[gmx-users] append does not work for me

[Michael Brunsteiner]

On 4/21/15 10:41 AM, Michael Brunsteiner wrote:
>>
>> Hi,
>> I just tried to continue a simulation, after having extended the total time using
>>
>> gmx convert-tpr -s original-xxx.tpr -o xxx.tpr -until 400000
>> mdrun -nt 4 -deffnm xxx -cpi xxx.cpt
>>
>> xxx.cpt, xxx.log, and xxx.trr are present  in the working directory and are
>> the original output files, i.e., they were NOT modified
>>
>> but instead of appending the new data gmx makes backups of theoriginal files (i.e. renames xxx.* to #xxx.*.1#)>> and writes the data into new files xxx.*>> this happens both with without the -append option to mdrun ...
>> the original files were produced with gmx 5.0.1 and for the extensioni tried to use gmx 5.0.4 ... can this be the problem?>>if so, is there a work around?>> other than using trjcat, which is tedious as here i am working with HUGE files...>
> Did you enable large file support when you compiled GROMACS?
no ... i wasn;'t aware there is such a thing ... some google-ing suggeststhat the limit is as low as 2Gb ... is that still true for gmx 5.0 ? ... and is it truethat a checkpoint file written with an mdrun compiled without large file support 
and for a trr filesize greater than 2Gb cannot be used for a run continuation? 
is there no work around for that ??

>  Or maybe the file size is an OS limit?

the trajectory files are about 20 Gb, which my 64 bit linux sould be able to handle ...
thanks for the hint!michael