[Pvfs2-users] Is there a way to prevent MPI-ROMIO access?

[Bill Wichser]

Sam Lang wrote:
> 
> On Aug 31, 2007, at 11:55 AM, Bill Wichser wrote:
> 
>> Murali,
>>
>> Thanks, that's the right command.  Now that I see it I even remember 
>> using it in the past, wrapped around the pvfs2-fsck!
>>
>> We actually have a system reservation set for Monday morning so once 
>> the jobs in the queue trickle down, we'll be able to start the fsck.
> 
> pvfs2-fsck sets the admin mode before running, and puts it back to 
> normal mode once its done.
> -sam

Thanks for this information.  This is something I certainly didn't know.

Bill


>> Murali Vilayannur wrote:
>>> Hi Bill,
>>> One way to do this is to switch the server to admin mode. I think you
>>> can do that using pvfs2-set-mode in src/apps/admin.
>>> After that the server won't take regular requests I think..
>>> I don't know if the fsck app already does that..You will of course
>>> need to switch the mode back after the fsck finishes...
>>> It has been a while since I looked at that code.. so I could be 
>>> wrong.. :)
>>> It would be best if you ask all users to kill their jobs before 
>>> running fsck..
>>> Online fsck is probably going to cause a lot of grief if users are
>>> actively using
>>> the volume...
>>> thanks,
>>> Murali
>>> On 8/31/07, Bill Wichser <bill at princeton.edu> wrote:
>>>> We'd finally like to run an fsck to try and clean up our pvfs2
>>>> filesystem (see my previous post about kernel crashes) but are 
>>>> concerned
>>>> about users' jobs still accessing the filesystem while we are running
>>>> these checks.
>>>>
>>>>  From the kernel interface, this is easy, we simply disable the kernel
>>>> module.  The other method though, direct access via the API/MPI-ROMIO,
>>>> remains an issue.  Is there some method we can use to disable access
>>>> through this interface?  Or can we just run the fsck without worrying
>>>> about this?
>>>>
>>>> Thanks,
>>>> Bill
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>