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vdump(8) System Manager's Manual vdump(8) NAME vdump - performs full and incremental backups on mounted filesets SYNOPSIS /sbin/vdump -h /sbin/vdump -V /sbin/vdump -w /sbin/vdump [-0..9] [-CD- NUquv] [-F num_buffers] [-T tape_num] [-b size] [-f device] [-x num_blocks] fileset PARAMETERS Specifies the full path name of a mounted AdvFS fileset to be backed up. Alternatively, specifies a mounted NFS or UFS file system. When used with the -D flag, specifies a subdirectory. FLAGS Displays usage help for vdump. Displays the current version of vdump. Displays the filesets that have not been backed up within one week. Specifies the backup level. The value 0 for this flag causes the entire fileset to be backed up to the storage device. The default backup level is 9. Compresses the data as it is backed up, which minimizes the saveset size. Performs a level 0 backup on the specified subdirec- tory. This flag overrides any backup level specification in the com- mand. If this flag is specified, the AdvFS user and group quota files and the fileset quotas are not backed up. Does not rewind the storage device, when it is a tape. Does not unload the storage device, when it is a tape. Displays only error messages; does not display information messages. Updates the /etc/vdumpdates file with a timestamp entry from the beginning of the backup. Displays the names of the files being backed up. Specifies the number of in-memory buffers to use. The valid range is 2 through 64 buffers; the default is 8 buffers. The size of the in-memory buffers is determined by the value of the -b flag. Specifies the starting number for the first tape. The default number is 1. The tape number is used only to prompt the operator to load another tape in the drive. Specifies the number of 1024-byte blocks per record in the saveset. The valid range is 1 through 64 blocks; the default is 60 blocks per record. The value of this flag also determines the size of the in-memory buffers. Specifies the des- tination of the saveset, which can be a device, a file, or, when the - (dash) character is specified, standard output. Specifies an "exclu- sive or" (XOR) operation each time the blocks specified by num_blocks are written to the saveset. The XOR operation is performed on the blocks and the results written to the saveset as an XOR block that im- mediately follows the blocks. Subsequently, you can use the vrestore command to recover one of the blocks in the group should a read error occur. The valid range is 1 through 32 blocks; the default is 8 blocks. Using the -x flag creates larger savesets and increases the amount of time required to back up a file system, but offers additional protection from saveset errors. DESCRIPTION The vdump command backs up files from a single mounted fileset or clone fileset to a local storage device. The vdump command is the backup fa- cility for the AdvFS file system. However, the vdump command is file- system independent, and you can use it to back up other file systems, such as UFS and NFS. The vdump command backs up all files in the specified fileset that are new or changed since a certain date and produces a saveset on the stor- age device. The date is determined by comparing the specified backup level to previous backup levels recorded in the /etc/vdumpdates file. The default storage device is /dev/rmt0h. You can specify an alternate storage device by using the -f flag. The vdump command performs either an incremental backup, level 9 to 1, or a full backup, level 0, depending on the desired level of backup and the level of previous backups recorded in the /etc/vdumpdates file. The vdump command backs up all files that are new or have changed since the latest backup date of all backup levels that are lower than the backup level being performed. If a backup level that is lower than the specified level does not exist, the vdump command initiates a level 0 backup. A level 0 backup backs up all the files in the fileset. After the backup operation is complete, you can use the vrestore -t command to verify that the backup contains the files you wanted to save. The vrestore -t command lists the name and size of each file in the saveset without restoring them. When you specify the -C flag, the vdump command backs up the files with compression. You cannot specify the compression ratio, it is deter- mined by the contents of the dump. When you specify the -u flag, the vdump command enters a time-stamp en- try of that fileset and its backup level into the /etc/vdumpdates file. If a