Re: tar program not suitable for backup?

Ngo Lip Wee <lwngo_at_tmi.com.sg> wrote:
>I am using Digital Unix 3.0 and Oracle 7.1.3. I was told that
>the tar program is not suitable for database backup, owing to
>the following scenario:
 

>It seems that the tar program packs the datafiles (database
>files are sparse in our case) as reflected by df. The concern
>here is will the 'free space' as reported by df (they shouldn't
>be free, they should be reserved for future table expansions)
>be used for some other unrelated files, causing problems to my
>database later.

Oracle creates files that are full of actual zeros and fills them up over time. The default versions of tar and cpio in Digital UNIX V3.X see these long strings of zeros and misinterpret them as sparse files. To get a version of the tar and cpio that work correctly for Oracle backups install the Obsolete Commands subset and replace tar and cpio with the files in /usr/opt/sterling.

This is documented in the Oracle install and user guid fro Digital UNIX. Received on Thu Feb 01 1996 - 00:00:00 CET