[OpenAFS] RE: [OpenAFS-announce] OpenAFS client crashes on RHEL 5.10 and RHEL 6.5

Dave B. botsch@cnf.cornell.edu
Fri, 07 Mar 2014 18:29:59 -0500


and Oel, which gives you a choice of RHEL-compatible or mainline

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On March 7, 2014 4:31:04 PM Jeffrey Altman <jaltman@secure-endpoints.com>=
=20
wrote:

> To the extent that Centos releases are slightly modified RHEL5 and RHEL=
6
> releases rebranded, the behavior is the same.
>
> On 3/7/2014 4:18 PM, Devine, Steven wrote:
> > Is there any data on this behaviour on CentOS ?
> > Steve Devine
> > Michigan State University
> >
> > ________________________________________
> > From: openafs-announce-admin@openafs.org=20
> [openafs-announce-admin@openafs.org] on behalf of Andrew Deason=20
> [adeason@sinenomine.net]
> > Sent: Friday, March 07, 2014 11:03 AM
> > To: openafs-announce@openafs.org
> > Cc: openafs-info@openafs.org
> > Subject: [OpenAFS-announce] OpenAFS client crashes on RHEL 5.10 and R=
HEL 6.5
> > It has been discovered that the OpenAFS client interacts poorly with =
a
> > change to the Linux kernel introduced in Red Hat Enterprise Linux
> > versions 5.10 and 6.5, which can cause a kernel panic with certain AF=
S
> > access patterns. Sites may want to exercise caution when considering
> > upgrading RHEL systems that are running OpenAFS clients.
> > While the mechanism that is causing this problem is understood and a
> > solution is being developed, fixing this issue is not straightforward
> > and may take some time. In the meantime, without a fix in place, the
> > following workarounds may help avoid encountering the issue:
> >  - Avoid using multiple different mountpoints to access the same data=
,
> >    since this can confuse the Linux VFS in some situations. This may =
be
> >    difficult to guarantee (since /afs/cellname and /afs/.cellname
> >    usually exist), but it may be possible to reduce such mountpoint
> >    usage in some scenarios.
> >  - Avoid running the RHEL 5.10 kernel or the RHEL 6.5 kernel on machi=
nes
> >    with OpenAFS clients. However, these kernel updates contain stabil=
ity
> >    and security fixes, so it may not be desirable to avoid upgrading
> >    such machines running OpenAFS clients.
> > Note that the RHEL 7 Beta is not affected by this issue, but it is no=
t
> > known if the final release of RHEL 7 will. No other distributions of
> > Linux are known to be affected by this (except any that are derived f=
rom
> > RHEL), and the problematic change to the Linux kernel is not in vanil=
la
> > upstream Linux kernel releases.
> > If your site has a support contract with Red Hat, you may wish to
> > inquire about this issue through your support channel. For reference,
> > the issue was introduced in RHEL5 in kernel 2.6.18-367.el5 with this
> > change:
> >  - [fs] vfs: stop d_splice_alias creating directory aliases (J. Bruce=
=20
> Fields) [785916]
> > and in RHEL6 in kernel 2.6.32-408.el6 with this change:
> >  - [fs] vfs: stop d_splice_alias creating directory aliases (J. Bruce=
=20
> Fields) [820446]
> > For more details and future updates on this issue, see this RT ticket=
:
> >=20
> <https://rt.central.org/rt/Ticket/Display.html?id=3D130273&user=3Dguest=
&pass=3Dguest>
> > --
> > Andrew Deason
> > adeason@sinenomine.net
> > _______________________________________________
> > OpenAFS-announce mailing list
> > OpenAFS-announce@openafs.org
> > https://lists.openafs.org/mailman/listinfo/openafs-announce
> > _______________________________________________
> > OpenAFS-info mailing list
> > OpenAFS-info@openafs.org
> > https://lists.openafs.org/mailman/listinfo/openafs-info
> >