mkpool

Creates a VOB storage pool or modifies its scrubbing parameters

APPLICABILITY

ClearCase (cleartool subcommand), Attache (command)

SYNOPSIS

• Create source pool:

  mkpool -sou·rce

  
  

  [ -c·omment comment | -cfi·le comment-file-pname |-cq·uery | -cqe·ach | -nc·omment ]
  pool-selector ...

• Create derived object pool or cleartext pool:

  mkpool { -der·ived | -cle·artext }

  
  

  [ -siz·e max-kbytes reclaim-kbytes [ -age hours ] [ -ale·rt command ] ]
  [ -c·omment comment | -cfi·le comment-file-pname |-cq·uery | -cqe·ach | -nc·omment ]
  pool-selector ...

• Update pool parameters:

  mkpool -upd·ate [ -siz·e max-kbytes reclaim-kbytes ] [ -age hours ] [ -ale·rt command ]

  
  

  [ -c·omment comment | -cfi·le comment-file-pname |-cq·uery | -cqe·ach | -nc·omment ]
  pool-selector ...

DESCRIPTION

The mkpool command creates a source storage pool, derived object storage pool, or cleartext storage pool, and initializes the pool's scrubbing parameters. You can also use this command to update the scrubbing parameters of an existing storage pool.

Storage pools are directories used as physical storage areas for different kinds of ClearCase data:

• A source storage pool stores the data containers that contain versions of elements.
• A derived object storage pool stores shared derived objects-those that are referenced by more than one view.
• A cleartext storage pool is a cache of text files. If an element's versions are stored in a compressed format, accessing a particular version involves some processing overhead; a type manager program is invoked to extract the cleartext of that version from the data container. As a performance optimization, ClearCase "caches" the extracted version as a file in a cleartext storage pool. The next access to that same version uses the cached copy, saving the cost of extracting the version from the data container again.

Creating a new VOB with the mkvob command creates one default pool of each kind: sdft (source pool), ddft (derived object pool), and cdft (cleartext pool).

mkpool creates a storage pool as a directory within the VOB storage area. Source pools are always created within subdirectory s of the VOB storage directory; derived object pools are created within subdirectory d; cleartext pools are created within subdirectory c.

Pool Allocation and Inheritance

Each file element is assigned to one source pool and one cleartext pool. The source pool provides permanent storage, in one or more data container files, for all of the element's versions. If the element's versions are stored in a compressed format, the cleartext pool is used to cache extracted versions of that element, as described earlier. (If each version is stored uncompressed in a separate data container, the cleartext pool is not used.)

Each directory element is also assigned to one source pool and one cleartext pool. But directory versions themselves are not stored in these pools. (They are stored directly in the VOB database.) Rather, a directory's pool assignments are used solely for pool inheritance: each element created within the directory inherits its source and cleartext pool assignments.

Each directory element is also assigned to one derived object pool. All shared derived objects with pathnames in that directory are stored in that pool. A new directory element inherits the derived object pool of its parent, along with the source and cleartext pools.

The pool inheritance scheme begins at the VOB root directory (top-level directory element) created by mkvob, which is automatically assigned to the default pools.

You can change any of an element's pool assignments with the chpool command.

Scrubbing

Scrubbing is the process of reclaiming space in a derived object pool or cleartext pool. (Source pools are not subject to scrubbing.) This process is performed by the scrubber utility. mkpool initializes or updates these scrubbing parameters:

The default settings for the scrubbing parameters are max-kbytes = 0, reclaim-kbytes = 0, hours = 96. See the scrubber reference page for details on how these parameters are interpreted.

By default, the ClearCase scheduler runs scrubber periodically. See the schedule reference page for information on describing and changing scheduled jobs.

Getting Information on Storage Pools

The lspool command lists a VOB's storage pools. If you include the -long option, the current settings of the scrubbing parameters are listed, as well. (The describe -pool command displays the same information as lspool -long.)

PERMISSIONS AND LOCKS

Permissions Checking: For each object processed, you must be one of the following: VOB owner, member of the ClearCase group. See the permissions reference page.

Locks: An error occurs if any of the following objects are locked: VOB, pool (for -update only).

OPTIONS AND ARGUMENTS

SPECIFYING THE KIND OF STORAGE POOL / SPECIFYING AN UPDATE.  Default: You must specify the kind of pool, unless you use -update and name an existing pool. The following options are mutually exclusive.

