To mount or not to Mount proc, that is the question
I've been trying to debug a problem where one laptop's networking, as
controlled by wicd, seems to randomly go offline once in awhile. In
the process of reviewing 5 machines I ran across an inconsistency
across a bunch of my machines, new and old. It seems some of them
mount proc in fstab while others do not. Some of these machines have
been around for a few years not mounting proc and except for the
laptop's networking issues there really haven't been any problems.
To mount or not to Mount proc, that is the question
On Fri, Mar 16, 2012 at 1:40 PM, Mark Knecht <markknecht@gmail.com> wrote:
> I've been trying to debug a problem where one laptop's networking, as
> controlled by wicd, seems to randomly go offline once in awhile. In
> the process of reviewing 5 machines I ran across an inconsistency
> across a bunch of my machines, new and old. It seems some of them
> mount proc in fstab while others do not. Some of these machines have
> been around for a few years not mounting proc and except for the
> laptop's networking issues there really haven't been any problems.
>
> Looking at the Gentoo amd64 install guide here:
>
> http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=8
>
> it appears that the recommendation is to mount proc.
>
> [quote]
>
> /dev/sda1 * /boot * * * *ext2 * *defaults,noatime * * 1 2
> /dev/sda2 * none * * * * swap * *sw * * * * * * * * * 0 0
> /dev/sda3 * / * * * * * *ext3 * *noatime * * * * * * *0 1
>
> /dev/cdrom */mnt/cdrom * auto * *noauto,user * * * * *0 0
>
> proc * * * */proc * * * *proc * *defaults * * * * * * 0 0
> shm * * * * /dev/shm * * tmpfs * nodev,nosuid,noexec *0 0
>
> [quote]
>
>
> What would the issues be with proc not mounted? For instance, this
> machine doesn't mount proc in fstab but still has proc:
>
> laptop1 ~ # cat /etc/fstab
> <SNIP>
> /dev/sdb1 * * * * * * * /boot * * * * * ext2 * * * * * *noauto,noatime *1 2
> /dev/sdb4 * * * * * * * / * * * * * * * ext3 * * * * * *noatime * * * * 0 1
> /dev/sdb2 * * * * * * * none * * * * * *swap * * * * * *sw * * * * * * *0 0
> /dev/cdrom * * * * * * */mnt/cdrom * * *auto * * * * * *noauto,ro * * * 0 0
>
> shm * * * * * * * * * * /dev/shm * * * *tmpfs
> nodev,nosuid,noexec * * 0 0
>
>
> laptop1 ~ # cat /proc/mdstat
> Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
> md127 : active (auto-read-only) raid1 sdb3[1] sda3[0]
> * * *343758245 blocks super 1.2 [2/2] [UU]
>
> unused devices: <none>
> laptop1 ~ #
I haven't put /proc explicitly on my /etc/fstab since a long time ago,
and everything seems to be working. However, I use systemd, which
always mounts /proc with the default options, and only uses the entry
in /etc/fstab (if present) to override the default options. In other
words, systemd always mounts /proc, no matter if it's listed in
/etc/fstab or not.
I don't know what OpenRC does, but it would not surprise me that it's
something similar.
Regards.
--
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México
03-16-2012, 08:18 PM
Mark Knecht
To mount or not to Mount proc, that is the question
On Fri, Mar 16, 2012 at 12:47 PM, Canek Peláez Valdés <caneko@gmail.com> wrote:
> On Fri, Mar 16, 2012 at 1:40 PM, Mark Knecht <markknecht@gmail.com> wrote:
<SNIP>
>> Looking at the Gentoo amd64 install guide here:
>>
>> http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=8
>>
>> it appears that the recommendation is to mount proc.
>>
>> [quote]
>>
>> /dev/sda1 * /boot * * * *ext2 * *defaults,noatime * * 1 2
>> /dev/sda2 * none * * * * swap * *sw * * * * * * * * * 0 0
>> /dev/sda3 * / * * * * * *ext3 * *noatime * * * * * * *0 1
>>
>> /dev/cdrom */mnt/cdrom * auto * *noauto,user * * * * *0 0
>>
>> proc * * * */proc * * * *proc * *defaults * * * * * * 0 0
>> shm * * * * /dev/shm * * tmpfs * nodev,nosuid,noexec *0 0
>>
>> [quote]
<SNIP>
>
> I haven't put /proc explicitly on my /etc/fstab since a long time ago,
> and everything seems to be working. However, I use systemd, which
> always mounts /proc with the default options, and only uses the entry
> in /etc/fstab (if present) to override the default options. In other
> words, systemd always mounts /proc, no matter if it's listed in
> /etc/fstab or not.
>
> I don't know what OpenRC does, but it would not surprise me that it's
> something similar.
>
> Regards.
> --
> Canek Peláez Valdés
> Posgrado en Ciencia e Ingeniería de la Computación
> Universidad Nacional Autónoma de México
>
Thanks Canek. I appreciate your response.
It seems when rereading the link above the authors do put the work
'example' in italics, implying that possibly I should know what I'm
doing and not depend on the text on that page. I'm fine with the not
depending part. I'm not so sure about the 'know what I'm doing' part.
;-)
I'm going to take a wild guess that it's somehow mounted in an init
script these days but I have no reason to know that's actually how it
gets done. I did read the kernel docs and it doesn't seem to be done
automatically by the kernel AFAICT.