Re: Linux Disk Performance

Ernst Lobsiger
 

Olivier

I'd try the solution with tmp and received on the external HD first.
If it's at least USB3 and the HD is fast enough it should work. If
you get a lot of missed files this may indicate a HD performance
problem as the TelliCast client is not inclined to wait at all
when he wants to write tmp data. Accomplished tmp files are never
copied under Linux but the move is just a rename (thats why they
have to be on the same file system). If you have HD performance
problems you could still try a real RAM disk (module brd) and move new
files with my proven bash script mvmsg to disk. It's a solution as
proposed by Thomas Scheelen but probably more than that: The
follow up problem that you run into with a RAM disk ist that if
you have missed packets the damaged tmp files will stay on your
RAM disk and not be renamed. They are waiting for retransmissions
of the damaged packets an EUMETSAT configured time of typically
3 Hours. But your chances to get the broken tmp files fixed by
retransmission (as an amateur) are close to 0 because you are not
allowed to use NACKs. So these broken tmp files will fill up
your RAM disk. My mvmsg script also checks for tmp files that
have not changed for some time and decides that those are broken
and must be deleted. This way you can take all data BAS, HVS-1,
HVS-2 over a RAM disk of typically 4GB size. But as I said,
only try this if you run into HD performance problems. Make
sure you only take the data you need. name=* and target default
is only something to begin with ...


Cheers,
Ernst

P.S. You posted while I have been writing this. I post it anyway.

Join MSG-1@groups.io to automatically receive all group messages.