To backup the GFS Shared File System in file system unit, use dd(1). The following describes the backing-up procedure using dd(1).
See
For details about dd(1), see the online manual.
Entire-file-system backing-up allows backing-up of the entire file system more quickly than file-by-file backing-up. However, a file system backed up with this method cannot be restored on a file-by-file basis during restoring.
Before executing backing-up, use the following procedure to check the partition information for the desired GFS Shared File System. Estimate the backing-up media capacity required for backing-up and the number of required media and then unmount of the GFS Shared File System.
The following describes examples of tape backup in case of single partition configuration and multi-partition configuration.
Use sfcinfo(8) to display partition information and check that the file system has only a single partition (same special file names) and that the capacity of the device, backup destination, is sufficient. The size of the partition can be estimated by adding 1 megabyte to the sum of the values displayed in the size field (in kilobytes).
Example: Backup in case of single partition
# sfcinfo /dev/sfdsk/gfs01/dsk/volume01 <Enter> FSID special size Type mount 1 /dev/sfdsk/gfs01/dsk/volume01(1e756) 14422 META ----- 1 /dev/sfdsk/gfs01/dsk/volume01(1e756) 5116 LOG ----- 1 /dev/sfdsk/gfs01/dsk/volume01(1e756) 95112 DATA ----- # dd if=/dev/sfdsk/gfs01/dsk/volume01 of=/dev/st0 bs=1024k <Enter> |
dd(1) can handle one partition at a time. For a multi-partition configuration, therefore, the partitions must be backed up one at a time. Use sfcinfo(8) to check the partition configuration then backup each partition with the same procedure as used for a single partition configuration.
Example: Backup in case of two partitions
# sfcinfo /dev/sfdsk/gfs01/dsk/volume01 <Enter> FSID special size Type mount 1 /dev/sfdsk/gfs01/dsk/volume01(1e756) 14422 META ----- 1 /dev/sfdsk/gfs01/dsk/volume01(1e756) 5116 LOG ----- 1 /dev/sfdsk/gfs01/dsk/volume01(1e756) 95112 DATA ----- 1 /dev/sfdsk/gfs01/dsk/volume02(1e757) 95112 DATA ----- # dd if=/dev/sfdsk/gfs01/dsk/volume01 of=/dev/st0 bs=1024k <Enter> (Change tape) # dd if=/dev/sfdsk/gfs01/dsk/volume02 of=/dev/st0 bs=1024k <Enter> |
Note
All the partitions making up the desired GFS Shared File System must be backed up. Avoid backing-up and storing only some of the partitions.
The tapes used for backups must be labeled so that the backed up partitions can be identified. They must then be stored as a set.
dd(1) does not support multi-tape volumes. If the file system is too large to fit on a single tape, data needs to be divided and backed up. In such cases, set bs (block length) and count (number of blocks) and increase skip (input-side offset (number of blocks)) by the value of count.
Example: Backup in case of separating partition as blocks in units of 1 gigabyte
# dd if=/dev/sfdsk/gfs01/dsk/volume01 of=/dev/st0 bs=1024k count=1024 <Enter> (Change tape) # dd if=/dev/sfdsk/gfs01/dsk/volume01 of=/dev/st0 bs=1024k count=1024 skip=1024 <Enter> (Change tape) # dd if=/dev/sfdsk/gfs01/dsk/volume01 of=/dev/st0 bs=1024k count=1024 skip=2048 <Enter> (Change tape) # dd if=/dev/sfdsk/gfs01/dsk/volume01 of=/dev/st0 bs=1024k count=1024 skip=3072 <Enter> ... |
