/[MITgcm]/MITgcm_contrib/llc_hires/llc_90/code-async/readme.txt
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revision 1.3 by dimitri, Sun Mar 3 01:17:30 2019 UTC revision 1.4 by dimitri, Sun Mar 3 13:59:35 2019 UTC
# Line 10  information they need directly from "SIZ Line 10  information they need directly from "SIZ
10  for the run only need to be edited in one place (namely, SIZE.h).  for the run only need to be edited in one place (namely, SIZE.h).
11    
12  One tile per rank is recommended, mostly for pickup input performance,  One tile per rank is recommended, mostly for pickup input performance,
13  but it is not strictly necessary.  but it is not strictly necessary.  A minimum of one full node of I/O
14    ranks is required.  The async I/O does allocate whole nodes to be
15    either an I/O node, or a compute node.  It is permitted for the last
16    *compute* node to have a "ragged edge", i.e., have fewer MPI processes
17    on it than the other nodes do.  But the I/O nodes are all "full size".
18    
19    The other minimum value the I/O code requires is that there must
20    be at least one core for each field you want to write, e.g., if you
21    are dumping 20 different fields, there must be at least 20 cores
22    allocated to the I/O.  Note that the 20 (or whatever) number is
23    *aggregate* across all the I/O nodes, NOT a "per node" number.
24    
25  Choose dumpFreq and pChkptFreq as usual. We're not set up  Choose dumpFreq and pChkptFreq as usual. We're not set up
26  to do the rolling checkpoints yet. It'll dump u,v,t, and etan now -  to do the rolling checkpoints yet. It'll dump u,v,t, and etan now -
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