Re: [OSR-devel] /etc/mtab

[Gordan B. <go...@bo...>]

Marc Grimme wrote:

>> The reason I ask two-fold:
>>
>> 1) I'm not sure if having it symlinked to /proc/mounts confuses the 
>> process of unmounting the file systems in the shared root during 
>> shutdown. /proc/mounts shows all mounted file systems, including paths
>>
>> that aren't mounted in the OSR root (e.g. /mnt/tmproot for the glfs 
>> backing fs is mounted only in the initroot, but still shows up in 
>> /proc/mounts).
>>
>> 2) It seems to interfere with the checks to see whether a bind-mount
>> is 
>> already mounted. Under OSR, I'm seeing all bind-mounts in fstab
>> getting 
>> mounted twice, once when mounting local file systems, and once when 
>> mounting "other" file systems.
 >
> This can be changed. Just add an options _netdev as option to the fstab an the bindmounts should only be mounted once.

I thought about that, but it's a bit of a bodge. It can end up 
interfering with the unmounting order on shutdown since it makes all of 
those file systems unmount via the netfs init script rather than halt.

>> Is anything likely to break if /etc/mtab is symlinked to 
>> /cdsl.local/etc/mtab?
> Yes.
> First see:
> https://partner-bugzilla.redhat.com/show_bug.cgi?id=214891
> Then when mount <path> is executed with RHEL5 the following is done (if I recall it right).
> All changes are done to a tmpfile /etc/mtab.tmp and this version gets newly created in /etc and afterwards copied back to /etc/mtab. The symlink to /cdsl.local does not survive. But if /etc/mtab is a symlink to /proc/mounts all of the above is ignored.
> 
> That's how I recall the background of this topic.
> 
> As this is in phase of being change it might be that there are changes already in RHEL5 latest U but not very likely.

I see. That is, indeed a problem. :-/
Of course, going to OpenVZ guest root as mentioned in my other post 
would work around this (if it works at all, but that's something I'm 
planning to find out relatively soon).
*whistles innocently* ;)

Gordan