Fwd: [OpenAFS] mmap issue?

Derrick Brashear shadow@gmail.com
Fri, 23 Mar 2012 16:13:26 -0400

since i blew it and didn't reply-all earlier...

---------- Forwarded message ----------
From: Derrick Brashear <shadow@gmail.com>
Date: Fri, Mar 23, 2012 at 3:00 PM
Subject: Re: [OpenAFS] mmap issue?
To: ecgarris@iu.edu

On Fri, Mar 23, 2012 at 2:52 PM, Eric Chris Garrison <ecgarris@iupui.edu> w=
> Hello,
> I've had a complaint from one of our users. =A0He says:
> "I just had afs do a very very nasty thing to me. =A0 I ran a program on
> a data file and for some unknown reason the file was totally corrupted
> after running this program. =A0 I can absolutely certify that the problem
> is not the program itself because I ran exactly the same program on a
> local disk and it did what I was asking it to do without corrupting the
> file.
> I suspect strongly this problem is created by memory mapping of the file
> which I think this program is implicitly using. =A0 The actual thing I wa=
> running was a perl script, but it was calling programs I am pretty sure
> do memory mapping for io speed."
> I asked him for details, and he is using code that uses this:
> "I was running a program in the "Antelope" package sold by brtt.com.
> The particular program is a perl script called dbfix_calib. However, the
> offender is almost certainly this line
> system( "dbjoin $dbname.$table calibration | dbset -v - $table.calib
> 'calib =3D=3D NULL' calibration.calib" );"
> He is running OpenAFS 1.5.77 for MacOS 10.6.8, and our servers are at
> 1.4.14-1.1.1.

The server's not an issue here (if you'd said 1.6.0 I'd have told you
you wanted 1.6.1pre4)

That macos client is ancient and i haven't got a clue what bugs it might ha=

If you can give me a test I am happy to verify behavior in a current build.

> I've searched for this, and it appears mmap operations used to be a
> problem. =A0At what version of OpenAFS (server and client) should we be a=
> for this to not be a problem?
> Thank you,
> Chris
> --
> Eric Chris Garrison | Principal Mass Storage Specialist
> ecgarris@iu.edu =A0 =A0 | Indiana University - Research Storage
> 317-278-1207 =A0 =A0 =A0 =A0| Jabber IM: ecgarris@iupui.edu