Author: kittycool only

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CentOS Project is shifting to CentOS Stream

The CentOS project recently announced a shift in strategy for CentOS.

  • It will be shifting to an upstream build (testing patches and updates before inclusion in the upstream vendor).
  • Additionally, support for CentOS Linux 8 has been cut short, from May 31, 2029 to December 31, 2021.
  • CentOS 7 will continue to be supported as a downstream version of RHEL 7 till Jun 2024.

 

 

Where do we go from here? We can look at Rocky Linux. Rocky Linux aims to function as a downstream build as CentOS had done previously, building releases after they have been added by the upstream vendor, not before. Rocky Linux is led by Gregory Kurtzer, founder of the CentOS project.

 

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Power On and Booting the Server

Step 1: Logged in to your RMC

Step 2:  Check the state of the system. To view the partition configuration, enter show npar.

RMC cli> show npar pnum=0
RMC cli> show complex

If no errors are indicated, then proceed to power up the system.

If there are errors, run

RMC cli>show logs error

and resolve the errors before powering up the system.

Step 3: To power up the system, assuming it is configured with all chassis in one large nPartition numbered 0

RMC cli> power on npar pnum=0

References:

  1. HPE Superdome Flex Server – Powering ON and Booting the Server
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Powering Off SuperDome Flex System

Step 1: Power down the SuperDome Flex Server via OS

% shutdown -h now

Step 2: Log into the RMC as the administrator user, and enter the following command to power OFF the system:

RMC cli> power off npar pnum=0

To power RMC OFF a single partition, enter the following command:

RMC cli> power off npar pnum=x

Where x=nPar number.

If the above command is not workable, you may have to force power off

RMC cli> power off npar pnum=0 force

Step 3: Enter the following command, and verify that the Run State is OFF:

 RMC cli> show npar
 Partitions: 1
 Par      Run      Status    Chassis HT  RAS  CPUs      Memory (GB)    IO Cards  Boot      Boot Boot
 Num      State               OK/In           OK/In     In/OK          OK/In     Chassis   Slots
 ===== ========== ========== ======= === === ========= ============== ========= ======== ============
 p0       Off       OK         1/1   off on    4/4     256/256          0/0      r001i01b  3,5
  * OK/In = OK/Installed

 

References:

  1. HPE Superdome Flex Server – Powering OFF the Server
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Basic Tracing of Jobs Issues in PBS Professional

Step 1: Proceed to the Head Node (Scheduler)

Once you have the Job ID you wish to investigate, go to the Head Node and do. The “-n” is the number of days to search logs at

% tracejob -n 10 jobID

From the tracejob, you will be able to take a peek which node the job landed. Next you can go the node in question and find information from the mom_logs

% vim /var/spool/pbs/mom_logs/thedateyouarelookingat

For example,

% vim /var/spool/pbs/mom_logs/20201211

Using Vim, search for the Job ID

? yourjobID

You should be able to get a good hint of what has happened. In my case is that my nvidia drivers are having issues.

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Licensing error while opening ANSYS Fluent Meshing

The usage of Fluent was smooth. But when I launched the Fluent (Fluent with Meshing)

I’ve got this error. “No license is available at this time”

Taking a look at ANSYS Learning Forum, According to the forum (Licensing error while opening ANSYS Mechanical) “That error message would appear when there is another operation going on that won’t allow the license to be shared , such as meshing or solving, etc.”

To resolve the issue:

  1. Execute the command “/usr/local/ansys_inc/v195/commonfiles/tools/linx64/ansyslm_relutil -userprefs

You should see the dialog box.

You have to go to the bottom of the dialog box “When using Workbench, would you like to”, Use a separate license for each application

Finally, close the application and restart. The issue should go away.

References:

  1. Licensing error while opening ANSYS Mechanical
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Using FIO to measure IO Performance

FIO is a tool for measuring IO performance. You can use FIO to run a user-defined workload and collect the associated performance data.

A good writeup can be found at Fio Basics. For more information, do MAN on fio

Step 1: To Install fio, make sure you activated the epel repository.

# yum install fio

Parameters to be used.

% fio --filename=myfio --size=5GB --direct=1 --rw=randrw --bs=4k --ioengine=libaio --iodepth=256 --runtime=120 --numjobs=4 --time_based --group_reporting --name=iops-test-job --eta-newline=1
  • –filename
    An entire block size or filename can be specified. For example if you are testing block size filename=/dev/sda:/dev/sdb
  • –size
    Indicate the size of the test file generated.  If you are testing the block size and did not specify the size, the entire block will be used.
  • –direct=1
    This means that the page cache is bypassed. No memory is used.
  • –rw
    Check whether IO is access sequentially or randonly. There are a few options.
    read – Sequential reading
    write – Sequential Write
    randread – random reading
    randwrite – random writing
    readwrite , rw – Mixed, sequential workload
    randrw – Mixed Random Workload
  • –bs
    Block Size. By default 4kB is used.
  • –ioengine=libiao
    libaio  enables asynchronous access from the application level. The option would requires –direct=1
  • –iodepth
    Refers to how many requests.
  • –numjobs
    Specifies the number of processes that start the jobs in parallel
  • –runtime
    Terminate processing after the specified period of time
  • –name
    Name of the job
  • –time-based
    fio will run for the duration of the runtime specified
  • –group_reporting
    Display statistics for groups of jobs as a whole instead of for each individual job. This is especially true if
    numjobs is used;