01/10/95, 4FAX# 1959 Restoring Multiple Tape Blocks with "restore" Command SPECIAL NOTICES Information in this document is correct to the best of our knowledge at the time of this writing. Please send feedback by fax to "AIXServ Information" at (512) 823-4009. Please use this information with care. IBM will not be responsible for damages of any kind resulting from its use. The use of this information is the sole responsibility of the customer and depends on the customer's ability to eval- uate and integrate this information into the customer's operational environment. ABOUT THIS DOCUMENT This document addresses the problem of multiple backup images on an 8mm tape in which "restore -Tf/dev/rmt0.1" dis- plays the NEXT image instead of the current image. PROBLEM DESCRIPTION When there are multiple backup images on an 8mm tape, "restore -Tf/dev/rmt0.1" displays the next image instead of the current image. This occurs because of the way the "restore" command works. First, it reads 512 bytes from the tape (the backup image header) to determine the block size of the image. Then it reverses the tape 512 bytes and reads the header and the ensuing data of the backup image. But, if "rmt0.1" (or "rmt0.5") is specified, the device driver does not allow the "restore" command to reverse the tape, so it goes on and finds the next header and reads that backup image. (Note: If you were using a block size other than 512 bytes, you would have gotten a "restore: not in backup format" error instead.) In InfoExplorer, see topic "restore Command", where it says in Note 4, "Do not use the no-rewind tape device for restoring unless the '-s' flag is specified." HOW TO RESTORE The following example assumes the stacked tape was created with files in directories /data, /history, /usr, and /u and with the following commands: | cd /data | find . -print | backup -ivqf/dev/rmt#.1 | cd /history | find . -print | backup -ivqf/dev/rmt#.1 | cd /usr | find . -print | backup -ivqf/dev/rmt#.1 | cd /u | find . -print | backup -ivqf/dev/rmt#.1 Restoring Multiple Tape Blocks with "restore" Command 1 01/10/95, 4FAX# 1959 To restore from a stacked tape, use the "-s" option of the "restore" command. For example, to restore the files from the first three backup images on the tape, enter: tctl -f/dev/rmt0 rewind (Just to make sure it's rewound) | restore -s1 -xvf/dev/rmt#.1 (Restore files from 1st image) | restore -s1 -xvf/dev/rmt#.1 (Restore files from 2nd image) | restore -s1 -xvf/dev/rmt#.1 (Restore files from 3rd image) To go directly to the third image and restore its files, use: tctl -f/dev/rmt0 rewind (Just to make sure it's rewound) | restore -s3 -xvf/dev/rmt#.1 (Restore 3rd image) Restoring Multiple Tape Blocks with "restore" Command 2 01/10/95, 4FAX# 1959 READER'S COMMENTS Please fax this form to (512) 823-4009, attention "AIXServ Informa- tion". You may also e-mail comments to: elizabet@austin.ibm.com. These comments should include the same customer information requested below. Use this form to tell us what you think about this document. If you have found errors in it, or if you want to express your opinion about it (such as organization, subject matter, appearance) or make sug- gestions for improvement, this is the form to use. If you need technical assistance, contact your local branch office, point of sale, or 1-800-CALL-AIX (for information about support offer- ings). These services may be billable. Faxes on a variety of sub- jects may be ordered free of charge from 1-800-IBM-4FAX. Outside the U.S. call 415-855-4329 using a fax machine phone. When you send comments to IBM, you grant IBM a nonexclusive right to use or distribute your comments in any way it believes appropriate without incurring any obligation to you. NOTE: If you have a problem report or item number, supplying that number may help us determine why a procedure did or did not work in your specific situation. Problem Report or Item #: Branch Office or Customer #: Be sure to print your name and fax number below if you would like a reply: Name: Fax Number: ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ ______________________________________________________________________ END OF DOCUMENT (restore-s.bak, 4FAX# 1959) Restoring Multiple Tape Blocks with "restore" Command 3