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Extended instructions for using Maestro at CSC

Please first read the actual CSC Maestro page and then consult the power user and special case instructions below. Further down there are steps to help solving or diagnosing issues and to prepare data for support requests.

Standalone jobs on Puhti


All Maestro jobs must be run on compute nodes via the queuing system. Don't run any Maestro jobs, including the GUI on the login nodes. Maestro jobs on the login node may be terminated without warning.

The recommended way to run Maestro jobs on Puhti is to create the input files on your local computer and instead of running them, write them to disk. The procedure is shown in this video on our main Maestro page.

Once the files have been copied to Puhti, the job is submitted to a compute node(s) by running the script written out by Maestro. It will formulate the task(s) as Slurm batch job(s) and ask resources according to the selected HOST in your schrodinger.hosts file on your Puhti home directory.

Another, more advanced version is to use e.g. the pipeline tool which allows you to bypass some of the Schrödinger jobcontrol machinery, but requires you to write the job script yourself. This may be useful, in case some of your subjobs terminate unexpectedly. In this case, please make note of those JobIds and contact us at

This article explains some implementation details on Puhti and helps setting up efficient simulation workflows.

Maestro schrodinger.hosts file

This file specifies the resources your jobs can get either locally or from the queuing system. To use the recommended procedure you need to edit the local (on your computer) schrodinger.hosts file to include the same HOSTs that you want to use on Puhti. On Windows, this will require admin privileges.

On Puhti, Maestro complains about the location on this file, but ignore it, it's ok. This file must match the version of Maestro you are using (locally and in Puhti). Version match is checked at each module load event. The file is created by a script (echoed on your screen when you give module load maestro) that you need to run if the file does not exist, or if the versions don't match.

As the script requests, select the computing project that will be used for CPU usage and scratch storage. You can find the actual Slurm options on the HOST descriptions in schrodinger.hosts file. If your jobs require something, that's not present in the file, you can edit it.

On Puhti you can take a look at the schrodinger.hosts file with:

more $HOME/schrodinger.hosts

On your local computer this file will be in the Maestro installation directory, e.g. on Windows in C:\Program Files\Schrodinger-version\schrodinger.hosts

After the longish header and the localhost entry , you should see the Puhti HOST entries as something like:

name:        test
queue:       SLURM2.1
qargs:       -p test -t 00:10:00 --mem-per-cpu=2000 --account=project_2042424
processors:  4

For example, this HOST entry, available for Schrödinger jobs as test (from name: test), will use the Slurm partition test (from -p test), allocate a maximum of 10 minutes of time, 2 GB of memory and consume resources from Project_2042424. If you need different resources you can edit this file, e.g. by adding a new entry. The requests must be within the partition limits.

If your schrodinger.hosts file on Puhti does not have the --account=<something> defined delete the file and rerun the script to create it (module load maestro will print out the path to the script, copy/paste it on the command line). You don't need to have the --account= option set in your local schrodinger.hosts file. In your local file, it's enough that the different HOST entries exist (and the gpu-ones have GPU's specified).

Note that the HOST entries and Slurm partitions (or queues) are two different things. The HOST entries define resources using Slurm partitions.

How to speed up simulations?

All other Maestro modules run serial jobs, except Jaguar and Quantum Espresso, which can run "real" parallel jobs. Don't choose a "parallel" HOST for any other job type. Instead of MPI-parallel jobs, Maestro modules typically split the workload into multiple parts, each of which can be run independent of the others. The Maestro help pages have an excellent section on this topic. Please have a look (you'll find it like this: Click the "help" button in the "run settings dialog", then in the first chapter click the link named "Running Distributed Schrödinger Jobs".

Typically, the workload processes a lot of molecules. If you have enough molecules, you can split the full set into smaller sets, and process each of the sets as a separate job. Since this is typical, the Maestro modules have easy-to-use options to define the number of (sub)jobs. However, you must know in advance how many (sub)jobs to launch. In principle, this requires knowing how long one molecule takes, or testing for each different use case.


