Description

policy (type of object)

When set to on, dmfsmon will free dual-state files before freeing files it will have to migrate first. The default is off.

Percentage of file system space by which dmfsmon will decrement FREE_SPACE_MINIMUM if it cannot find enough files to migrate so that the value is reached. The decrement is applied until a value is found that dmfsmon can achieve. If space later frees up, the FREE_SPACE_MINIMUM is reset to its original value. Valid values are between 1 and the value of FREE_SPACE_TARGET. The default is 2.

Minimum percentage of free file system space that dmfsmon maintains. dmfsmon will begin to migrate files when the available free space for the file system falls below this percentage value. This parameter is required; there is no default.

Percentage of free file system space that dmfsmon will try to achieve if free space reaches or falls below FREE_SPACE_MINIMUM. This parameter is required; there is no default.

Percentage of file system capacity that DMF maintains as a reserve of dual-state files whose online space can be freed if free space reaches or falls below FREE_SPACE_MINIMUM. dmfsmon tries to make sure that this percentage of the file system is migrated, migrating, or free after it runs to make space available. This parameter is required; there is no default.

Description

Specifies a floating point constant and floating point multiplier to use to calculate the weight given to a file's age. AGE_WEIGHT is calculated as constant + (multiplier * file_age_in_days). If DMF cannot locate values for this parameter, it uses a floating point constant of 1 and a floating point multiplier of 1.

Specifies a floating point constant and floating point multiplier to use to calculate the weight given to a file's size. SPACE_WEIGHT is calculated as constant + (multiplier * file_disk_space_in_bytes). If DMF cannot locate values for this parameter, it uses a floating point constant of 0 and a floating point multiplier of 0.

Description

Specifies the MSP(s)/VG(s) to use for a file. You can list as many MSP/VG names as you have MSP/VG objects defined. A copy of the file will be migrated to each MSP/VG listed. The special MSP/VG name none means that the file will not be migrated. If you define more than one MSP/VG, separate the names with white space. As a convenience, you can use SELECT_VG instead of SELECT_MSP, and the object can contain a mixture of both forms. If no SELECT_MSP(or SELECT_VG ) parameter applies to a file, it will not be migrated. The parameters are processed in the order they appear in the policy. There is no default.

Description

Days since last modification or last access of the file, whichever is more recent

Number of bytes the file occupies on disk (always a multiple of the blocksize, which may be larger or smaller than the length of the file)

Group ID of one or more files

User ID of one or more files

Description

msp (type of object)

Directory in which the MSP stores chunks while merging them from sparse tapes. If you do not specify this parameter, DMF uses the value of TMP_DIR from the base object.

Amount of disk space (in bytes) that dmatmsp can use when merging chunks from sparse tapes. During merging, small chunks from sparse tapes are cached on disk before being written to a tape. The default is 0, which causes all files to be merged via sockets. For more information, see Step 5.

Maximum number of child processes the MSP is allowed to fork. The maximum value is 100; the default is 4.

Binary file to execute in order to initiate this MSP. For the tape MSP, this value must be dmatmsp.

Transfer size (in bytes) used when reading from or writing to files within a DMF file system. The value must be between 4096 and 16 million (16m). The default is 65536.

Minimum number of seconds that a tape no longer containing valid data must remain unused before the MSP overwrites it. The default value is 172,800 seconds (2 days), and the minimum allowed value is 0.

When an MSP removes all data from a tape, it sets the hfree (hold free tape) flag bit in the tape's volume (VOL) database entry to prevent that tape from being immediately reused. The next time the MSP scans the database for volumes after HFREE_TIME seconds have passed, the MSP clears the hfree flag, allowing the tape to be rewritten. If HFREE_TIME is set to 0, the MSP will never clear hfree, so an unused tape will not be reused until you clear its hfree flag manually. For a description of how to set and clear the hfree flag manually, see the dmvoladm man page.

Largest chunk (in bytes) that will be merged using the merge disk cache. Larger files are transferred directly via a socket from the read child to the write child. The default is 25% of the CACHE_SPACE value. Valid values are 0 through the value of CACHE_SPACE.

Specifies that the MSP should break up large files into chunks no larger than this value (specified in bytes) as it writes data to tape. If a file is larger than this size, it is broken up into pieces of the specified size, and, depending on other activity, more than one write child may be used to write the data to tape. If MAX_CHUNK_SIZE is 0 (the default) the MSP only breaks a file into chunks when an end of volume is reached.

