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20000925: upgrading to the ldm-mcidas pnga2area decoder (cont.)

>From: Erick Lorenz <address@hidden>
>Organization: UC Davis
>Keywords: 200009220039.e8M0dBb07890 McIDAS-X 7.60 Linux


re: multiple announcements
>I remember those announcements but they didn't sink in that they applied to
>the AREA files. I think I was hoping that since I was getting the latest
>version that all this would be in place.

>>redirect.k ADD ROUTE.SYS \"/var/data/mcidas
>>batch.k CIMSS.BAT
>I had to do a ROUTE INIT first before this worked.

I had assumed tht since you were attempting to use lwtoa3 that you had
already put a copy of a viable ROUTE.SYS into the target directory,
/var/data/mcidas in your case.  The addition of the CIMSS products to
the routing table would then be an extra.  The fact that you did not
have to do a ROUTE INIT tells me one of two things:

o your REDIRECTion to the copy of ROUTE.SYS in the output data directory
  did not exist

o you had a valid REDIRECTion, but no routing table

>Anyway as soon as I did all this, AREA0000 popped up in /var/data/mcidas
>before I could do an ls on that directory so I think everything is fine.

Unfortunately, everything is not fine.  A file named AREA0000 indicates
a problem.  The reason? AREA0000 is an invalid AREA file name.

What you should do is:

<as 'ldm'>
ldmadmin stop

<as 'mcidas'  make sure that the LDM is not running when you do this>
cd workdata
cp ROUTE.SYS /var/data/mcidas
redirect.k ADD ROUTE.SYS \"/var/data/mcidas
batch.k CIMSS.BAT

<as 'ldm'>
ldmadmin start

>Perhaps I should wait to celebrate but I think this a record for the fewest
>number of "HELP!"s on an installation for me.

You are pretty close, but not out of the woods yet.

>I am now going to set up some user accounts that have home directories on
>ATM20, the server, even though the users will be logging in from other
>Linux stations.  I want their home directories to be on the server because
>it is the only host that will be running Linux all the time and besides the
>users will not always be able to get to the same station.
>What I am now wondering is whether it is best to copy the mcidas manager
>directory to each client host so that the user is running mcidas off of
>local binaries or whether it would work to export the mcidas manager from
>ATM20 to all the clients.  

The simplest setup is for each machine to NFS mount the file system
where McIDAS-X is installed.  Then each user's account should include
~mcidas/bin (e.g. /home/mcidas/bin or where ever the McIDAS binaries
are located) in his/her PATH.  Also, each user will need to have McIDAS
environment variables defined for his/her session.  This is done in .cshrc
(C shell users; .profile for Bourne/Korn shell users).  What has to be
defined is described in detail in:

Configuring Unidata McIDAS-X Accounts

>1.   ATM20 (server)            
>               /home/mcidas  (for use on 20 only)
>               /home/users/mcidas-user1
>               /home/users/mcidas-user2
>       ATM51 (client)
>               /usr/local/mcidas (for use by ATM51)
>               /home -> ATM20:/home (nfs mount)
>               /mcidas-user1 -> atm20:/home/users/mcidas-user1
>               /mcidas-user2 -> atm20:/home/users/mcidas-user2
>       ATM52 (client)
>               /usr/local/mcidas (for use by ATM52)
>               /home -> ATM20:/home (nfs mount)
>               /mcidas-user1 -> atm20:/home/users/mcidas-user1
>               /mcidas-user2 -> atm20:/home/users/mcidas-user2
>2.     ATM20 (server)
>               /home/mcidas  (for use by all machines)
>               /mcidas-user1 -> atm20:/home/users/mcidas-user1
>               /mcidas-user2 -> atm20:/home/users/mcidas-user2
>       ATM51 (client)
>               /home -> ATM20:/home (nfs mount) (sees /home/mcidas)
>               /mcidas-user1 -> atm20:/home/users/mcidas-user1
>               /mcidas-user2 -> atm20:/home/users/mcidas-user2
>       ATM52 (client)
>               /home -> ATM20:/home (nfs mount) (sees /home/mcidas)
>               /mcidas-user1 -> atm20:/home/users/mcidas-user1
>               /mcidas-user2 -> atm20:/home/users/mcidas-user2
>My guess is that option 2 might have poorer performance even though users
>are running mcidas with their own CPUs just because the load times are
>dependent on network traffic but it would also be much easier to maintain.
>If (2) is possible is the trade-off worth it?

Performance of NFS on Linux is known to be _not so good_ (but improving with
time), so it might be better to replicate the existence of the ~mcidas
directory strucuture on each machine.

I want to add, however, that if there will be simultaneous McIDAS-X
sessions run from different machines by the same user, then you will
run into problems with the sessions stepping on each other.  From your
listing I think I am seeing that you want to have 4 accounts setup for
McIDAS-X use.  Is this correct?  Are you planning on having more that 4
McIDAS-X sessions active at the same time?  Is your planned setup based
on having a few user accounts that are accessible by a large number of
sessions (again, having multiple McIDAS-X sessions running out of the
same account from multiple machines)?

McIDAS works best (has the least number of potential gotchas) if each
McIDAS-X user runs his/her McIDAS-X session from their own account.
The overhead for doing this is small.  Each user simply needs to have
his/her own mcidas/data subdirectory.  The McIDAS-X binaries are shared
from ~mcidas/bin; the ancillary data files are shared from ~mcidas/data
(ancillary data files are things like map outline files, enhancements,
stretch tables, etc.); and data from /var/data/mcidas (your system setup
from above).  As soon as you try to run simultaneous McIDAS-X sessions
from a single account but on different machines you _will_ run into
problems unless you know exactly what you are doing (and students never
really know what they are doing).

If you give me a better idea of exactly what you are trying to accomplish,
I can help you layout a setup that should work nicely.


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