[Beowulf] Lmod question

David Mathog mathog at caltech.edu
Fri Jun 19 15:20:26 PDT 2020

On 18 Jun 2020 16:18:53 -0700 (PDT) David Mathog wrote:

> module --config 2>&1 | grep -i cache
> number of cache dirs               0
> Ignore Cache                       no
> Cached loads                       no
> User cache valid time(sec)         86400
> Write cache after (sec)            2

On Fri, 19 Jun 2020 00:50:27 Jörg Saßmannshausen wrote:

> If I recall correctly, there is a parameter for how long the cache is 
> valid.
> So you either set it very low, and the cache will be regenerated very 
> often,
> or very high, so the cache will be generated once and stays then like 
> this.
> Maybe that is something you want to look into?

That is the 86400 number above.  (==24 hours).  The thing is, the same 
version of Lmod on the problem machine (A, CentOS 8) and another (B, 
CentOS 7).  Both have the same value for it.

There is something strange where it is using the spider/cache on one 
machine and not at all on the other.

On A, using the "modules" account after deleting "~/.lmod.d" yesterday
doing "module avail" regenerated the .cache files.  On B there was a 
very old cache file (from 2019).   Doing this on B:

mv ~/.lmod.d/ ~/save.lmod.d
module avail

did not regenerate the directory or files.  There must be somewhere a 
configuration setting which is telling B not to use the cache files at 
all, but on A that is set another way.  Unfortunately, as noted in the 
first post "module --config" is the same on A and B other than some 
version numbers.  Here is A's with
B's differences in parentheses:

Modules based on Lua: Version 8.2.7  2019-11-30 09:41 -06:00
     by Robert McLay mclay at tacc.utexas.edu

Description                        Value
-----------                        -----
Allow TCL modulefiles              yes
Auto swapping                      yes
Case Independent Sorting           no
Colorize Lmod                      yes
Disable Same Name AutoSwap         no
Using dotfiles                     yes
Allow duplicate paths              no
Require Exact Match/no defaults    no
Export the module command          yes
Allow extended default             yes
Use attached TCL over system call  yes
Use italic instead of dim          no
Language used for err/msg/warn     en
Site message file                  <empty>
LD_LIBRARY_PATH at config time     <empty>
LD_PRELOAD at config time          <empty>
LuaFileSystem version              1.6.3  (1.6.2)
Lmod version                       8.2.7
Lua Version                        Lua 5.3 (5.1)
System lua-term                    yes
Active lua-term                    true
MODULERCFILE                       /usr/share/lmod/etc/rc -> <empty>
avail: Include modulepath dir      no
/usr/share/lmod/lmod/init/.modulespath -> <em
MODULEPATH_ROOT                    /usr/share/modulefiles
number of cache dirs               0
OS Name                            CentOS Linux release 8.1.1911 (Core) 
Pager                              /usr/bin/more
Pager Options                      -XqMREF
Path to HashSum                    /usr/bin/sha1sum
Path to Lua                        /usr/bin
Pin Versions in restore            no
Pkg Class name                     Pkg
Lmod prefix                        /usr/share
Site controlled prefix             no
Prepend order                      normal
Redirect to stdout                 no
Supporting Full Settarg Use        no
User shell                         bash
Site Name                          <empty>
Site Pkg location                  standard
Ignore Cache                       no
Cached loads                       no
System Name                        <empty>
SYSHOST (cluster name)             <empty>
TCL Version                        8.6.8 (8.5.3)
User cache valid time(sec)         86400
Write cache after (sec)            2
Threshold (sec)                    1
Tmod find first rule               no
Tmod prepend PATH Rule             no
Tracing                            no
uname -a                           Linux poweredge.cluster 
x86_64 #1 SMP Wed Feb 5 02:00:39 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux 
( 3.10.0-1062.12.1
Admin file                         /usr/share/lmod/etc/admin.list

Changes from Default Configuration

Name                  Default  Value
----                  -------  -----
(LFS_VERSION           1.6.3    1.6.2   (B machine only))
LMOD_FAST_TCL_INTERP  no       yes
LMOD_HAVE_LUA_TERM    no       yes
LMOD_PAGER            less     /usr/bin/more
LMOD_TCLSH            tclsh    /usr/bin/tclsh
MODULEPATH_ROOT                /usr/share/modulefiles
PATH_TO_LUA           lua      /usr/bin

Active RC file(s):

(and the rest is identical.)

The lmodrc.lua files are identical on A and B.

rpm --verify Lmod

is identical on A and B except for the


files where the path differs by having an 8 in one position on A and a 7 
in that spot on B.  Comparing the spider* files from the rpm they only 
differed in contents with reference to the TCL etc. version numbers 
mentioned above.   There is a trace option in Lmod, but it apparently 
does nothing for "module avail".

In short, hard to understand what is going on here!


David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech

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