[GRASS-dev] G_open_cell_old: unable to open raster map

[James McCreight]

Thanks Glynn-

that's exactly the problem. I've never heard of ulimit (I try not to keep so
many files open!). SO glad I know!

Cheers,

James



On Wed, Aug 18, 2010 at 8:11 PM, Glynn Clements <glynn at gclements.plus.com>wrote:

>
> James McCreight wrote:
>
> > I've been forced in to development by this bug (ie i have a only a vague
> > idea of what I'm doing). Help greatly appreciated (need to work on thesis
> > not bugs).
> >
> > Summary:
> >
> > I've generated a location and a mapset, in this mapset I have files named
> > input_file.0001, ... , input_file.nnnn, ... , input_file.3313
> >
> > I'm running  r.hydro.CASC2 (used to be in GRASS), which i've built from
> gipe
> > add-on package.
> > When it gets to approximately nnnn=1016, i get (i'll use the real rast
> and
> > mapset names, in case they are relevant):
> >
> > WARNING: Unable to open raster map
> > <SBB_runoff_lumped_05.1016 at lumped_05_9930>
>
> If it's happening after ~1000 files, I strongly suspect you're hitting
> an OS limit on the number of open file descriptors. It's common to
> have a limit of 1024 open files per process.
>
> Run "ulimit -n" in the shell to determine the soft limit. If this is
> too low, use "ulimit -Hn" to determine the hard limit. The soft limit
> is what the OS actually checks against; you can change the soft limit
> with e.g. "ulimit -n 5000", but you cannot increase it above the hard
> limit, and a non-root user cannot increase the hard limit.
>
> On systems which use PAM, these limits are set in the file
> /etc/security/limits.conf and any files in the directory
> /etc/security/limits.d. This file is read by PAM (specifically, the
> pam_limits.so module) at login, which sets the limits before dropping
> root privilege and switching to the logged in user.
>
> If you have the ability to change that file, a line such as:
>
>        *               hard    nofile             5000
>
> will increase the hard limit to 5000. The limit will take effect for
> subsequent logins (you can run "login" in an xterm to get a shell with
> the new limits if you don't want to quit your current desktop
> session).
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>



-- 
-
******************************************************************************
James McCreight                                  mccreigh @at@ colorado.edu
NASA Earth Science Fellow
PhD Candidate, Water Resources and Environmental Fluid Mechanics
University of Colorado, Boulder
cell: (831) 261-5149
VoIP (to cell): (720) 897-7546
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