When you start with a new kind of work. Don't try if you got the syntax right with 1000000 molecules and 1000 subjobs. Try with 50 molecules and 2 subjobs. Learn how long it takes per molecule, confirm your submit syntax is correct, adjust your parameters if needed and then scale up.

If you're using the GUI to set up the job script, specify how many (sub)jobs (processors) you want to use. (You can easily edit this later in the submit script if you change your mind)

The 'default' submit script will work "as is" for small jobs. Just make sure you don't ask for too many (sub)jobs. Each subjob should take longer than, say one hour to complete, for very large jobs rather 24 hours. Running a lot of very short jobs is inefficient in many ways. For large workflows, you'll need to edit it, see below.

Quantum Espresso

Running multinode jobs using the "parallel" HOST works well with Quantum Espresso when appropriate parallelization flags are carefully specified. The default parallelization is over plane waves if no other options are specified. To improve on this, k-points (if more than one) can be partitioned into "pools" using the -npools flag. Also, when running on several hundred cores, the scalability can be further extended by dividing each pool into "task groups" which distributes the workload associated with Fast Fourier Transforms (FFTs) on the Kohn-Sham states. This is done using the -ntg flag. In order to have good load balancing among MPI processes, the number of k-point pools should be an integer divisor of the number of k-points and the number of processors for FFT parallelization should be an integer divisor of the third dimension of the smooth FFT grid (this can be checked from the output file, grep "Smooth grid" *.out). Further parallelization levels are presented in the QE documentation.

The QE parallelization options can be specified in the Job Settings dialog of the QE calculations panel of the Maestro GUI. Running a job using 160 cores on Puhti (4 nodes) could be parallelized for example with -npools 4 -ntg 4 so that each k-point pool is given 40 cores, which are further divided into 4 task groups of 10 cores each.


When running Maestro modules such as Quantum Espresso on multiple nodes, remember to explicitly request the appropriate number of nodes by editing the schrodinger.hosts file with the --nodes=<number of nodes> flag. Requesting full nodes prevents fragmenting of the system and decreases the amount of unnecessary communication between surplus nodes. For large subjobs you may also need to tune the time and memory requested in the schrodinger.hosts file to suit your needs.


A single core job as required by the driver process cannot be run on the large partition on Puhti. To run multinode subjobs you need to modify the submission script generated by the GUI by specifying a separate driver HOST (e.g. -DRIVERHOST interactive -SUBHOST parallel, see also below)

The following figures show the time to solution and scaling of the PSIWAT benchmark (2552 electrons, 4 k-points, Maestro 2021.3, pure MPI). QE scaling

  • Scaling is almost ideal up to 4 nodes when using -npools 4 -ntg 4 .
  • For this system and QE binary the performance does not scale beyond 320 cores.
  • Always confirm the appropriate scaling of your system before running large multinode jobs (minimum 1.5 times speedup when doubling the number of cores).

Additional flags for Maestro modules

Different modules have different options. You can set some of them in the GUI, but you may find more options with the -h flag:

glide -h

, where glide would be the Maestro module you want to run, like qsite, pipeline, bmin, ligprep, etc.

The Maestro help has a nice summary of the different options for different modules: in Maestro help select: "Installation and jobs" -> "Running Distributed Schrödinger Jobs".

Simple HOST selection

For jobs that finish within about two days, and 10 subjobs just use:

-HOST normal_72h:10

or if they all finish within 7 days, use:

-HOST longrun:10

If you have a workflow that will last longer, read on.

Advanced HOST selection

The general aim is to have the "driver process" running on a "HOST" that will be alive for the whole duration of the workflow. Good options are interactive and longrun, if you estimate the complete workflow to take more than 3 days (queuing included). A "driver process" that is not using a lot of CPU is also allowed on a login node, but a subjob is not. Never submit jobs on Puhti login nodes with -HOST localhost. (It's ok if you create your own batch script and use localhost on a compute node, but that's for special cases only and not discussed on this page.)

