The block size for a traditional NetWare volume is defined at installation, and is usually between 4 KB and 64 KB. With NSS, the block size is currently set at 4 KB. The File Allocation Table (FAT) is an index table that points to the disk areas where files are located. Every volume contains a FAT. Directory blocks: Every directory is the parent to a linked list of one or more 4-KB directory blocks. When a directory is created, a new 4-KB block is allocated and becomes the first block. As needed, other directory blocks will be allocated and linked in the list belonging to the parent. The linked list of blocks contains the directory entry information for files residing in the directory. Additionally, directory trustee assignments will be located in these blocks. EDS blocks: EDS stands for Extended Directory Space. They contain extended attributes, file names longer than around 100 bytes, Macintosh comment information, and other types of metadata for a file. The EDS area of the volume is measured in blocks that are 128 bytes in size; some of the blocks are free and some of the blocks are in use. The EDS blocks are allocated from the normal volume blocks; one volume block will hold a lot of EDS blocks.
Blocks: 134897 used of 150896	The actual amount of disk blocks in use compared to the maximum available amount.
Directory Entries: 75837 used of 213504	The number of physical directory entries out of the maximum supported by the volume. The number of directory entries a volume supports is determined mostly by the volume's size.
EDS: 56 used of 512 extants	Specifies the number of extended directory space entries (128 bytes each) that are available on the volume. In this case, there are 56 EDS entries used out of 512 that currently exist.
Extended Attributes: 11	Extended Attributes are a type of file metadata defined by Microsoft. There is a common client API that allows a client application to write whatever it wants into a file's Extended Attribute--within a few constraints. For more information on this, see the Novell Client SDK at http://developer.novell.com .
Data Streams: 11594, 23294 (Cp), 2 (Cp Limbo), 7896 (Cant Cp)	Data Streams: This refers to a FAT chain associated with a file. A data stream is the data you actually read from and write to when you open a file. DOS and Windows NT files have 1 data stream (except for 0-byte length files). Macintosh files may have 2 data streams: a data fork and a resource fork. In this case, there are 11594 Data Streams, 23294 compressed Data Streams, 2 compressed limbo Data Streams and 7896 Data Streams that cannot be compressed.
Sub Alloc Blocks: 3599	This has to do with block suballocation, which is the division of partially used disk blocks into smaller, 512-byte blocks. Block suballocation allows the last part of several files to share one disk block rather than using one disk block for each file, thereby using disk space more efficiently. The number of suballocation blocks in use is shown.
NameSpaces: DOS, LONG	This entry indicates which name space (DOS is the default) are supported natively on NetWare server. Name spaces allows files to appear in native mode to users at different types of workstations. In this case, the DOS namespace and LONG file name namespaces are supported.
Cp Sa	Volume Flags: Cp indicates that file compression is enabled on the volume. Sa indicates that block suballocation is enabled on the volume.

The four console commands that we have discussed in this column are summarized in the following table:

Console Command	Function	Example
VMDISMOUNT VolumeName VMDISMOUNT VolumeNumber	Allows volume maintenance or repairs while the file server is up by making the volume unavailable to users	Vmdismount sys Vmdismount 0
VMMOUNT VolumeName VMMOUNT VolumeNumber	Makes a volume available to users	Vmmount sys Vmmount 0
VMVOLUMES	Displays a list of currently mounted volumes including number, status, and name	Vmvolumes
VOLUME VOLUME [name]	Displays a list of currently mounted volumes or the information about a specific volume	Volume Volume sys

* Originally published in Novell AppNotes

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The origin of this information may be internal or external to Novell. While Novell makes all reasonable efforts to verify this information, Novell does not make explicit or implied claims to its validity.