[OpenAFS] vos examine oddity

[Dexter Kimball]

Right, the last part is the VLDB entry (vos listvldb, identical).


The third line (after the line with the prompt, below) is the one that I
thought was odd:

[kim@angel kim]$ vos exa root.afs.readonly
root.afs.readonly                 536901459 RO         10 K  On-line   <<<<
    magic.lab.ccre.com /vicepa
    RWrite  536901458 ROnly          0 Backup          0               <<<<
    MaxQuota       5000 K
    Creation    Fri Jan 28 08:03:29 2005
    Last Update Fri Jan 28 08:03:29 2005
    0 accesses in the past day (i.e., vnode references)


Jeffrey Hutzelman has clarified things nicely in his other email.  Jeffrey,
I rephrase here to see if I got it:

First line, " root.afs.readonly                 536901459 RO         10 K
On-line  " , refers specifically to the volume being examined, saying in
effect "This particular volume is a type RO volume with volID 536901459"

Second line is location " magic.lab.ccre.com /vicepa" 

What Jeffrey clarifies is that the next line is _not_ about the specific
volume being examined, but instead gives information about the volume
"family" of which this volume is a member.

So " RWrite  536901458 ROnly          0 Backup          0     "

reads 

I have a parent RW, ID 536901458.
I, the RO volume, am not replicated.  (There may be other replicas like me,
but I myself am not the source/parent of any replica)
I, the RO volume, do not have a corresponding Backup volume (My parent RW
may have a Backup volume, but I am not the source/parent of any Backup
volume)

Which is very interesting and informative.

Thanks much Jeffrey and Russ.  Nothing like another detail to chew on.

I particularly like the RO restore example, where the RO is its own parent
-- i.e. not parented by a RW as is the predominant case.

Kim



> -----Original Message-----
> From: openafs-info-admin@openafs.org 
> [mailto:openafs-info-admin@openafs.org] On Behalf Of Russ Allbery
> Sent: Friday, January 28, 2005 2:22 PM
> To: openafs-info@openafs.org
> Subject: Re: [OpenAFS] vos examine oddity
> 
> 
> Dexter 'Kim' Kimball <dhk@ccre.com> writes:
> 
> > In this case I'm explicitly examining an RO.  The ID of the RO is
> > correctly reported 536901459 on the <volume name> line -- 
> but in that
> > same record two lines down the RO volID is "0"
> 
> > So apparently vos exa does know the RO volID (first line) 
> but it doesn't
> > get printed (third line) because (beats me ... called from different
> > routine?  gets reset somewhere after it's first populated? elves?)
> 
> Yeah, this is the same issue.  The reason why the last part 
> is correct is
> that that information is coming from the VLDB instead of the 
> volserver.
> It looks like the volserver sometimes doesn't know that there's a RO.
> 
> I'm going to file a bug with the OpenAFS bug tracker.  It's 
> not a big deal
> for us, as I can still do what I needed to do by inverting 
> the sense of my
> query (look for ROs and then find their RWs via the RWrite part, which
> appears to always be okay).
> 
> -- 
> Russ Allbery (rra@stanford.edu)             
> <http://www.eyrie.org/~eagle/>
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