News and Announcements

11-April-2014 - noric and yakut aliases being removed on 5-May-2014

On 5-May-2014, the noric and yakut aliases will be removed.

Please use the following names to access the compute interactive login machines:

rhel5-32
rhel5-64
rhel6-32
rhel6-64

It was previously announced on comp-change that the noric alias would be
moved from rhel5-32 to rhel6-64.  However, at the latest quarterly Town Hall
Meeting for Unix Services, there was a request from the community to simply
remove the old aliases to avoid confusion.

24-March-2014 - Turning off authenticated ftp on ftp.slac.stanford.edu

Authenticated (as opposed to anonymous) FTP generally sends a clear-text account name and
password across the network making it one of the least secure protocols still in use today.
We need to phase out the use of authenticated FTP as soon as we can.

Anonymous FTP does not by its nature expose passwords, and is not a target of this phase out.

The first phase of this process occurred a number of years ago when we restricted FTP
connections from offsite to a small set of approved FTP servers (those with hostnames
beginning with "ftp"), and set the default configuration for newly installed Linux
systems to disable FTP service.

Secure alternatives include scp, sftp, rsync via ssh, bbcp, bbftp, and direct copy using
the AFS client on Windows, Macs, or UNIX systems. UNIX users can find more information
about most of these programs from their man pages. Windows users can find information
about WinSCP, a popular scp client program for Windows, at https://xweb.slac.stanford.edu/.

29-January-2014 - Subnet Router reconfiguration work scheduled for 30 January 2014, 2-3pm PST.

SLAC IT Network Engineering will be doing some router reconfiguration on Thursday, 30 January 2014 from 2pm-3pm PST.  There will be a 20 second outage on each subnet during the reconfiguration.  However, there is no anticipated impact on services or applications.  Network Engineering and Unix Admin will be monitoring hosts, the network, and services during this work.

If you do notice any problems, please notify unix-admin@slac.stanford.edu right away.

The following single page lists all hosts which are connected to the subnets being reconfigured (you can quickly grep or find hosts you are interested in):
http://www.slac.stanford.edu/comp/unix/news/2014-Jan-30-subnet-reconfig.txt

The subnets being reconfigured are below.

VLAN 16   NETHUB            http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=16
VLAN 174  NETHUB-IFZ-LITE   http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=174
VLAN 175  NETHUB-IFZ        http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=175
VLAN 831  SERV01-PRIVATE    http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=831
VLAN 844  SERV01-SEC-PRIV   http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=844
VLAN 846  SERV01-CONSOLE    http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=846
VLAN 847  SERV01-DHCP       http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=847
VLAN 880  SERV01-SEC-PRIV02 http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=880
VLAN 890  SERV01-NS-MASTER  http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=890
VLAN 1412 SERV01-LOGIN      http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1412
VLAN 1418 SERV01-IFZLITE    http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1418
VLAN 1432 SERV01-SMTP       http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1432
VLAN 1433 SERV01-CPP-SENSOR http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1433
VLAN 1441 SERV01-IEPM       http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1441
VLAN 1445 SERV01-SEC-LITE   http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1445
VLAN 1464 SERV01-NS-INT     http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1464
VLAN 1466 SERV01-NS-EXT     http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1466
VLAN 1808 SERV01-PUBLIC     http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1808
VLAN 1812 SERV01-AFS        http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1812
VLAN 1814 SERV01-WEBSERV    http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1814
VLAN 1848 WINLB1            http://www-lanmon.slac.stanford.edu/reports.cgi?rm=hosts&layer=vlan&param=1848

21-January-2014 - NFS bug in some RHEL6 kernels

There is a bug in some later RHEL6 kernels which can cause data corruption under some specific scenarios. 

There is an open bugzilla and upstream kernel patch.  RH is working with upstream to get the patch included, after which time an updated kernel RPM will be released.   We have reverted the batch cluster to a backlevel kernel which does not have this bug.  Let us know if you have any questions or concerns.

8-January-2014 - SU-HPC seminar at Stanford: OpenMP 4.0

OpenMP 4.0, Michael Klemm, Intel
Thursday, January 23, 3:30 - 5pm, Spilker 232 (Stanford University)

Abstract: OpenMP 4.0 is the current release of the OpenMP API specification. It added new major features to the OpenMP language to incorporate latest technological trends in HPC and beyond. The new features will significantly increase the expressiveness of OpenMP and its applicability for complex HPC codes. In this presentation, we will provide an in-depth overview of the new features. The presented features include user-defined reductions, support for SIMD instructions, support for accelerators/coprocessors, and affinity.

Bio: Michael Klemm is part of Intel's Software and Services Group, Developer Relations Division. His focus is on High Performance and Throughput Computing. Michael holds a Doctor of Engineering degree (Dr.-Ing.) in Computer Science from the Friedrich-Alexander-University Erlangen-Nuremberg, Germany. Michael's areas of interest include compiler construction, design of programming languages, parallel programming, and performance analysis and tuning. Michael is Intel representative in the OpenMP Language Committee and leads the efforts to develop error handling features for OpenMP.

20-December-2013 - TotalView

The Computing Division is currently paying more than $2.5K for software maintenance and support for the TotalView product. The license allows 256 concurrent users, however, according to our logs, we are using much less than that number.   We would like to understand the actual demand for TotalView by our community so that we can explore options, such as decreasing our license count.  

Please let us know how critical this software is for your research, how often you use it, and what the impact would be if it were not available. 

In January 2014, we will contact current TotalView users to gather information for planning and budgeting purposes.

19-December-2013

After the first Town Hall for Unix Services, we have created a mailing list to increase communications between the Unix Community and SCS.
The list is unix-community@slac.stanford.edu

We have already added some people to the list.  You can see if you are already subscribed on this web page
(and also manage your subscription):   

https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=UNIX-COMMUNITY&A=1

To subscribe to the list via email, send an email to:  listserv@slac.stanford.edu   with subscribe request in BODY as follows: 
subscribe unix-community

If you are already subscribed, you will get a response back letting you know that.

    $ echo subscribe unix-community | mail  listserv@slac.stanford.edu

19-December-2013

RHEL 7

A dedicated page for RHEL7 news and updates has been created.
https://confluence.slac.stanford.edu/display/SCSPub/RHEL+7

5-December-2013

GNU Fortran 4.8.1 is now installed on the bullet cluster and the RHEL6-64 norics.
Usage:

            $ scl enable devtoolset-2 'gfortran ...'

            or

            $ scl enable devtoolset-2 'bash'

            $ gfortran ...

26-November-2013

Red Hat Enterprise 5 and 6 reboots will be required to enable the latest security-patched kernel.
Details to follow...

21-November-2013

RHEL 6.5 released
https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html-single/6.5_Release_Notes/index.html

20-November-2013

Red Hat offers two relatively new products which may be of interest to the SLAC community:
Software Collections: http://developerblog.redhat.com/2013/09/12/rhscl1-ga/
Developer Toolset: http://developerblog.redhat.com/2013/09/12/rh-dts2-ga/

Please send email to unix-admin@slac.stanford.edu if you are interested in using these.