IBM Tivoli Storage Manager, Version 7.1

UPDATE DEVCLASS (Update a FILE device class)

Use the FILE device class when you are using files on magnetic disk storage as volumes that store data sequentially (as on tape).

AIX operating systems HP-UX operating systems Linux operating systems Sun Solaris operating systems The FILE device class does not support EXTERNAL libraries.

Windows operating systems The FILE device class does not support EXTERNAL libraries.

AIX operating systems Linux operating systems If you are defining a device class for devices that are to be accessed through a z/OS® media server, see UPDATE DEVCLASS (Update a FILE device class for z/OS media server).

Privilege class

To issue this command, you must have system privilege or unrestricted storage privilege.

Syntax


>>-UPDate DEVclass--device_class_name--------------------------->

>--+-----------------------+--+----------------------+---------->
   '-MOUNTLimit--=--number-'  '-MAXCAPacity--=--size-'   

>--+----------------------------------+------------------------->
   |               .-,--------------. |   
   |               V                | |   
   '-DIRectory--=----directory_name-+-'   

>--+--------------------+--------------------------------------><
   '-SHAREd--=--+-No--+-'   
                '-Yes-'

Parameters

device_class_name (Required)

Specifies the name of the device class to be updated.

MOUNTLimit

Specifies the maximum number of files that can be simultaneously open for input and output. This parameter is optional. You can specify a number from 0 to 4096.

Windows operating systems If the device class is shared with a storage agent (by specifying the SHARED=YES parameter), drives are defined or deleted to match the MOUNTLIMIT value.

If you plan to use the simultaneous-write function, ensure that sufficient drives are available for the write operation. If the number of drives needed for a simultaneous-write operation is greater than the value of the MOUNTLIMIT parameter for a device class, the transaction fails.

MAXCAPacity

Specifies the maximum size of any data storage files that are categorized by this device class. This parameter is optional.

Specify this value as an integer followed by K (kilobytes), M (megabytes), G (gigabytes), or T (terabytes). The minimum size is 1 MB (MAXCAPACITY=1M). If you are defining a FILE device class for database-backup volumes, specify a value for MAXCAPACITY that is appropriate for the size of the database and that minimizes the number of database volumes.

For example, MAXCAPACITY=5G specifies that the maximum capacity for a volume in this device class is 5 gigabytes. The value that is specified must be less than or equal to the maximum supported size of a file on the target file system.

AIX operating systems HP-UX operating systems Linux operating systems Sun Solaris operating systems Do not define a MAXCAPACITY value greater than 640M when this file is for REMOVABLEFILE CD support. A value less than a CD's usable space (650 MB) allows for a one-to-one match between files from the FILE device class and copies that are on CD.

DIRectory

Specifies the directory location or locations of the files that are used in this device class. Enclose the entire list of directories within quotation marks, by using commas to separate individual directory names. Special characters (for example, blank spaces) are allowed within directory names. For example, the directory list "abc def,xyz" contains two directories: abc def and xyz. This parameter is optional.

By specifying a directory name or names, you identify the locations where the server places the files that represent storage volumes for this device class.

AIX operating systems HP-UX operating systems Linux operating systems Sun Solaris operating systems While the command is processed, the server expands the specified directory name or names into their fully qualified forms, starting from the root directory.

Important: If you are using storage agents for shared access to FILE volumes, you must use the DEFINE PATH command to define a path for each storage agent. The path definition includes the directory names that are used by the storage agent to access each directory.

Later, if the server must allocate a scratch volume, it creates a new file in one of these directories. (The server can choose any of the directories in which to create new scratch volumes.) For scratch volumes used to store client data, the file that is created by the server has a file name extension of .bfs. For scratch volumes used to store export data, a file name extension of .exp is used.

AIX operating systems HP-UX operating systems Linux operating systems Sun Solaris operating systems For example, if you define a device class with a directory of tsmstor and the server needs a scratch volume in this device class to store export data, the file that the server creates might be named ⁄tsmstor⁄00566497.exp.

Windows operating systems For example, if you define a device class with a directory of c:\server and the server needs a scratch volume in this device class to store export data, the file that the server creates might be named c:\server\00566497.exp.

Tip: If you specify multiple directories for a device class, ensure that the directories are associated with separate file systems. Space trigger functions and storage pool space calculations take into account the space that remains in each directory. If you specify multiple directories for a device class and the directories are in the same file system, the server calculates space by adding values that represent the space that remains in each directory. These space calculations are inaccurate. Rather than choosing a storage pool with sufficient space for an operation, the server might choose the wrong storage pool and run out of space prematurely. For space triggers, an inaccurate calculation might result in a failure to expand the space available in a storage pool. Failure to expand space in a storage pool is one of the conditions that can cause a trigger to become disabled. If a trigger is disabled because the space in a storage pool was not expanded, you can re-enable the trigger by issuing the following command: update spacetrigger stg. No further changes are required to the space trigger.

Restriction: To modify a list of directories, you must replace the entire list.

SHAREd

Specifies that this FILE device class is shared between the server and one or more storage agents. To prepare for sharing, a library is automatically defined along with a number of drives corresponding to the MOUNTLIMIT associated with the device class. If the library and drives exist and the MOUNTLIMIT is changed, drives can either be created to reach a new higher MOUNTLIMIT value or deleted to reach a new lower value.

