CIFS symbolic link behaviour

[Jean-Baptiste Denis]

Hi,

I've got two isilon clusters A and B. Cluster A is running OneFS 7.1.0.1 and
cluster B is running 7.1.1.1.

On A :

A# uname -v
Isilon OneFS v7.1.0.1 B_7_1_0_34(RELEASE): 0x701005000100022:Wed Jan 29 20:31:45
PST 2014
ro...@fastbuild-02.west.isilon.com:/build/mnt/obj.RELEASE/build/mnt/src/sys/IQ.amd64.release
A# mkdir foo && ln -s foo foolink
A# chown -h -R jbdenis:sis .
A# find . -ls
5191175329 4 drwxr-xr-x 3 jbdenis sis 46 Dec 29 18:12 .
5200135528 4 drwxr-xr-x 2 jbdenis sis 0 Dec 29 18:12 ./foo
5192945682 3 lrwxr-xr-x 1 jbdenis sis 3 Dec 29 18:12 ./foolink -> foo

If I access this directory using CIFS, a windows 7 client see "foolink" as a
classic directory and I've got no problem to open it. (Awin7.png screenshot).

I perform the exact same things on cluster B (running 7.1.1.1) :

B# uname -v
Isilon OneFS v7.1.1.1 B_7_1_1_84(RELEASE): 0x701015000100054:Thu Sep 18 15:11:08
PDT 2014
ro...@fastbuild-06.west.isilon.com:/build/mnt/obj.RELEASE/build/mnt/src/sys/IQ.amd64.release
B# mkdir foo && ln -s foo foolink
B# chown -h -R jbdenis:sis .
B# find . -ls
6663167733 5 drwxr-xr-x 3 jbdenis sis 46 Dec 29 18:20 .
6663885610 5 drwxr-xr-x 2 jbdenis sis 0 Dec 29 18:20 ./foo
6663167734 4 lrwxr-xr-x 1 jbdenis sis 3 Dec 29 18:20 ./foolink -> foo

If I access this directory using CIFS, the same windows 7 client as before see
"foolink" as a shortcut file (Bwin7.png screenshot).

Sure, you can play with "fsutil behaviour set SymlinkEvaluation"
(http://blogs.msdn.com/b/junfeng/archive/2012/05/07/the-symbolic-link-cannot-be-followed-because-its-type-is-disabled.aspx)

to allow remote to remote links, but that's not what I'm interested about here
(not regarding the fact that enabling the remote to remote links just work one
time. Once you've entered the directory, the explorer is interpreting the link
as a file)...

Multiple users are complaining here that we've broke their workflow since the
upgrade of cluster B from 7.0.2.7 to 7.1.1.1 :(

I've read the Release Notes for the 7.1.1.1 release and spot this in the "known
issues and limitations section" :

138049 SMB

If a symbolic link to a directory ends with a forward
slash (/), SMB clients sometimes misidentify the
directory as a file. If this occurs, the directory cannot
be opened though the symbolic link.

Looks related, but that not what I'm observing.

Is there a way to have old behaviour back ?

Of course I've opened a case, but I'm still waiting for an answer =)

Jean-Baptiste

[erik.j...@gmail.com]

Have the case owner check EMC KB 193808

--
Erik Weiman
Sent from my iPhone 5s

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<Awin7.png>
<Bwin7.png>

[Jean-Baptiste Denis]

In fact it looks like this known issue (from the Release notes file...) :

137701 SMB

If the SMB2Symlinks option is disabled on the
cluster and a Windows client navigates to a symbolic
link that points to a directory, under some
circumstances, the system returns incorrect
information about the symbolic link. If this occurs,
the symbolic link appears to be a file and the
referenced directory cannot be opened.

I don't known about the SMB2Symlinks, I'll wait for the support, hoping for a
patch or a solution.

Jean-Baptiste

[Jean-Baptiste Denis]

On 12/29/2014 06:58 PM, erik.j...@gmail.com wrote:
> EMC KB 193808

Thank you for the tip.

Jean-Baptiste

[Jean-Baptiste Denis]

On 12/29/2014 07:00 PM, Jean-Baptiste Denis wrote:
> On 12/29/2014 06:58 PM, erik.j...@gmail.com wrote:
>> EMC KB 193808

Support :

"Firstly, KB 193808 is exactly what I was going to recommend to you, though it
is not yet externally viewable. The command which it references is isi_gconfig
registry.Services.lwio.Parameters.Drivers.onefs.SMB2Symlinks=0. This command
(without quotes) can be run on any node in the cluster, and will change it on
all nodes."

It did the trick, thank you.

"This will disable the reporting of cluster-side symlinks as reparse points".

I don't know what a reparse point is; so I've asked for some explanations and
what motivates the change of the default setting.

Thank you !

Jean-Baptiste