Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!panda!husc6!harvard!seismo!munnari!basser!uqcspe!tony From: tony@uqcspe.OZ (Tony O'Hagan) Newsgroups: net.unix-wizards Subject: Re: need help with multi-reel cpio Message-ID: <862@uqcspe.OZ> Date: Thu, 15-May-86 02:23:21 EDT Article-I.D.: uqcspe.862 Posted: Thu May 15 02:23:21 1986 Date-Received: Sat, 17-May-86 03:34:54 EDT References: <520@sdcc13.UUCP> <461@ncr-sd.UUCP> <529@isis.UUCP> Organization: Computer Science, Queensland Uni, Australia Lines: 156 Keywords: cpio tape backup Summary: How we fixed it What we did was write a filter to handle output from any program (e.g. cpio/tar/cat etc.) to write on several volumes. (e.g. floppies/tapes) It has been tested under V7 & Sys 3 and for several tapes and floppies. The doc follows :- MULTIVOL(8) UNIX Programmer's Manual MULTIVOL(8) NAME multivol - handle multivolume files SYNOPSIS multivol -o [-vtw] [-b blocksize] [-n count] [-l label] [device] multivol -i [-vtw] [device] multivol -t [device] DESCRIPTION Multivol allows for the convenient use of multivolume files such as when backing up to several floppy disks. With the -o option, multivol reads the standard input file, breaks it into volumes and writes them to the device. With -i, it reads volumes from the device, concatenates them and writes the resultant file to standard output. You may not specify both -i and -o. The device to use is given by the device argument, or /dev/multivol if none is specified. Normally this will be a character special file corresponding to a raw disk or tape unit. It does not have to be a random access device: mul- tivol only accesses it sequentially. However, multivol may re-open a volume in order to rewind devices such as magnetic tape. The -b blocksize argument specifies the physical block size to be used. This number may end with k or b to specify mul- tiplication by 1024 or 512 respectively. With a floppy disk it can usefully be made the size of one track. The default physical block size is 512 bytes. If the device or its driver does not allow successful writing all the way to the end of a physical volume, such as with magnetic tape, the -n count options should be used to specify the maximum number of physical blocks to be written on one volume. The -l label option allows the user to supply a short string to be written onto the volume for identification purposes. Before reading or writing a new volume, multivol prompts on the controlling terminal for the user to insert the appropriate volume into the physical device and waits for a new-line to be typed. With -i, if the volume inserted is not an multivol volume, is not the next volume in sequence or does not have the same date stamp as the previous volume multivol asks you whether you really want to try and read it. Printed 15/5/86 local 1 MULTIVOL(8) UNIX Programmer's Manual MULTIVOL(8) Multivol puts some extra information on each volume. It is in ASCII so that it is machine independent. Hence the actual amount of data stored on each volume will be slightly less than its physical size. The -t option prints some of this information on standard error. It includes: o the date that the volume was written o the sequence number of the volume o any label string supplied at the time the volume was written If you specify -w with -i or -o multivol assumes the -t option also and asks you to verify that each volume really is the required one. The -v option tells multivol to write various other verbose information on standard error such as an indication of how many blocks it has read or written. EXAMPLES Tell me what you know about this volume: multivol -t Backup a directory to the default device: tar cf - mydir | multivol -o and retrieve it again: cd mydir multivol -i | tar xf - Backup to tape all files changed since last time: touch /etc/multivoldate1 find / -newer /etc/multivoldate2 -print | cpio -ov | multivol -o -l WEEKLY -b 20k -n 1000 /dev/rmt0 mv /etc/multivoldate1 /etc/multivoldate2 Retrieve a file from that backup: cd / multivol -i /dev/rmt0 | cpio -idmv usr/myname/myfile FILES /dev/tty where prompt is written and response is read /dev/multivolthe default device SEE ALSO tar(1), cpio(1), dd(1), dump(8), ``your device''(4) DIAGNOSTICS A message is written on standard error and multivol ter- minates in the event of Printed 15/5/86 local 2 MULTIVOL(8) UNIX Programmer's Manual MULTIVOL(8) o incorrect usage o not being able to open the device o not being able to open the controlling terminal o an I/O error on the device BUGS In the event of an I/O error you may have to start again with the first volume depending on the nature of the file and the program which produced it. In many cases it simply means the end of the volume has been reached, and no more can be read/written. If a block limit has been set multivol will indicate this condition. When reading, multivol attempts to determine the block size from the volume header, however some raw devices will return an I/O error if the block size used for reading does not match that used for writing, hence the volume header cannot be read unless the original block size is also specified. Volume labels may not contain white space and are limited to 14 characters. Many tape device drivers cannot handle a read/write request while the tape is rewinding, for such drivers the -w switch is recommended in place of just -t Printed 15/5/86 local 3 Tony O'Hagan Australia: (07) 3774125 International: +61 7 3774125 University of Queensland CSNET: tony@uqcspe.oz ACSnet: tony@uqcspe.oz Dept. of Computer Science UUCP: ...!seismo!munnari!uqcspe.oz!tony St. Lucia, Brisbane, ARPA: tony%uqcspe.oz@seismo.css.gov AUSTRALIA 4067 JANET: uqcspe.oz!tony@ukc