file-system entry with a specific backup level does not already exist in the /etc/vdumpdates file, the vdump command appends the file with a new vdump record; otherwise, the vdump command overwrites the existing record, changing the backup date to reflect the most current backup session. This occurs after all files in the named fileset have been successfully backed up. The vdump and vrestore commands save and restore AdvFS sparse files. However, sparse files that have been striped are still handled in the fashion of releases earlier than DIGITAL UNIX Version 4.0D: they are allocated disk space and filled with zeros. You do not have to be the root user to use the vdump command. The Ad- vFS quota files and fileset quotas in the fileset are included in a saveset when you are the root user and a full fileset is saved. AdvFS quota files and fileset quotas can only be backed up for locally- mounted filesets. Under normal usage, the vdump command uses a small amount of additional space on the storage device, typically less than 1 percent, when a fileset is backed up. If the -x flag is used, the amount of additional space used to back up the fileset increases. RESTRICTIONS The vdump command does not back up filesets that are not mounted. Filesets backed up by using the vdump command must be restored by using the vrestore command. The vdump command is not interchangeable with the dump command. Similarly, the vrestore command is not interchange- able with the restore command. The vrestore command in DIGITAL UNIX versions earlier than Version 4.0 cannot be used to restore savesets produced by the vdump command in DIGITAL UNIX Version 4.0 or higher systems. The /etc/vdumpdates file is written in ASCII and consists of a single record per line. You must be the root user to update this file or to change any record field. If you edit the /etc/vdumpdates file, be cer- tain that all records follow the correct format. An incorrectly for- matted record in this file may make the file inaccessible for updates or reads. EXAMPLES A typical /etc/vdumpdates file includes entries like the following, defining the fileset name, last backup level, and date: dmn2#set2 8 wed Mar 3 07:40:35 1993 dmn2#set2 9 Thu Mar 4 07:20:42 1993 dmn2#set2 3 Fri Mar 5 07:47:37 1993 dmn2#set2 7 Thu Mar 4 08:23:05 1993 /dev/rz0g 0 Mon Mar 8 12:11:42 1993 In this example, dmn2#set2 represents an AdvFS fileset; /dev/rz0g represents a UFS file system. If you perform a level 8 backup of the dmn2#set2, using this /etc/vdumpdates file, you can expect the following results: The vdump command ignores the /dev/rz0g entry, because it does not match the specified file- set, dmn2#set2. The vdump command ignores the level 8 and 9 en- tries, because these entries are equal to or higher than the level 8 backup you requested. This leaves only the level 3 and 7 entries. Of the two remaining entries, the vdump command chooses the entry with the most recent dump date, which is the level 3 entry. The vdump command backs up all files that were created or modified after the dump date of the level 3 entry. the vdump command modifies the access time of each file in the fileset. To perform a full level 0 backup, enter a command sim- ilar to the following: % vdump -0 -u -f /dev/rmt1h /fs1 In this example, -0 specifies that all files in the fileset /fs1 will be backed up to /dev/rmt1h; -u specifies vdump to update the /etc/vdumpdates after a successful backup of the fileset. When the backup saveset device is the character - (dash), the vdump command writes to standard output. Thus, the vdump and vrestore commands may be used in a pipeline expression to copy filesets. The following are typical commands, both are equiva- lent: # vdump -0 -f - /usr | (cd /mnt; vrestore -x -f -) # vdump -0f - /usr | vrestore -xf - -D /mnt For weekly tape backups, a set of 5 tapes per backed up fileset can be used on a cyclical basis. Each month a level 0 backup is taken on a set of fresh tapes that are saved until the next level 0 backup. The follow- ing is a guideline for the level of backup to perform during weekly, biweekly, and monthly periods. tab(@); cfHB cfHB cfHB cfHB cfHB cfHB l l l l l l. _ @M@Tu@W@Th@F _ Weekly@0@3@2@5@4 Biweekly@0@3@2@5@4 @0@9@8@9@9 Monthly@0@3@2@5@4 @1@9@8@9@9 @1@3@2@5@4 @1@9@8@9@9 @@@@@ _ FILES Specifies the vdump command path. Contains a list of filesets that were backed up, the date that each file system was backed up, and the backup level. Contains the full path names and mount points of file- sets. RELATED INFORMATION vrestore(8), mount(8), umount(8). delim off vdump(8)