Date: 10 Jun 1999 04:10:18 -0000 From: thompson@tgsoft.com To: FreeBSD-gnats-submit@freebsd.org Subject: bin/12107: new feature for dump, when -a does not work Message-ID: <19990610041018.19600.qmail@moose.tgsoft.com>
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>Number: 12107
>Category: bin
>Synopsis: Add switch to dump to support multiple dumps on one tape
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Wed Jun 9 21:20:00 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator: mark thompson
>Release: FreeBSD 3.2-STABLE i386
>Organization:
tgsoft
>Environment:
I have an older HP-by-Phillips DAT drive that is used for
backups. Unfortunately, dump -a does not do the right thing on this
drive, which makes it challenging to pack several filesystems on a
single tape (which you want to do, since several of the filesystems
are way smaller than a tape-full.
>Description:
When putting the n'th dump on a tape, you would like to tell dump how
much tape is left, so that it will ask for a new one at an appropriate
time. This patch adds the ability to say "the tape is -B blocks long,
but -F blocks are already used; so ask for a new tape when this is
full. The new tape will be -B blocks long".
>How-To-Repeat:
On my machine, with this drive and 3.2, write a tape using dump -a
that extends over a tape boundary. Try to restore the resulting 2
tapes.
>Fix:
Simple patch enclosed. Also an example perl program to use it.
----------- PATCH -------------
--- dump.8.ORIG Wed Jun 9 08:20:52 1999
+++ dump.8 Wed Jun 9 08:22:49 1999
@@ -104,6 +104,10 @@
The number of 1 KB blocks per volume.
This option overrides the calculation of tape size
based on length and density.
+.It Fl F Ar records
+The number of 1 kB blocks that have already been written on the first volume.
+Those blocks will be considered used when calculating the amount of tape
+left on this volume only.
.It Fl a
.Dq auto-size .
Bypass all tape length considerations, and enforce writing
--- main.c.ORIG Wed Jun 9 08:15:24 1999
+++ main.c Wed Jun 9 13:47:55 1999
@@ -85,6 +85,7 @@
int dokerberos = 0; /* Use Kerberos authentication */
long dev_bsize = 1; /* recalculated below */
long blocksperfile; /* output blocks per file */
+long blocksthisvol; /* our position on the tape */
char *host = NULL; /* remote host (if any) */
static long numarg __P((char *, long, long));
@@ -122,9 +123,9 @@
obsolete(&argc, &argv);
#ifdef KERBEROS
-#define optstring "0123456789aB:b:cd:f:h:kns:T:uWw"
+#define optstring "0123456789aB:b:cd:F:f:h:kns:T:uWw"
#else
-#define optstring "0123456789aB:b:cd:f:h:ns:T:uWw"
+#define optstring "0123456789aB:b:cd:F:f:h:ns:T:uWw"
#endif
while ((ch = getopt(argc, argv, optstring)) != -1)
#undef optstring
@@ -159,6 +160,10 @@
ntrec = HIGHDENSITYTREC;
break;
+ case 'F': /* first block number */
+ blocksthisvol = numarg("starting block number",
+ 0L, 0L);
+ break;
case 'f': /* output file */
tape = optarg;
break;
@@ -596,6 +601,7 @@
case 'b':
case 'd':
case 'f':
+ case 'F':
case 'h':
case 's':
case 'T':
--- tape.c.ORIG Wed Jun 9 08:16:37 1999
+++ tape.c Wed Jun 9 08:19:58 1999
@@ -74,7 +74,7 @@
long lastspclrec = -1; /* tape block number of last written header */
int trecno = 0; /* next record to write in current block */
extern long blocksperfile; /* number of blocks per output file */
-long blocksthisvol; /* number of blocks on current output file */
+extern long blocksthisvol; /* number of blocks on current output file */
extern int ntrec; /* blocking factor on tape */
extern int cartridge;
extern char *host;
@@ -619,9 +619,12 @@
enslave(); /* Share open tape file descriptor with slaves */
asize = 0;
- blocksthisvol = 0;
- if (top)
+ if (top) {
newtape++; /* new tape signal */
+ }
+ else {
+ blocksthisvol = 0; /* Not the first tape */
+ }
spcl.c_count = slp->count;
/*
* measure firstrec in TP_BSIZE units since restore doesn't
-------- Example of usage --------------
#!/usr/bin/perl
$TAPENAME="/dev/nrsa0";
$TAPELENG=1200000; # in 1K blocks
$today=`date +%Y%m%d`;
chomp $today;
$LOGFILE="/var/log/dump.$today";
open LOG, ">>$LOGFILE";
print LOG `date`;
REW1:
while (1) {
print "Please mount first tape\n";
$red = read STDIN, $buf, 1;
$rc = system "mt -f $TAPENAME rewind";
# print "rewind: rc $rc\n";
last REW1 if (($rc & 0xffff) == 0);
}
$skip=1;
$pos=0;
$| = 1; # Immediate flush
# each file system
while ($ARGV[0]) {
close LOG;
open LOG, ">>$LOGFILE";
# prvent silly tapes
$left = $TAPELENG - $pos;
if ($left < 1000) {
print LOG "--- new tape because $left blocks left ---\n";
print "*** Not much tape left\n";
system "mt -f $TAPENAME offline";
REW2:
while (1) {
print "Please mount next tape\n";
$red = read STDIN, $buf, 1;
$rc = system "mt -f $TAPENAME rewind";
# print "rewind: rc $rc\n";
last REW2 if (($rc & 0xffff) == 0);
}
$skip = 1;
$pos = 0;
}
# now dump it
print LOG "=== $ARGV[0]: restore ifbs $TAPENAME 1 $skip ===\n";
print LOG "=== dump -0 -f $TAPENAME -B $TAPELENG -F $pos $ARGV[0] ===\n";
$pid = open DUMP,
"dump -0 -f $TAPENAME -B $TAPELENG -F $pos $ARGV[0] 2>&1 > /dev/tty </dev/tty |";
die "can't start dump" if ($pid == 0);
print "Dump: pid $pid\n";
while (<DUMP>) {
print ;
print LOG $_;
if (m+DUMP: DUMP: ([0-9]*) tape blocks on ([0-9]*) volumes+) {
$BLOCKS=$1;
$VOLUMS=$2;
}
}
# dump exits
close DUMP;
$rc = $? & 0xffff;
die "Dump failed" if ($rc);
print "Dump: $BLOCKS blocks $VOLUMS volumes\n";
# how much did we use
$old="";
if ($VOLUMS > 1) { # tape changed in middle
$pos = $BLOCKS;
$old = " new";
$skip = 2;
}
else {
$pos = $BLOCKS;
$skip++;
}
$left = $TAPELENG - $pos;
$pct = $left / ($TAPELENG/100);
print LOG "--- Estimate $left blocks ($pct) on$old tape ---\n";
shift; # next
}
system "mt -f $TAPENAME offline";
print LOG `date`;
close LOG;
exit 0;
---------- Thank you for your consideration ---------
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