Maximum number of write child processes the MSP will schedule. The default and the maximum are the value of CHILD_MAXIMUM; the minimum is 1.

Limit at which the MSP stops scheduling tapes for merging. This number refers to the sum of the active and queued children generated from gets, puts, and merges. The default is CHILD_MAXIMUM, which means that if sparse tapes are available, children will be created until there are CHILD_MAXIMUM children, thus using tape efficiently. However, if any recall requests arrive, they will be started before new merges.

Setting this number below CHILD_MAXIMUM reserves some tape units for recalls at the expense of merge efficiency. Setting this number above CHILD_MAXIMUM increases the priority of merges relative to recalls.

Highest message level number that will be written to the MSP log. It must be an integer between 0 and 6; the higher the number, the more messages written to the log file. The default is 2. For more information on message levels, see “General Message Log File Format”.

Minimum number of unused tapes that can exist in the MSP VOL database before operator notification. If the number of unused tapes falls below MIN_TAPES, the operator will be asked to add new tapes. The default is 10; the minimum is 0.

Specifies the name of a device object that describes how the tapes are accessed and used. There is no default. The device object is described in “Device Objects”.

Names the task groups that contain tasks the MSP should run. They are configured as objects of TYPE taskgroup. There is no default. See “Configuring Tape Maintenance Tasks ”, for more information.

Minutes after which the MSP will flush files to tape. The default is 120 minutes.

Description

device (type of object)

Block size used when writing tapes from the beginning. The default depends upon the device, with DMF setting defaults as follows:

AMPEX DIS/DST       1199840
DLT                 131072
STK 9840            126976
Other devices       65536

Label type used when writing tapes from the beginning. Possible values are nl (no label), sl (standard label, for IBM tapes), and al (ANSI label). The default is al.

Specifies the mounting service to use. Supported values are openvault and tmf. This parameter is required; there is no default.

Specifies the number of seconds that all devices in the object can be down before an e-mail message is sent to the administrator and an error message is logged. The default is 0, which means that as soon as DMF notices that the mounting service is up and all of the drives are configured down, it will e-mail a message.

Specifies how the tape should be positioned to a zone; either skip or direct. skip specifies the use of tape mark skipping. direct specifies the use of block ID seek capability if the block ID is known. The default is direct.

Level of retry in the event of a failure during zone positioning; one of none, lazy, or aggressive. lazy specifies that the MSP will retry if a reasonably fast alternative method of positioning is available. aggressive specifies that the MSP may try more costly and time-consuming alternatives. If the MSP is unable to position to a zone, the MSP aborts all recalls for files with data in that zone (however, DMF does not abort them if a copy exists in another MSP). The default is lazy.

Specifies whether the tape MSP write child should (prior to writing) verify that the tape is correctly positioned and that the tape was properly terminated by the last use. The default is to verify. Specifying no or off turns verification off; anything else ensures verification.

Specifies that tape block should be checksummed before writing. If a tape block has a checksum, it is verified when read. The default is on.

Specifies approximately how much data the write child should put in a zone. The write child adds files and chunks to a zone until the data written equals or exceeds this value, at which time it writes a tape mark and updates the database. Smaller values allow faster recalls and better recoverability but poorer write performance. The MSP also uses zone size to determine when to start write children. The default is 50 MB.

Description

libraryserver (type of object)

Directory in which the VG stores chunks while merging them from sparse tapes. If you do not specify this parameter, DMF uses the value of TMP_DIR from the base object.

Amount of disk space (in bytes) that dmatls can use when merging chunks from sparse tapes. During merging, small chunks from sparse tapes are cached on disk before being written to a tape. The default is 0, which causes all files to be merged via sockets.

Binary file to execute to initiate the LS. This value must be dmatls.

Names one or more drive groups containing drives that the LS can use for mounting and unmounting volumes. They are configured as objects of type drivegroup. This parameter must be configured. There is no default.

The order of the values specified for this parameter is integral to the determination of the MSP or volume group from which the DMF daemon attempts to recall an offline file. If the offline file has more than one copy, DMF uses a specific order when it attempts to recall the file. It searches for a good copy of the offline file in MSP or Library Server order, from the dmdaemon object's MSP_NAMES or LS_NAMES parameter. If one of those names refers to a Library Server, it searches for the copy in drive group order, from the Library Server object's DRIVE_GROUPS parameter. It then searches for the copy in volume group order from the drivegroup object's VOLUME_GROUPS parameter.

