[lustre-devel] llmount.sh does not use fs-specific paths to the ost(s) and mds it mounts

[Quentin BOUGET]

Le 11/05/2016 03:17, Drokin, Oleg a écrit :
> On May 10, 2016, at 3:42 PM, Dilger, Andreas wrote:
>
>> On 2016/05/10, 08:14, "Quentin BOUGET" <quentin.bouget.ocre at cea.fr> wrote:
>>> Hello!
>>>
>>> While trying to mount two different lustre filesystems on a local node
>>> with the "llmount.sh" script, I noticed that the path to mount mds and
>>> ost(s) was computed like this:
>>>
>>> eval mntpt=${!var:-${MOUNT%/*}/$facet} # var is not defined by default,
>>> so this removes
>>>                                                                     #
>>> everything after the last '/' of $MOUNT
>>>
>>>
>>> The code can be found at test-framework.sh in the function "facet_mntpt"
>>> around the line 3226.
>>>
>>>
>>> By default MOUNT is initialized like this:
>>>
>>> MOUNT=${MOUNT:-/mnt/${FSNAME}} # default: "/mnt/lustre"
>>>
>>>
>>> Thus the default mountpoints for mds and ost(s) are "/mnt/mds1" and
>>> "/mnt/ost1".
>>> Because of that, when trying to do two successive calls to "llmount.sh"
>>> with two different values for FSNAME, the second fs to be mounted will
>>> unmount the first's mds and ost(s) (paths are identical).
>>>
>>>
>>> Is there any reason to truncate the MOUNT variable like this ? Shouldn't
>>> the mountpoint path look more like "/mnt/<fsname>-mds1" and
>>> "/mnt/<fsname>-ost1"?
>> I don't think there is any particular reason it was implemented this way,
>> just that it has worked for many years without the need to include the
>> fsname into the MDT/OST mount points... :-)
>>
>> If you want to expand it to allow exporting multiple filesystems from the
>> same MDS/OSS nodes then your suggestion to use $FSNAME-$facet in
>> facet_mntpt() is reasonable.  Please submit a patch to verify this is
>> working correctly.  There may be some places in the tests that aren't
>> using facet_mntpt() yet.
> I guess to expand on this, since llmount.sh is primarily a testing
> infrastructure and typically only one filesystem at a time is tested,
> the more than one mountpoint was never bothering anyone till you
> discovered this bit, I guess.
>
> Bye,
>      Oleg
>
>
Ok, thank you. I will submit a patch about it.

Bye,
     Quentin