Storage agents using FILE volumes

You must ensure that storage agents can access newly created FILE volumes. To access FILE volumes, storage agents replace names from the directory list in the device-class definition with the names in the directory list for the associated path definition. The following illustrates the importance of matching device classes and paths to ensure that storage agents can access newly created FILE volumes.

Suppose you want to use these three directories for a FILE library:

c:\server
d:\server
e:\server

/usr/tivoli1
/usr/tivoli2
/usr/tivoli3

/opt/tivoli1
/opt/tivoli2
/opt/tivoli3

You use the following command to set up a FILE library named CLASSA with one drive named CLASSA1 on SERVER1:

define devclass classa devtype=file 
directory="c:\server,d:\server,e:\server" 
shared=yes mountlimit=1

define devclass classa devtype=file 
directory="/usr/tivoli1,/usr/tivoli2,/usr/tivoli3"
shared=yes mountlimit=1

define devclass classa devtype=file 
directory="/opt/tivoli1,/opt/tivoli2,/opt/tivoli3"
shared=yes mountlimit=1

You want the storage agent STA1 to be able to use the FILE library, so you define the following path for storage agent STA1:
- ```
define path server1 sta1 srctype=server desttype=drive device=file
directory="\\192.168.1.10\c\server,\\192.168.1.10\d\server,
\\192.168.1.10\e\server" library=classa
```
  In this scenario, the storage agent, STA1, replaces the directory name c:\server with the directory name \\192.168.1.10\c\server to access FILE volumes that are in the c:\server directory on the server.
- ```
define path server1 sta1 srctype=server desttype=drive device=file
directory="/usr/ibm1,/usr/ibm2,/usr/ibm3" library=classa
```
  In this scenario, the storage agent, STA1, replaces the directory name /usr/tivoli1 with the directory name /usr/ibm1 to access FILE volumes that are in the /usr/tivoli1 directory on the server.
- ```
define path server1 sta1 srctype=server desttype=drive device=file
directory="/opt/ibm1,/opt/ibm2,/opt/ibm3" library=classa
```
  In this scenario, the storage agent, STA1, replaces the directory name /opt/tivoli1 with the directory name /opt/ibm1/ to access FILE volumes that are in the /opt/tivoli1 directory on the server.

The following results occur:

File volume c:\server\file1.dsm is created by SERVER1. If you later change the first directory for the device class with the following command:
```
update devclass classa directory="c:\otherdir,d:\server,e:\server"
```
SERVER1 is still able to access file volume c:\server\file1.dsm, but the storage agent STA1 is not able to access it because a matching directory name in the PATH directory list no longer exists. If a directory name is not available in the directory list that is associated with the device class, the storage agent can lose access to a FILE volume in that directory. Although the volume is still accessible from the Tivoli® Storage Manager server for reading, failure of the storage agent to access the FILE volume can cause operations to be retried on a LAN-only path or to fail.
If file volume /usr/tivoli1/file1.dsm is created on SERVER1, and if the following command is issued,
```
update devclass classa directory="/usr/otherdir,/usr/tivoli2,
/usr/tivoli3"
```
SERVER1 is still able to access file volume /usr/tivoli1/file1.dsm, but the storage agent STA1 is not able to access it because a matching directory name in the PATH directory list no longer exists. If a directory name is not available in the directory list that is associated with the device class, the storage agent can lose access to a FILE volume in that directory. Although the volume is still accessible from the Tivoli Storage Manager server for reading, failure of the storage agent to access the FILE volume can cause operations to be retried on a LAN-only path or to fail.
If file volume /opt/tivoli1/file1.dsm is created on SERVER1, and if the following command is issued,
```
update devclass classa directory="/opt/otherdir,/opt/tivoli2,
/opt/tivoli3"
```
SERVER1 is still able to access file volume /opt/tivoli1/file1.dsm, but the storage agent STA1 is not able to access it because a matching directory name in the PATH directory list no longer exists. If a directory name is not available in the directory list that is associated with the device class, the storage agent can lose access to a FILE volume in that directory. Although the volume is still accessible from the Tivoli Storage Manager server for reading, failure of the storage agent to access the FILE volume can cause operations to be retried on a LAN-only path or to fail.

Example: Update a FILE device class for sharing

Prepare a FILE device class (named PLAINFILES) for sharing with a Tivoli Storage Manager storage agent.

update devclass plainfiles shared=yes

Example: Update the capacity of a FILE device class

Update a file device class named STORFILES to a maximum capacity of 25 MB.

update devclass storfiles maxcap=25m

Example: Add a directory to a FILE device class

Update the FILE device class, CLASSA, by adding a directory, /usr/otherdir, to the directory list. The directories /opt/tivoli2 and /opt/tivoli3 were specified when the device class was first defined.

update devclass classa 
 directory="/opt/tivoli2,/opt/tivoli3,/usr/otherdir"

Example: Add a directory to a FILE device class

Update the FILE device class, CLASSA, by adding a directory, /usr/otherdir, to the directory list. The directories /usr/tivoli2 and /usr/tivoli3 were specified when the device class was first defined.

update devclass classa 
directory="/usr/tivoli2,/usr/tivoli3,/usr/otherdir"

Example: Add a directory to a FILE device class

Update the FILE device class, CLASSA, by adding a directory, c:\otherdir, to the directory list. The directories d:\server and e:\server were specified when the device class was first defined.

update devclass classa 
 directory="d:\server,e:\server,c:\otherdir"

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