Largest chunk (in bytes) that will be merged using the merge disk cache. Larger files are transferred directly via a socket from the read child to the write child. The default is 25% of the CACHE_SPACE value. Valid values are 0 through the value of CACHE_SPACE.

Highest message level number that will be written to the LS log, which includes messages from from the LS's components. It must be an integer between 0 and 6; the higher the number, the more messages written to the log file. The default is 2.

See “Configuring Automated Maintenance Tasks”.

Names the task groups that contain tasks the LS should run. They are configured as objects of TYPE taskgroup. There is no default.

Names the resource watcher that the LS should run. They can be configured as objects of type resourcewatcher, but if the default parameters are acceptable, there is no need to do this. The default is no watcher.

Description

drivegroup (type of object)

Block size used when writing tapes from the beginning. The default depends upon the device, with DMF setting defaults as follows:

AMPEX DIS/DST       1199840
DLT                 131072
STK 9840            126976
Other devices       65536

Transfer size (in bytes) used when reading from or writing to files within a DMF file system. The value must be between 4096 and 16 million (16m). The default is 65536.

Maximum number of drives within this drive group that the LS is allowed to attempt to use simultaneously. This can be more or less than the number of drives the LS can physically detect. The maximum is 100; the default is 100 for Drive Groups. If a negative value is specified for DRIVE_MAXIMUM, the Drive Group uses the sum of the number of available drives and DRIVE_MAXIMUM.

Names the resource scheduler that the DG should run for the scheduling of tape drives. They are configured as objects of type resourcescheduler. The default is a resource scheduler of default type and parameters. For the defaults, see “Resource Scheduler Objects”.

An integer value that controls the number of "bad" drives the drive group is allowed to try to configure down. When more than this number are down, whether due to the DG or to external influences such as the system administrator, the DG does not attempt to disable any more. The default of 0 prevents the DG from disabling any.

Label type used when writing tapes from the beginning. Possible values are nl (no label), sl (standard label, for IBM tapes), and al (ANSI label). The default is al.

Specifies the maximum number of times DMF can attempt to restart the mounting service (TMF or OpenVault) without requiring administrator intervention. The default and recommended values are 1 for TMF and 0 for OpenVault.

Specifies the mounting service to use. Possible values are openvault and tmf. The default is openvault.

Specifies the name by which the drive group's devices are known to the mounting service. In the case of TMF, this is the device group name that would be used with the -g option on the tmmnt command. For OpenVault, this is the drive group name that is specified by the ov_drivegroup command.

Specifies the maximum number of minutes to wait for a tape to be mounted. Default is zero, which means forever.

If a tape mount request waits for longer than this period of time, the DG attempts to stop and restart the mount service, in an attempt to force the hanging subsystem to resume normal operation, or to fail solidly.

Do not make this value too restrictive, as any non-LS tape activity (including MSPs and xfsdump) can legitimately delay a VG's tape mount, which could result in this timeout being exceeded.

Specifies the number of seconds that all drives in the drive group can be down before an e-mail message is sent to the administrator and an error message is logged. The default is 0, which means that as soon as DMF notices that the mounting service is up and all of the drives are configured down, it will e-mail a message.

Specifies a list of access mode names that control how data is written to tape. The default value is readwrite when migrating and readonly when recalling. This parameter is optional.

Specifies a list of names to be provided to OpenVault for the firstmount clause when mounting a tape. Use compression to request compression. By default, this list is empty.

Specifies how the tape should be positioned. The values can be skip, direct, or data. skip means to use tape mark skipping to the zone. direct means to use block ID seek capability to the zone if the block ID is known. data means the same as direct when the tape is being written. When the tape is being read, data means that the read child will try to determine the block ID of the data being read, and use the block ID seek capability to position there. The default depends on the type of drive, and is either direct or data. If data positioning is specified for a drive whose default is direct, the block ID is calculated by adding an estimate of the number of blocks from the start of the zone to the data being recalled and the block ID of the start of the zone. Not all drives use this format for block ID.

Specifies the level of retry in the event of a failure during zone positioning. The values can be none, lazy, or aggressive. With lazy, the VG retries if a reasonably fast alternative means of positioning is available. With aggressive, the VG can try more costly and time consuming alternatives. If the VG is unable to position to a zone, all recalls for files with data in that zone are aborted by the VG (though not by DMF if a copy exists in another VG). The default is lazy, to give the best overall recall time. If you are having trouble getting data from tape, you might want to try aggressive.