-sou·rce

Creates a source pool.

-der·ived

Creates a derived object pool.

-cle·artext

Creates a cleartext pool.

-upd·ate

Asserts that the parameters of an existing pool are to be updated. You must also use a -size and/or -age option.

SPECIFYING NEW PARAMETERS.  Default: For a new derived object or cleartext pool: the maximum size and reclaim size parameters are set to 0, which enables a special scrubbing procedure. (See the scrubber reference page.) The age parameter is set to 96 (hours). These parameters are meaningless for a source pool.

When updating an existing pool, you must use at least one of -size and -age.

-siz·e max-kbytes reclaim-kbytes

Specifies that the pool is scrubbed if its size exceeds max-kbytes KB; scrubbing will continues until the pool reaches the goal size of reclaim-kbytes KB.

-age hours

Prevents scrubbing of derived objects or cleartext files that have been referenced within the specified number of hours. Specifying -age 0 restores the default age setting (96 hours).

SCRUBBER FAILURE PROCESSING.  Default: If scrubber fails to scrub a pool below its max-kbytes level, it logs a warning message in the event log, but takes no other action.

-ale·rt command

Causes scrubber to run the specified command (typically, a batch file) whenever it fails to scrub a pool below its max-kbytes level. If you invoke a command built in to the Windows shell (for example, cd, del, dir, or copy) instead of a batch file, you must invoke the shell with cmd /c. For example:

-alert 'cmd /c cd \tmp & del *.*'

EVENT RECORDS AND COMMENTS. Default: Creates one or more event records, with commenting controlled by your .clearcase_profile file (default: -cqe). See CUSTOMIZING COMMENT HANDLING in the comments reference page. Comments can be edited with chevent.

-c·omment comment | -cfi·le comment-file-pname |-cq·uery | -cqe·ach | -nc·omment

Overrides the default with the option you specify. See the comments reference page.

SPECIFYING THE POOL.  Default: Creates or updates a pool in the VOB containing the current working directory unless you specify another VOB with the @vob-selector suffix.

pool-selector ...

One or more names for the storage pools to be created. Specify pool-selector in the form [pool:]pool-name[@vob-selector]

EXAMPLES

Examples including wildcards or quoting are written for use in cleartool interactive mode. If you use cleartool single-command mode, you may need to change the wildcards and quoting to make your command interpreter process the command appropriately.

In cleartool single-command mode, cmd-context represents the command interpreter prompt. In cleartool interactive mode, cmd-context represents the interactive cleartool prompt. In Attache, cmd-context represents the workspace prompt.

• Create a source pool that uses the default pool parameters.

cmd-context mkpool -source -c "pool for c source files" c_pool

Created pool "c_pool".

• Create a derived object pool with a maximum size of 10,000 KB (10 MB) and a reclaim size of 8,000 KB (8 MB). Allow the age parameter to assume its default value.

cmd-context mkpool -derived -nc -size 10000 8000 do1

Created pool "do1".

• Update the derived object pool created in the previous example, so that any derived object referenced within the last week (168 hours) is not scrubbed.

cmd-context mkpool -nc -update -age 168 do1

Updated pool "do1".

• Create a cleartext pool named my_ctpool that uses the default pool parameters. Then, change all elements using pool cdft (the default cleartext pool) to use my_ctpool instead.

cmd-context mkpool -cleartext -c "alternate cleartext pool" my_ctpool

Created pool "my_ctpool".

cmd-context find . -all -element 'pool(cdft)' -exec 'cleartool chpool ^
-force my_ctpool $CLEARCASE_PN'

Changed pool for "\users_hw" to "my_ctpool".
Changed pool for "\users_hw\bin" to "my_ctpool".
Changed pool for "\users_hw\bin\hello" to "my_ctpool".
Changed pool for "\users_hw\bugs" to "my_ctpool".
Changed pool for "\users_hw\bugs\bug.report.21" to "my_ctpool".
Changed pool for "\users_hw\doc" to "my_ctpool".
Changed pool for "\users_hw\doc\util.doc" to "my_ctpool".
Changed pool for "\users_hw\include" to "my_ctpool".
Changed pool for "\users_hw\libs" to "my_ctpool".
Changed pool for "\users_hw\libs\libntx.a" to "my_ctpool".
Changed pool for "\users_hw\libs\libpvt.a" to "my_ctpool"
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SEE ALSO

chpool, find, lspool, mkvob, schedule, scrubber