[OpenAFS] Re: bos blockscanner

Jason Edgecombe jason@rampaginggeek.com
Sat, 26 Jan 2013 13:21:00 -0500

On 01/26/2013 12:06 PM, Hartmut Reuter wrote:
> Jason Edgecombe wrote:
>> On 01/26/2013 04:50 AM, Hartmut Reuter wrote:
>>> When OpenAFS started in 2000 I pushed a lot of extensions into it to make it
>>> easier to maintain MR-AFS. I think at that time we already were the last site to
>>> use it. The next years the source code of MR-AFS could be reduced to the very
>>> specific parts on the server side while with these extensions for all other
>>> subdirectories simply the openafs code could be used.
>>> The scanner was a stand alone program which traversed the volume metadata to
>>> find out which files needed to get a copy elsewhere and which files were
>>> eligible for wiping (removing from disk). In extreme situations it could be
>>> helpful to stop the scanner...
>>> There are many other remains of MR-AFS in different source files of openafs
>>> which savely could be removed now that MR-AFS is out of service since five years.
>>> MR-AFS was shutdown finally in 2008. Since than we are running AFS/OSD which has
>>> a all the features MR-AFS had and some more. I am working on the project to
>>> bring the AFS/OSD change into the official openafs source code.
>>> -Hartmut
>>> Andrew Deason wrote:
>>>> On Fri, 25 Jan 2013 19:50:41 +0100 (CET)
>>>> Thorsten Alteholz <openafs@alteholz.de> wrote:
>>>>> the command 'bos help' says something about 'blockscanner' and
>>>>> 'unblockscanner'.  This shall start something like
>>>>> '/usr/afs/bin/scanner -block'. But I did not find anything about such
>>>>> scanner. Can anybody please shed some light on this? Is this a new
>>>>> fearture for the future?
>>>> No, it is very old. I believe that is there to accommodate installations
>>>> with MR-AFS. MR-AFS is for using AFS with HSM systems but is not freely
>>>> available or open source or anything; you can google around for what
>>>> little information exists about it. I'm not sure if it's still in use.
>>>> Those rpcs hard code the commands they run, ugh...
>>>> I don't have any familiarity with it, but from what I've seen in the
>>>> OpenAFS source, I think the 'scanner' process is something that shuffled
>>>> data between disk and tape. Normally it runs continuously or something,
>>>> but those commands allow you to temporarily disable or enable
>>>> migrations.
>> Should the blockscanner feature be removed?
> Yes and much more: the type fs allows to run the scanner and bos salvage has
> many options which are only mr-afs specific...
> Hartmut

what does the rest of the list think?