Specifies the number of minutes after which a drive that was configured down by the DG will be automatically reinstated and made available for use again. Zero means it should be left disabled indefinitely. The default is 1440 (one day).

Specifies the number of minutes after which a volume that had its HLOCK flag set by DMF will be automatically reinstated and made available for use again. Zero means they should be left disabled indefinitely. The default is 1440 (one day).

See “Configuring Automated Maintenance Tasks”.

Names the task groups that contain tasks the DG should run. They are configured as objects of TYPE taskgroup. There is no default.

Specifies command options that should be added to the tmmnt command when mounting a tape. DMF uses the -Z option to tmmnt to ignore options controlling block size and label parameters. Use the BLOCK_SIZE and LABEL_TYPE device parameters instead. Unlike a tape MSP, there is no need for a -g option here. If it is provided, it must match the value of the MOUNT_SERVICE_GROUP parameter. To request compression, use -i. Options that are ignored are -a, -b, -c, -D, -f, -F, -l, -L, -n, -o, -O, -p, -P, -q, -R, -t, -T, -U, -v, -V, -w, -x , and -X.

Specifies whether the LS write child should (prior to writing) verify that the tape is correctly positioned and that the tape was properly terminated by the last use. The default is to verify. Specifying no or off turns verification off; anything else ensures verification.

Names the volume group(s) containing volumes that can be mounted on any of the drives within this drive group. They are configured as objects of type volumegroup. This parameter must be configured. There is no default.

The order of the values specified for this parameter is integral to the determination of the MSP or volume group from which the DMF daemon attempts to recall an offline file. If the offline file has more than one copy, DMF uses a specific order when it attempts to recall the file. It searches for a good copy of the offline file in MSP or Library Server order, from the dmdaemon object's MSP_NAMES or LS_NAMES parameter. If one of those names refers to a Library Server, it searches for the copy in drive group order, from the Library Server object's DRIVE_GROUPS parameter. It then searches for the copy in volume group order from the drivegroup object's VOLUME_GROUPS parameter.

Specifies that tape block should be checksummed before writing. If a tape block has a checksum, it is verified when read. The default is on.

Description

volumegroup (type of object)

Name of an allocation group that serves as a source of additional volumes if a volume group runs out of media. Normally, one allocation group is configured to serve multiple volume groups. As a volume's hfree flag is cleared (see HFREE_TIME below) in a volume group, it is immediately returned to the allocation group subject to the restrictions imposed by the configuration parameters ALLOCATION_MAXIMUM and ALLOCATION_MINIMUM. The administrator must ensure that volumes in the allocation group are mountable on drives in the same drive group as any volume group that references the allocation group. It is an error to assign an ALLOCATION_GROUP name that is the same as an existing volume group name. The ALLOCATION_GROUP defines a logical pool of volumes rather than an actual operational volume group.

As allocation groups have no configurable parameters, they have no configuration stanzas of their own; a reference to them in a volume group's ALLOCATION_GROUP parameter is all that is needed to activate them. A volume group that does not define ALLOCATION_GROUP will not use one.

Maximum size in number of volumes to which a volume group can grow by borrowing volumes from its allocation group. The minimum value is zero, the maximum is infinity, and the default is infinity. If the volume group already contains ALLOCATION_MAXIMUM or more volumes, no additional volumes are borrowed from the allocation group. If no allocation group is defined, this parameter is meaningless.

Minimum size in number of volumes to which a volume group can shrink by returning volumes to its allocation group. The minimum value is zero, which is the default, and the maximum is the current value of ALLOCATION_MAXIMUM. If the volume group already contains ALLOCATION_MINIMUM or fewer volumes, no additional volumes are returned to the allocation group. If no allocation group is defined, this parameter is meaningless.

Maximum number of drives within this drive group that this VG is allowed to use simultaneously. The value actually used is the least of the DG's DRIVE_MAXIMUM, this VG's DRIVE_MAXIMUM and the number of drives the DG can physically detect. The maximum is 100; the default is the drive group's DRIVE_MAXIMUM.

Minimum number of seconds that a tape no longer containing valid data must remain unused before the VG overwrites it. The default value is 172,800 seconds (2 days), and the minimum allowed value is 0.