Set the "driver" or "master" to run on a HOST that allows for long run times (if it's a big calculation). The driver needs to be alive for the whole duration of the workflow (otherwise, your subjob likely ends up fizzled). You can use "interactive" which allows for 7 days for one core. If you need to run multiple workflows at the same time, choose "longrun" for the next drivers. In both cases select some "normal" HOST (i.e. "small" Slurm partition) for the (sub)jobs. Suitable splitting will reduce your queuing time. Asking for the longrun HOST "just in case" is not dangerous, but may lead to unnecessary queuing.

You may be able to set the number of subjobs already in the GUI. Typically, it would set the "number of processors", which in many drivers will be equal to the number of subjobs. Alternatively, you may be able to set also the number of subjobs. This enables you to limit the number of simultaneous jobs with the "processor count" (so that you and others won't run out of licenses) but keep a single subjob at a suitable size. Please, have a look at the help text of your driver, via the Help path described above.

In summary, for a large workflow edit the GUI generated script along the lines: -HOST "normal_72h:10" to -HOST "longrun:1 normal_72h:9" or e.g. -HOST "normal_72h" to -HOST "interactive:1 normal_72h:9". Another alternative is to use explicit flags, -DRIVERHOST interactive -SUBHOST normal_72h.

Note, that you can have only one single core job running in the interactive HOST.

Desmond jobs can have the -HOST gpu flag as set by the GUI, but Windows users need to change the forward slash "/" to backward slash "\" in the binary name.

Authoritative job control instructions from the manual

A more detailed discussion for advanced jobs can be found in Maestro help via (from the GUI or via login in Schrödinger website):

  • "Job Control Guide" -> "Running jobs" -> "Running Jobs from the Command Line" -> "The HOST, DRIVERHOST, and SUBHOST Options"

and a table for driver process conventions from

  • "Installation and Jobs" -> "Running Distributed Schrödinger Jobs"

Set number of subjobs or molecules per subjob


If you don't know how long your full workflow will take, don't ask for more than 10 subjobs and/or NJOBS. More is not always better. If you have very large cases, don't exceed 50 simultaneous (sub)jobs.

As an example, the "run settings dialog" of Glide offers three options:

  • Recommended number of subjobs
  • Exactly (fill in here) subjobs
  • Subjobs with no more than (fill in here) ligands each

Aim for such numbers that an average subjob takes 2-24 hours to run, so that the overhead per subjob remains small, but not too long so that the job parallelizes efficiently i.e. you get your results quickly and each subjob has time to finish (and that the master job has time to finish). At least avoid subjobs that complete faster than 15 minutes. You can check subjob duration afterwards with seff and use this info in your new jobs:

seff JOBID

If time runs out for a subjob, search for "restart" in the Schrödinger Knowledge Base for yor module, and/or look again for the options of your driver with the -h flag. Most jobs are restartable, so you don't lose completed work or used resources.

If you choose too many subjobs, Maestro will get confused on the Slurm messages and sorting out the issue can be difficult. Also, running too many subjobs at a time can lead to the license running out, and waiting in the queue have been in for nothing.

Optimal disk usage

The Schrödinger HOSTs in Puhti have not been configured to use the NMVE local disk, which is available only on some of the compute nodes. Since most jobs don't gain speed advantage of NVME disk, you'll likely queue less, when not asking for it. If your job will require a lot or random I/O, please contact us at on how to request it. The only disk available for the jobs is the same where your input files already are. Hence, it does not make sense to copy the files to a "temporary" location at the start of the job. However, at the moment there doesn't seem to be a way to prevent that in latest versions (2020.1 onwards).

Copying files to and from local computer

There is a detailed tutorial on how to accomplish this. Below, is an efficient alternative in the command line, which works even in Windows power shell:

In Windows, start the Power Shell by searching for it in the bottom left menu. In Linux or Mac, open a terminal. cd to the directory that has the directory of input files recently written out by the GUI (here named glide-dock_1)

scp -r glide-dock_1

will copy the whole directory (note -r) into your Puhti scratch folder. In a terminal in Puhti, run the job, and once it has completed, you can copy it back (give the command on your local computer):

scp -r .

