Re: ORACLE v7 Export to Tape problems

In a previous article, skscci_at_zeus.IntNet.net (Steven Shapiro) says:

>Howdy All!
>
>Due to the large size of our database, exporting it to disk and then
>copying to tape is unreasonable. As such, we would like to directly
>export it to tape. However, we can't seem to figure out the magical
>incantation. We've spoken to Oracle about this and they admit it is a bug.

   I ran into the same problem. The problem is with import not respecting the RECORDLENGTH parameter so that it does not read the tape with the correct blocking factor. I have successfully exported to and imported from tape with the following technique:

   Make sure you specify the RECORDLENGTH parameter to export. It will then write records to tape with that block size. (Hint: the greater the block size, the fewer inter-record gaps on the tape and the more you will be able to fit). You will likely want to check with the tape drive specs to see what block sizes it is comfortable with.

eg:

exp userid=system/manager file=/dev/rst0 full=y recordlength=8192 volsize=1000M

   The trick to running import is to use dd to read the tape (with the correct block size) and then pass the contents to imp via a named pipe:

mknod /tmp/orapipe p /* Or is it mknod p /tmp/orapipe...check the man page */

dd if=/dev/rst0 of=/tmp/orapipe bs=8192 &

imp file=/tmp/orapipe recordlength=8192 commit=y ....

rm /tmp/orapipe

   This works for me.

• Doug Harris Database Administrator, System Development Division, Statistics Canada ## Standard Disclaimer Applies ## --