Bug#471699: lvm2: restrictions in validate_name are not documented in lvcreate manpage

[Tim Connors]

Package: lvm2
Version: 2.02.33-2
Severity: normal

Trying to encode a human readable date format in a snapshot, lead to
the following error message:

> lvcreate -L1G -s -n '2008-03-20:01:51:45'-shared_home_etc-snapshot /dev/laptop_250gb/shared_home_etc
  Logical volume name "2008-03-20:01:51:45-shared_home_etc-snapshot" is invalid
  Run `lvcreate --help' for more information.

I tried a few things other than ":", which many characters failing.  I
fell back to RTFM to find what the restrictions on names were, but
alas, none are documented.  RTFS revealed validate_name() and
apply_lvname_restrictions() -- perhaps the allowable characters[1]
need to be listed in the manpage and in the --help documentation (as
it hints that more information on the failure ought to be there)?

[1] alphanumeric, or '.', '_', '-', '+'.  No "snapshot", "pvmove",
"_mlog", or "_mimage" in the name.

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.24 (SMP w/2 CPU cores)
Locale: LANG=en_AU, LC_CTYPE=en_AU (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/bash

Versions of packages lvm2 depends on:
ii  libc6                        2.7-9       GNU C Library: Shared libraries
ii  libdevmapper1.02.1           2:1.02.24-4 The Linux Kernel Device Mapper use
ii  libreadline5                 5.2-3       GNU readline and history libraries

lvm2 recommends no packages.

-- no debconf information