--- Begin Message ---
|
Subject: |
Possible bug for df |
|
Date: |
Wed, 09 Mar 2011 02:36:31 -0700 |
|
User-agent: |
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.17) Gecko/20110123 SeaMonkey/2.0.12 |
The "df" tool will mismatch mounted devices when a specific device
parameter is specified.
Here's some console output from running df;
[/var/log]
address@hidden>df -h /dev/md5
Filesystem Size Used Avail Use% Mounted on
/dev/md5 2.3T 1.7T 534G 76% /mnt/backup/bak5
[/var/log]
address@hidden>df -h /dev/md5
Filesystem Size Used Avail Use% Mounted on
udev 881M 372K 880M 1% /dev
In the second invocation, the /dev/md5 device had been dismounted, but
the /dev filesystem is now being matched, when it should not be.
Expected behavior is to get non-zero exit code and print nothing, and/or
an error on stderr that the device is not found.
Note that this was to be used in a script. I tried with the -P flag,
and the behavior is the same, in that the wrong mount is matched.
address@hidden>df --version
df (GNU coreutils) 8.5
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Torbjorn Granlund, David MacKenzie, and Paul Eggert.
Also FYI
address@hidden>df -v
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/sor--vg1-root
8256952 3884136 4288932 48% /
tmpfs 906132 4 906128 1% /lib/init/rw
udev 901260 372 900888 1% /dev
tmpfs 906132 4 906128 1% /dev/shm
/dev/md0 241036 108803 107344 51% /boot
/dev/mapper/sor--vg1-tmp
2064208 71112 1888240 4% /tmp
/dev/mapper/sor--vg1-var
1906616172 621163644 1266103904 33% /var
/dev/mapper/sor--vg1-var--log
4128448 2038268 2090180 50% /var/log
No reply needed. Sorry if this is duplicate or expected behavior.
--
# Jesse Molina
# Mail = address@hidden
# Page = address@hidden
# Cell = 1.602.323.7608
# Web = http://www.opendreams.net/jesse/
--- End Message ---
--- Begin Message ---
|
Subject: |
Re: bug#8208: Possible bug for df |
|
Date: |
Wed, 09 Mar 2011 16:20:54 +0000 |
|
User-agent: |
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 |
On 09/03/11 09:36, Jesse Molina wrote:
>
> The "df" tool will mismatch mounted devices when a specific device
> parameter is specified.
>
> Here's some console output from running df;
>
> [/var/log]
> address@hidden>df -h /dev/md5
> Filesystem Size Used Avail Use% Mounted on
> /dev/md5 2.3T 1.7T 534G 76% /mnt/backup/bak5
> [/var/log]
> address@hidden>df -h /dev/md5
> Filesystem Size Used Avail Use% Mounted on
> udev 881M 372K 880M 1% /dev
>
>
>
> In the second invocation, the /dev/md5 device had been dismounted, but
> the /dev filesystem is now being matched, when it should not be.
>
> Expected behavior is to get non-zero exit code and print nothing, and/or
> an error on stderr that the device is not found.
>
> Note that this was to be used in a script. I tried with the -P flag,
> and the behavior is the same, in that the wrong mount is matched.
This is expected behavior. If the passed file is not a mount point itself,
df will go and find it's mount point, and report for that device.
If you want to enforce that the passed device node is mounted
then I suggest you ensure that the file system is the same as passed, like:
dev=/dev/md5
df_dev=$(df -P $dev | sed -n '2s/\([^ ]*\).*/\1/p')
test "$dev" = "$df_dev" || { echo "$dev not mounted" >&2; exit 1; }
cheers,
Pádraig.
--- End Message ---