msclass
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Name

msclass — Change the class of service for MSS files

Synopsis

msclass [-R] [-project proj] (1) password options -class cos path ...


(1) [-rpwd read_password] [-wpwd write_password]

Description

The msclass command is used to change or set the class of service information (COS) for MSS files. The class of service information provides user specified hints or other instructions to the MSS on how to manage the file.

Note

Directories do not have class of service information.

Options

msclass specific options:

-p[roject] proj

Supply proj as the project number for charging. Currently, no charging is done for metadata operations, so this option is a placeholder for when charging might be imposed.

-R

Recursively set class of service information. For each operand that names a directory, msclass shall set the specified cos on all MSS files in the hierarchy.

-cl[ass] cos

Supply cos as the new class of service for the MSS files. See Class of Service below for details on the format and contents for cos.

The common password related options are:

-rpwd password

Supply the read password for the following MSS files. If another read password was specified prior to this point in this command line, and the following MSS files do no have a read password, a null password must be given: -rpwd ''. If the MSS files do not have a read password, this option must not be used.

-wpwd password

Supply the write password for the following MSS files. If another write password was specified prior to this point in this command line, and the following MSS files do no have a write password, a null password must be given: -wpwd ''. If the MSS files do not have a write password, this option must not be used.

Operands

path

A pathname of an MSS file whose class of service information is to be modified. If the recursive option (-R) is set, then all MSS files contained within the directory hierarchy named by path will have their class of service modified.

Class of Service

The consistent method to provide class of service information (for all commands that allow you to set it) is with the ­class option. It takes a single string argument of the form:

category1=value1[,category2=value2][,...]

where categoryn specifies the class of service category and the corresponding value is provided by valuen. You may supply values for some or all of the categories in the argument. For the categories for which you do not supply values, either the default value will be used (for newly created MSS files) or the previous value will remain (for existing MSS files). The following table describes the categories and accepted values.

Table 6. Class of Service Descriptions

Category Description
reliability Specifies the desired storage retrieval reliability (that is how much effort to which the MSS will go to make sure the file can be retrieved).
Value Effect
standard DEFAULT

Keep two copies on different pieces of media.
economy Keep a single copy.

Note

Two MSS files differing only by name are not guaranteed to be placed on different media.

Warning

Files stored with more than one copy are still subject to removal or purge. That is, if an MSS file has a class of service that causes multiple copies to be stored is then removed, all copies will be removed. See msrecover(1NCAR) for details on recovering removed or purged files.
usage Provides a hint as to the expected use of the file. Note that the usage values may imply default values for other categories. These defaults may be overridden by explicitly providing values for the other categories.
Value Effect
normal DEFAULT

A file that may be written one or more times, and is expected to be read several times. Implies reliability=standard.

backup A file that is written once, and is rarely read. This file is usually part of a recurring sequence (cyclic period of calendar time) of backup files. Implies reliability=economy.

Note

The purge process behaves differently for files marked with usage=backup. Backup files are permanently deleted from the system on, or shortly after, the file's creation date plus the file's retention period in days. They are not placed into the trash, but are immediately removed (and are not recoverable at that point). See Chapter 5, MSS File Life Cycles and the msrecover(1NCAR) and msretention(1NCAR) documentation for additional discussion.

There is no difference in the behavior when usage=backup files are removed (as with msrm(1NCAR)), that is they will be recoverable for up to 30 days.

Examples

Example 12. Keep one copy of an MSS file.

msclass -class reliability=economy afile

Example 13. Overriding the implied values set by the COS usage category

msclass -class usage=backup,reliability=standard anotherfile

Environment Variables

See Environment Variables section of the Command Behavior and Envrionment chapter for details.

Exit Status

See Exit Status Codes section of the Command Behavior and Environment chapter for details.

See Also

msallinfo(1NCAR), msfind(1NCAR), msls(1NCAR), msrawinfo(1NCAR), msrcp(1NCAR)

Copyright

2006 University Corporation for Atmospheric Research, all rights reserved.

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