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Environment variables supported for dump

Data ONTAP supports environment variables for dump, which have an associated default value. However, you can manually modify these default values.

If you manually modify the values set by the backup application, the application might behave unpredictably. This is because the dump or restore operations might not be doing what the backup application expected them to do. But in some cases, judicious modifications might help in identifying or working around problems.

The following table contains descriptions of what the environment variables supported by Data ONTAP do if they are used:

Note: In most cases, variables that have Y or N values also accept T or F values, respectively.
Environment variable Valid values Default Description
ACL_START return_only none Created by the backup operation, the ACL_START variable is an offset value used by a direct access restore or restartable NDMP backup operation. The offset value is the byte offset in the dump file where the ACL data (Pass V) begins and is returned at the end of a backup. For a direct access restore operation to correctly restore backed up data, the ACL_START value must be passed to the restore operation when it begins. An NDMP restartable backup operation uses the ACL_START value to tell the backup application where the nonrestartable portion of the backup stream begins.
BASE_DATE 0,-1, or DUMP_DATE value -1 Specifies the start date for incremental backups. There is no equivalent option for the dump command. When set to -1, the BASE_DATE incremental specifier is disabled. When set to 0 on a level 0 backup, incremental backups are enabled. Subsequent to the initial backup, the value of the DUMP_DATE variable from the previous incremental backup is assigned to the BASE_DATE variable. These variables are an alternative to the /etc/dumpdates file for controlling incremental backups. These variables are an alternative to the LEVEL/UPDATE based incremental backups.
DEBUG Y or N N Specifies that debugging information is printed.
Note: There is no command line equivalent for the DEBUG variable.
DIRECT Y or N N Specifies that a restore should fast-forward directly to the location on the tape where the file data resides instead of scanning the entire tape. For direct access recovery to work, the backup application must provide positioning information. If this variable is set to Y, the backup application will specify the file or directory names and the positioning information.
DMP_NAME string none Specifies the name for a multiple subtree backup. The DMP_NAME variable is equivalent to the n option of the dump command. This variable is mandatory for multiple subtree backups.
DUMP_DATE return_value none You do not change this variable directly. It is created by the backup if the BASE_DATE variable is set to a value other than -1. The DUMP_DATE variable is derived by prefixing the 32-bit level value to a 32-bit time value computed by the dump software. The level is incremented from the last level value passed into the BASE_DATE variable. The resulting value is used as the BASE_DATE value on a subsequent incremental backup.
ENHANCED_DAR_ENABLED Y or N N Specifies if enhanced DAR functionality is instantiated. Enhanced DAR functionality supports directory DAR, and DAR of files with NT Streams. It provides performance improvements. Enhanced DAR during restore is possible only if the following conditions are met:
  • Data ONTAP supports enhanced DAR in Data ONTAP 6.4 or later
  • File history is enabled (HIST=Y) during the backup
  • The ndmpd.offset_map.enable option is set to "on"
  • ENHANCED_DAR_ENABLED variable is set to "Y" during restore
EXCLUDE pattern_string none Specifies files or directories that are excluded when backing up data. The EXCLUDE variable is equivalent to the X option of the dump command. The exclude list is a comma-separated list of file or directory names. If the name of a file or directory matches one of the names in the list, it is excluded from the backup. The following are rules for specifying names in the exclude list:
  • The exact name of the file or directory must be used.
  • An asterisk (*) is a wildcard character. The asterisk must be either the first or the last character of the string. Each string can have up to two asterisks.
  • A comma in a file or directory name must be preceded with a backslash.
  • The exclude list can contain up to 32 names.
EXTRACT Y, N, or E N Specifies that subtrees of a backed-up data set are to be restored. The EXTRACT variable is equivalent to the x option of the restore command. The backup application specifies the names of the subtrees to be extracted. If a file name specified matches a directory whose contents were backed up, the directory is recursively extracted. To rename a file, directory, or qtree during restore without using DAR, you must set the EXTRACT environment variable to E.
EXTRACT_ACL Y or N Y Specifies that ACLs from the backed up file are restored on a restore operation. The EXTRACT_ACL variable is equivalent to the A option of the restore command. The default is to restore ACLs when restoring data, except for DARs (DIRECT=Y).
FILESYSTEM string none Specifies the path name of the root of the data that is being backed up. For example, /vol/vol0/etc.
FORCE Y or N N The FORCE variable is equivalent to the F option of the restore command.

Determines if the restore operation must check for volume space and inode availability on the destination volume.

Setting this variable to Y causes the restore operation to skip checks for volume space and inode availability on the destination path.

If there is not enough volume space or inodes available on the destination volume, the restore operation recovers as much data allowed by the destination volume space and inode availability. The restore operation stops when there is no more volume space or inodes left.