When an LS removes all data from a tape, it sets the hfree (hold free tape) flag bit in the tape's volume (VOL) database entry to prevent that tape from being immediately reused. The next time the LS scans the database for volumes after HFREE_TIME seconds have passed, the LS clears the hfree flag, allowing the tape to be rewritten. If HFREE_TIME is set to 0, the LS will never clear hfree, so an unused tape will not be reused until you clear its hfree flag manually. For a description of how to set and clear the hfree flag manually, see the dmvoladm man page.

Specifies that the VG should break up large files into chunks no larger than this value (specified in bytes) as it writes data to tape. If a file is larger than this size, it is broken up into pieces of the specified size, and, depending on other activity, more than one write child may be used to write the data to tape. If MAX_CHUNK_SIZE is 0 (the default) the VG breaks a file into chunks only when an end of volume is reached.

Specifies the maximum number of write child (dmatwc) processes that will be simultaneously scheduled for the volume group. The maximum value is the value of DRIVE_MAXIMUM for the associated drive group. The minimum value is 1. The default is the value that the volume group uses for DRIVE_MAXIMUM.

Specifies a limit at which the VG will stop scheduling tapes for merging. This number refers to the sum of the active and queued children generated from gets, puts, and merges. The default value for this option is the value used by the volume group for DRIVE_MAXIMUM. This means that if sparse tapes are available, the volume group will create DRIVE_MAXIMUM number of children, thus using tape resources efficiently. However, if any recall requests arrive for that volume group, they will be started before new merges. Setting this number below DRIVE_MAXIMUM, in effect, reserves some tape units for recalls at the expense of merge efficiency. Setting this number above DRIVE_MAXIMUM increases the priority of merges relative to recalls.

Minimum number of unused volumes that can exist in the library server's volume database for this volume group without operator notification. If the number of unused volumes falls below MIN_VOLUMES, the operator is asked to add new volumes. The default is 10; the minimum is zero. If a volume group has an allocation group configured, MIN_VOLUMES is applied to the sum of the number of unused volumes in the volume group and in its allocation group subject to any ALLOCATION_MAXIMUM restrictions.

Specifies the minimum number of seconds a volume group waits after it has requested a drive for a write child before it tells a lower priority child to go away. The default is 3600 seconds.

Specifies the interval, in seconds, after which the volume group will evaluate whether a read child should be asked to go away (even if it is in the middle of recalling a file) so that a higher priority child can be started. If READ_TIME is 0, the volume group will not do this evaluation. The default is 0.

See “Configuring Automated Maintenance Tasks”.

Names the task groups that contain tasks the VG should run. They are configured as objects of TYPE taskgroup. There is no default.

Minutes after which the VG will flush files to tape. The default is 120 minutes.

Specifies approximately how much data the write child should put in a zone. The write child adds files and chunks to a zone until the data written equals or exceeds this value, at which time it writes a tape mark and updates the database. Smaller values allow faster recalls and better recoverability but poorer write performance. The VG also uses zone size to determine when to start write children. The default is 50 MB.

Description

resourcescheduler (type of object)

The resource scheduling algorithm (RSA) to be used. Two are currently supplied: a simple one called fifo, and a more flexible one called weighted_roundrobin (default).

---

Note: Sites can write their own RSA to meet specialized needs. Instructions can be found in the /usr/share/doc/dmf-version_number/info/sample/RSA.readme file.

---

The path name of a Dynamic Shared Object (library of runtime-loadable routines) that contains an RSA whose name was specified by the ALGORITHM parameter. The default is to use the built-in RSAs.

Description

Used to reduce the priority of requests from a volume group that is not the next one preferred by the round robin algorithm. It is a multiplier in the range 0.0 - 1.0. Low values result in the urgency assigned by the VG being totally or partially ignored, and high values mean that the urgency is more important than selecting one whose turn ought to be next. The default is 0.7.

Used to assign a weighting to one or more volume groups. The ratio of these weightings to each other (within the one drive group) determines the number of opportunities the VG has to obtain drives when they are needed.

The weightings are integers in the range 1 - 99, and need not be unique. For efficiency reasons, small numbers are preferred, especially if large numbers of VGs are defined. Usually, there are multiple WEIGHT lines in the configuration, and a given VG might appear on more than one of them. In such cases, the sum of the weights is used as the effective weight for that VG. Any VGs that do not appear on a WEIGHT line are assigned the default of 5. If there are no WEIGHT lines, all VGs will use this default, resulting in a strict round-robin behavior.

WEIGHT has the following format:

Description

resourcewatcher (type of object)

The refresh rate (in seconds) of the generated HTML pages. The default is 60.