[Egrants #YKH-515631]: Role of SSDs in our new distributed EDEX setup

Hi Gyorgyi,

Congrats on receiving the Equipment Grants Award!  I'm sorry my response has 
been so delayed, I've 
been out of the office for the long weekend until today.
For the SSD I think it would be best to mount /awips2/data_store/ on it.  It's 
possible you might
also want to partition the disk and mount a portion of /awips2/edex/data/hdf5, 
specifically the 
/radar/ directory (/awips2/edex/edex/data/hdf5/radar). I know the SSD can help 
dramatically reduce
write times, and the data_store directory is a good place to start, and won't 
get too large 
(less than 100GB, it fluctuates throughout the day).  The radar directory will 
end up having a lot
of files, that aren't too large, so it might be worth it as well.  But as you 
mentioned, SSD will
have a life limit for the number of writes.  So there is a balance between 
performance and 
longevity.  I suggest to start with you mount the /awips2/data_store/ on the 
SSD and leave the 
rest on the spinning disk.
/awips2/edex/data/hdf5/ will most likely be where the majority of your disk 
space will be used, 
especially since you want to keep a longer archive (10 days or so if I remember 
correctly).
The ldm queue seems to do best if it's running in memory, so that should be 
helpful. 
Also, we are currently working on some things for model data to help reduce 
latencies and improve
overall EDEX performance, so those may be things we should walk you through if 
we aren't able to 
update our EDEX installer by the time you're setting up your servers.

Again, I apologize in the lengthy delay for response.  I am in the office now 
(well from my house)
and well be responding much quicker.
Let me know if this helps.

--Shay Carter

Software Engineer II
UCAR - Unidata

Ticket Details
===================
Ticket ID: YKH-515631
Department: Support AWIPS
Priority: Normal
Status: Open
===================
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