HIST Y or N N Specifies that file history information is sent to the backup application. Most commercial backup applications set the HIST variable to Y. If you want to increase the speed of a backup operation, or you want to troubleshoot a problem with the file history collection, you can set this variable to N.
Note: You should not set the HIST variable to Y if the backup application does not support file history.
IGNORE_CTIME Y or N N Specifies that a file is not incrementally backed up if only its ctime value has changed since the previous incremental backup. Some applications, such as virus scanning software, change the ctime value of a file within the inode, even though the file or its attributes have not changed. As a result, an incremental backup might back up files which have not changed. The IGNORE_CTIME variable should be specified only if incremental backups are taking an unacceptable amount of time or space because the ctime value was modified.
IGNORE_QTREES Y or N N Specifies that the restore operation does not restore qtree information from backed up qtrees. The IGNORE_QTREES variable is equivalent to the Q option of the restore command.
LEVEL 0-9 0 Specifies the backup level. Level 0 copies the entire data set. Incremental backup levels, specified by values above 0, copy all files new or modified since the last incremental backup. For example, a level 1 backs up new or modified files since the level 0 backup, a level 2 backs up new or modified files since the level 1 backup, and so on.
LIST Y or N N Lists the backed-up file names and inode numbers without actually restoring the data. The LIST variable is equivalent to the t option of the restore command.
LIST_QTREES Y or N N Lists the backed-up qtrees without actually restoring the data. The LIST_QTREES variable is equivalent to the T option of the restore command.
MULTI_SUBTREE_ NAMES string none Specifies that the backup is a multiple subtree backup. The MULTI_SUBTREE_NAMES variable is equivalent to the l option of the dump command. Multiple subtrees are specified in the string which is a newline-separated, null-terminated list of subtree names. Subtrees are specified by path names relative to their common root directory, which must be specified as the last element of the list. If you use this variable, you must also use the DMP_NAME variable.
NDMP_UNICODE_ FH Y or N N Specifies that a Unicode name is included in addition to the NFS name of the file in the file history information. This option is not used by most backup applications and should not be set unless the backup application is designed to receive these additional file names. The HIST variable must also be set.
NDMP_VERSION return_only none You should not modify the NDMP_VERSION variable. Created by the backup operation, the NDMP_VERSION variable returns the NDMP version. Data ONTAP sets the NDMP_VERSION variable during a backup for internal use and to pass to a backup application for informational purposes. The NDMP version of an NDMP session is not set with this variable.
NO_ACLS Y or N N Specifies that ACLs not be copied when backing up data. The NO_ACLS variable is equivalent to the A option of the dump command. Ordinarily a backup using the dump command writes out metadata related to Windows ACLs. The NO_ACLS variable stops this information from being backed up.
NON_QUOTA_TREE Y or N N Specifies that files and directories in qtrees be ignored when backing up data. The NON_QUOTA_TREE variable is equivalent to the Q option of the dump command. When set to Y, items in qtrees in the data set specified by the FILESYSTEM variable are not backed up. This variable has an effect only if the FILESYSTEM variable specifies an entire volume. The NON_QUOTA_TREE variable only works on a level-0 backup and does not work if the MULTI_SUBTREE_NAMES variable is specified.
NOWRITE Y or N N Specifies that the restore operation not write data to the disk. The NOWRITE variable is equivalent to the N option of the restore command. This variable is used for debugging.
PATHNAME_SEPARATOR return_value none Specifies the pathname separator character. This character depends upon the file system being backed up. For Data ONTAP, the character "/" is assigned to this variable. NDMP server sets this variable prior to starting a tape backup operation.
RECURSIVE Y or N Y Specifies that directory entries during a DAR restore be expanded. The DIRECT and ENHANCED_DAR_ENABLED environment variables must be enabled (set to Y) as well. If the RECURSIVE variable is disabled (set to N), only the permissions and ACLs for all the directories in the original source path are restored from tape, not the contents of the directories. If the RECURSIVE variable is N or the RECOVER_FULL_PATHS variable is Y, the recovery path must end with the original path.
Note: If the RECURSIVE variable is disabled and if there are more than one recovery path, all the recovery paths must be contained within the longest of the recovery paths. Otherwise, an error message is displayed.
For example, the following are valid recovery paths as all the recovery paths are within foo/dir1/deepdir/myfile:
  • /foo
  • /foo/dir
  • /foo/dir1/deepdir
  • /foo/dir1/deepdir/myfile
The following are invalid recovery paths:
  • /foo
  • /foo/dir
  • /foo/dir1/myfile
  • /foo/dir2
  • /foo/dir2/myfile
RECOVER_FULL_PATHS Y or N N Specifies that full recovery path will have their permissions and ACLs restored after the DAR. DIRECT and ENHANCED_DAR_ENABLED must be enabled (set to Y) as well. If RECOVER_FULL_PATHS is Y, recovery path must end with the original path. If directories already exist on the destination volume, their permissions and ACLs will not be restored from tape.
TYPE dump or smtape dump Specifies the type of backup you can choose to perform tape backup and restore operations. Data ONTAP supports two types of backup: the dump backup and SMTape backup.
UPDATE Y or N Y Updates the metadata information to enable LEVEL based incremental backup.
VERBOSE Y or N N Increases the log messages while performing a tape backup or restore operation.