Cisco WAN Manager

How To Change the Size of the Cisco WAN Manager Database

Document ID: 9330

Updated: Jan 10, 2006



Cisco WAN Manager (CWM) stores topology information, as well as statistics collected from the nodes, in a database. Depending on certain parameters (size of the network, number of statistics collected, and so on), this database fills up, so the size of the database may need to be increased.

This document describes the methods you can use to increase the size of the CWM database. The first method should be used whenever the physical size of the raw partition has been changed (increased or decreased). The second method explains how to increase the size of the database by the addition of "chunks" to it.



There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

  • CWM versions 9.2, 10.4.x, 10.5.x, 12, and 15

  • Informix 7.2.23 (CWM 9.2), 9.20.UC3 (CWM 10.4 and 10.5), 9.21.UC7XH (CWM 12 and 15)

  • Solaris 5.6 (CWM 9.2), Solaris 5.7 (CWM 10.4 and 10.5), Solaris 8 (CWM 12 and 15)

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.


For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Add Chunks to the Database

A chunk is a block of disk space that is used to increase the size of the database. This can be either a flat file (UNIX file) or an unmounted raw partition (part of the disk with no UNIX file system).

Addition of a chunk to the CWM database allows you to increase the size of the database without the need to resize the original raw partition. A chunk can be another raw partition or a flat file (one that sits on a standard UNIX filesystem).

As root, issue this command to add a chunk:

onspaces -a rootdbs -p (device/name) -s (size in KBytes) -o (offset in KBytes)

Note: You can also add chunks with the menu-driven onmonitor application.

Add a Raw Partition

When you add the raw partition as the seventh slice on disk 1 of your system with a size of 1.9 Gb (1,900,000 KB), you must issue this command:

# onspaces -a rootdbs -p /dev/rdsk/c0t1d0s7 -s 1900000 -o 200

The offset indicates where the data is stored. On some systems, the disk information is written at the beginning of the disk. With the offset, you can make sure not to write over such important data. Refer to the Informix documentation (the administrator's guide for 7.2 or 9.2 for the proper offset to use with your system.

Add a Flat File

If you have no raw partition available, you can add a flat file. In this case, the structure of the database is implemented over the UNIX filesystem. Performance may be impacted.

Assume that you need to add a 100 MB flat file (100,000 KB). You must create the file and give it the appropriate privileges and ownership.

As root, issue these commands:

# touch /usr/users/informix/flat_file 
# chmod 660 /usr/users/informix/flat_file 
# chown informix:informix /usr/users/informix/flat_file

Once the file is created, you can issue this command to add it as a chunk:

# /usr/users/informix/bin/onspaces -a rootdbs -p /usr/users/informix/flat_file -s 100000 -o 0

In this case, the offset can be 0, but you may specify another value. If you want to use this flat file as two chunks of 50 MB, you can run onspaces two times: the first time with an offset of 0, the second time with an offset of 50000. Issue these commands:

# /usr/users/informix/bin/onspaces -a rootdbs -p /usr/users/informix/flat_file -s 50000 -o 0 
# /usr/users/informix/bin/onspaces -a rootdbs -p /usr/users/informix/falt_file -s 50000 -o 50000

Two more chunks are added to the database.

You can receive an error message like this while you run onspaces:

GLS initialization failed, error -23101

If so, you must issue this command as root:

source ~svplus/.cshrc

You must run the cshell as root to set the environment correctly.

Here is an example of a flat file that gets added as a chunk:

root@master 21 % touch /usr/users/informix/flat_file
root@master 22 % chmod 660 /usr/users/informix/flat_file
root@master 23 % chown informix:informix /usr/users/informix/flat_file
root@master 24 % onspaces -a rootdbs -p /usr/users/informix/flat_file -s 100000 -o 0
Verifying physical disk space, please wait ... 
Chunk successfully added.

Check the Database Usage

In order to check the current status of the database, issue the onstat -d command as user svplus. Among other things, this command output gives you the number of free pages.

root@master 25 % onstat -d
Informix Dynamic Server 2000 Version 9.20.UC3   -- On-Line -- Up 23 days
21:48:58 -- 108544 Kbytes
address number flags    fchunk nchunks flags owner     name
14ed17d0     1     1         1       2     N informix  rootdbs
 1 active, 2047 maximum 
address chk/dbs offset size    free   bpages flags   pathname
14ed1918  1   1      0 612264  226253           PO-  /dev/rdsk/c0t0d0s7
1553feb0  2   1      0 50000   49997            PO- 
 2 active, 2047 maximum

Note: The size given by this command is in blocks (2 KB).

Remove a Chunk

A chunk can also be removed from the database. Issue the onspaces command with these parameters:

# onspaces -d rootdbs -p chunk -o offset

The offset should precisely match the one configured at chunk creation. Here is an example of a chunk that gets removed:

root@master 21 % onspaces -d rootdbs -p /usr/users/informix/flat_file -o 0
WARNING: Dropping a chunk. 
Do you really want to continue? (y/n)y 
Chunk successfully dropped. 
** WARNING ** A level 0 archive for DBspace rootdbs will need to be done before 
'/usr/users/informix/flat_file' can be reused (see Dynamic Server 2000 
Administrator's manual). 
root@master 22 %

Related Information

Updated: Jan 10, 2006
Document ID: 9330