About reading backup images with nbtar or tar32.exe
NetBackup uses tar-formatted backup images. By using the NetBackup tar32.exe on Windows or nbtar on UNIX or Linux, NetBackup can understand compressed files, sparse files, long pathnames, and ACL information. It offers features similar to those in cpio.
Although non-NetBackup restore utilities that process tar-formatted images can be used to restore files, they provide only limited restore capabilities. You cannot use the NetBackup tar32.exe or nbtar to extract files from a NetBackup for Windows backup image.
Non-NetBackup restore utilities do not supply all of the restore capabilities that the NetBackup /usr/openv/netbackup/bin/nbtar provides. Possible problems result.
The following is a list of consequences that can occur if using non-NetBackup restore utilities:
Raw partitions cannot be recovered. (This applies to FlashBackup images as well.)
NDMP client backup images cannot be restored, though NDMP vendors may have tools or the utilities that can perform a restore directly from the media.
Non-NetBackup versions of restore utilities may have trouble with sparse files and often skip sparse files.
HP CDFs are restored with non-NetBackup versions of restore utilities. The directory is no longer hidden and the name of the directory has a + appended to it.
If the backup spans more than one piece of media, you must read and combine the fragments from the media to give to the restore utility. To combine the fragments, the system's dd command may be useful.
Another possibility is to use a restore utility on the fragments. To use a restore utility on fragments can allow recovery of any file in the backup other than the one that spanned the media.
Some versions of the HP9000-800 /bin/tar command are known to give a directory checksum error for the second fragment of a backup that crossed media.
Some versions of Solaris tar combine the atime, mtime, and ctime strings with the file name and create the file paths that are not desirable.