Documentations

NAS Performance: NFS vs. SMB vs. SSHFS | Jake’s Blog

Posted on by Paolo Redaelli

NAS Performance: NFS vs. SMB vs. SSHFS | Jake’s Blog

In trusted home networks NFS without encryption is the best choice on Linux for maximum performance. If you want encryption i would recommend SSHFS, it is a much simpler setup (compared to Kerberos), more cpu efficient and often only slightly slower than plaintext NFS. Samba/SMB is also not too far behind, but only really makes sense in a mixed (Windows/Linux) environment.

Little notes

Posted on by Paolo Redaelli

Just a little note to myself, to start salome on a severly hacked and messed up workstation like mine:

paolo@rigel:~/salome_meca/appli_V2019.0.3_universal$ /home/paolo/salome_meca/appli_V2019.0.3_universal/salome 
runSalome running on rigel
Searching for a free port for naming service: 2815 - OK
Searching Naming Service  + found in 0.1 seconds 
Searching /Kernel/Session in Naming Service  ++++libGL error: MESA-LOADER: failed to open radeonsi (search paths /usr/lib/i386-linux-gnu/dri:/usr/lib/x86_64-linux-gnu/dri)
libGL error: failed to load driver: radeonsi
libGL error: MESA-LOADER: failed to open radeonsi (search paths /usr/lib/i386-linux-gnu/dri:/usr/lib/x86_64-linux-gnu/dri)
libGL error: failed to load driver: radeonsi
libGL error: MESA-LOADER: failed to open swrast (search paths /usr/lib/i386-linux-gnu/dri:/usr/lib/x86_64-linux-gnu/dri)
libGL error: failed to load driver: swrast
Warning: this type (Study,objref) already exists, it will be ignored.
Warning: this type (SALOME_MED/MEDCouplingFieldDoubleCorbaInterface,objref) already exists, it will be ignored.
+Traceback (most recent call last):
  File "/home/paolo/salome_meca/V2019.0.3_universal/modules/KERNEL_V9_3_0/bin/salome/orbmodule.py", line 172, in waitNSPID
    os.kill(thePID,0)
ProcessLookupError: [Errno 3] No such process

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/paolo/salome_meca/appli_V2019.0.3_universal/bin/salome/runSalome.py", line 633, in useSalome
    clt = startSalome(args, modules_list, modules_root_dir)
  File "/home/paolo/salome_meca/appli_V2019.0.3_universal/bin/salome/runSalome.py", line 578, in startSalome
    session=clt.waitNSPID("/Kernel/Session",mySessionServ.PID,SALOME.Session)
  File "/home/paolo/salome_meca/V2019.0.3_universal/modules/KERNEL_V9_3_0/bin/salome/orbmodule.py", line 174, in waitNSPID
    raise RuntimeError("Process %d for %s not found" % (thePID,theName))
RuntimeError: Process 460617 for /Kernel/Session not found


--- Error during Salome launch ---

I can’t recall where I found the solution, bit it is as simple as:

alias salome='LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.28 /home/paolo/salome_meca/appli_V2019.0.3_universal/salome'

I found it on https://code-aster.org/forum2/viewtopic.php?id=23552

What Is Faster In C#: A Struct Or A Class? – C# Architects – Medium

Posted on by Paolo Redaelli

What do you think is faster: filling an array with one million structs, or filling an array with one million classes?

Mark Farragher ask himself What Is Faster In C#: A Struct Or A Class? – C# Architects – on Medium. But of course the third version is faster because he’s not comparing apples and oranges!

The first two routines handles the points by reference while in the third by value. Speaking in Eiffel, the first two versions are “normal” classes, the third is an expanded one. It makes a world of difference!

Well, I do acknowledge that many programming languages does not make the difference manifest.

Pages: