The following options are not normally used on a day to day basis.
However, some of them can be quite important when the need arises. One
such option is --rebuilddb.
We all hope the day never comes, and for many of us, it never does.
But still, there is a chance that one day, while you're busy using RPM
to install or upgrade a package, you'll see this message:
free list corrupt (42)- contact rpm-list@redhat.com
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Once this happens, you'll find there's very little that you can do,
RPM-wise. However, before you fire off an e-mail to the RPM mailing
list, you might try the
--rebuilddb option. The
format of the command is simple:
The command produces no output, either. After a few minutes, it
completes with nary a peep. Here's an example of
--rebuilddb being used on an RPM database that
wasn't corrupt. First, let's look at the files that comprise the
database:
# cd /var/lib/rpm
# ls
total 3534
-rw-r--r-- 1 root root 1351680 Oct 17 10:35 fileindex.rpm
-rw-r--r-- 1 root root 16384 Oct 17 10:35 groupindex.rpm
-rw-r--r-- 1 root root 16384 Oct 17 10:35 nameindex.rpm
-rw-r--r-- 1 root root 2342536 Oct 17 10:35 packages.rpm
-rw-r--r-- 1 root root 16384 Oct 17 10:35 providesindex.rpm
-rw-r--r-- 1 root root 16384 Oct 17 10:35 requiredby.rpm
#
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Then, we issue the command:
After a few minutes, the command completes, and we take a look at the
files again:
# ls
total 3531
-rw-r--r-- 1 root root 1351680 Oct 17 20:50 fileindex.rpm
-rw-r--r-- 1 root root 16384 Oct 17 20:50 groupindex.rpm
-rw-r--r-- 1 root root 16384 Oct 17 20:50 nameindex.rpm
-rw-r--r-- 1 root root 2339080 Oct 17 20:50 packages.rpm
-rw-r--r-- 1 root root 16384 Oct 17 20:50 providesindex.rpm
-rw-r--r-- 1 root root 16384 Oct 17 20:50 requiredby.rpm
#
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You'll note that packages.rpm decreased in size.
This is due to a side-effect of the --rebuilddb
option — While it is going through the database, it is getting
rid of unused portions of the database. Our example was performed on
a newly installed system where only one or two packages had been
upgraded, so the reduction in size was small. For a system that has
been through a complete upgrade, the difference would be more
dramatic.
Does this mean that you should rebuild the database every once in a
while? Not really. Since RPM eventually will make use of the holes,
there's no major advantage to regular rebuilds. However, when an
RPM-based system has undergone a major upgrade, it certainly wouldn't
hurt to spend a few minutes using --rebuilddb to
clean things up.
If you are already using RPM, the --initdb option
is one you'll probably never have to use. The
--initdb option is used to create a new RPM
database. That's why you'll probably not need it if you're already
using RPM — you already have an RPM database.
It might seem that the
--initdb option would be
dangerous. After all, won't it trash your current database if you
mistakenly use it? Fortunately, the answer is no. If there is an RPM
database in place already, it's still perfectly safe to use the
option, even though it won't accomplish much. As an example, here's a
listing of the files that make up the RPM database on a Red Hat Linux
system:
# ls /var/lib/rpm
total 3559
-rw-r--r-- 1 root root 16384 Jan 8 22:10 conflictsindex.rpm
-rw-r--r-- 1 root root 1351680 Jan 8 22:10 fileindex.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 groupindex.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 nameindex.rpm
-rw-r--r-- 1 root root 2349640 Jan 8 22:10 packages.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 providesindex.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 requiredby.rpm
#
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Next, let's use the
--initdb option, just to see
what it does to this database:
# rpm --initdb
# ls /var/lib/rpm
total 3559
-rw-r--r-- 1 root root 16384 Jan 8 22:10 conflictsindex.rpm
-rw-r--r-- 1 root root 1351680 Jan 8 22:10 fileindex.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 groupindex.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 nameindex.rpm
-rw-r--r-- 1 root root 2349640 Jan 8 22:10 packages.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 providesindex.rpm
-rw-r--r-- 1 root root 16384 Jan 8 22:10 requiredby.rpm
#
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Since an RPM database existed already, the --initdb
option did no harm to it — there was no change to the database
files.
The only other option that can be used with
--initdb is --dbpath. This
permits the easy creation of a new RPM database in the directory
specified with the --dbpath option.
RPM includes a concise built-in help message for those times when you
need a reminder about a particular command. Normally you'll want to
use the
--help option by itself, though you might
want to pipe the output through a pager such as
less, since the output is more than one screen
long:
# rpm --help|less
RPM version 2.3
Copyright (C) 1995 - Red Hat Software
This may be freely redistributed under the terms of the GNU Public License
usage:
--help - print this message
--version - print the version of rpm being used
all modes support the following arguments:
--rcfile <file> - use <file> instead of /etc/rpmrc and $HOME/.rpmrc
-v - be a little more verbose
-vv - be incredibly verbose (for debugging)
-q - query mode
--root <dir> - use <dir> as the top level directory
--dbpath <dir> - use <dir> as the directory for the database
--queryformat <s> - use s as the header format (implies -i)
install, upgrade and query (with -p) allow ftp URL's to be used in place
of file names as well as the following options:
--ftpproxy <host> - hostname or IP of ftp proxy
--ftpport <port> - port number of ftp server (or proxy)
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This is just the first screen of RPM's help command. To see the rest,
give the command a try. Practically everything there is to know about
RPM is present in the --help output. It's a bit
too concise to learn RPM from, but it's enough to refresh your memory
when the syntax of a particular option escapes you.