You might be interested in some additional ssh tips, which will release you from typing your password every time.

Running the Maestro GUI on Puhti

This is not recommended. Running the GUI remotely is slow and prone to glitches. Please run the GUI locally, and only submit the jobs (run the script) on Puhti. If this is not possible, and you have to run the GUI on Puhti, use the interactive partition and NoMachine.

module load maestro
sinteractive -i

Availability of licenses

The CSC Maestro license has a fixed amount of tokens that are available for everyone. First, Maestro uses module specific tokens, of which there are many for each module. If they run out, then more jobs (of that same type) can be run with "general tokens", but when they run out, no more jobs of that type (or any new jobs which need a general token) can't be run by anyone. Therefore, this should be avoided. Once a job ends, the tokens are released, and are available for everyone.

You can check the currently available licenses with:

$SCHRODINGER/utilities/licutil -avail
and currently used licenses with:
$SCHRODINGER/utilities/licutil -used

Note, that some Maestro tools or workflows use multiple modules and hence licenses or tokens from multiple modules. Typically, one running instance of a module (a job or a subjob) requires several tokens. For example, Desmond and Glide jobs take 8 tokes each.

CPU time is a different resource and has nothing to do with license tokens. When CPU-time runs out, you or your project manager can apply for more via

Fizzled jobs

Sometimes the jobs are launched but don't finish. The state of the job as reported by jobcontrol, see below, is fizzled. This might be due to a number of reasons but cleaning up and restarting the jobcontrol service might help. When you don't have any Maestro jobs running (in Puhti), give:

$SCHRODINGER/utilities/jserver -cleanall
$SCHRODINGER/utilities/jserver -shutdown

Another reason is too many simultaneous jobs. Please have a look at the error files for suggestions, and if this is the case, ask for less subjobs.

Run a test job to help problem diagnostics

Run one of the test jobs that come with Maestro to narrow down potential issues. On Puhti, in your scratch directory, give:

installation_check -test test

If the test succeeds, the problem is likely in your input. In that case please proceed to the postmortem step below.

Asking for support

Maestro has a tool called postmortem that can be used to create a zip file containing the details of a failed job and the Maestro environment. Please add that to your support request to help us analyse your issue. On Puhti, first use

jobcontrol -list 

to find the right JobId (something like puhti-login1-0-4d34ce08).

Then, check the right flags for postmortem with

$SCHRODINGER/utilities/postmortem -h

and create the postmortem file with

$SCHRODINGER/utilities/postmortem your-puhti-schrodinger-jobid

The file may be large, so instead of sending it as an email attachment, consider using a-flip and just sending the a link instead. Also, see above the recommendation to try with small systems - it will also enable you to use the test HOST and avoid queueing.

Also, please have a look at these instructions to make support requests that minimize us asking for more details in separate emails and thus taking it longer for you to get the issue solved.

Recap for Maestro usage on Puhti

  • Test your workflow with a small sample first
    • Note, that you can have only one job running at a time in the test and interactive partitions.
  • Don't run the Maestro GUI on the login node (use sinteractive -i if you must run the GUI on Puhti)
  • Don't specify too many subjobs - an optimal subjob takes 2-24 hours
  • Don't specify too many subjobs - there are many researchers using the same license
  • Don't run a heavy "driver process" on the login node (if it's heavy, for 10 simultaneous jobs use -HOST "longrun:1 normal_72h:9")
  • Never run anything in parallel on the login node (localhost should not be in your script)
  • Submit all jobs from your /scratch area
  • If your local computer is Windows, edit \ to / in your script
  • Use the same version of Maestro locally and on Puhti

If you have suggestions on how to improve this text, e.g. to give examples of efficient workflows, fork a copy (top right pen icon), edit and propose merge, or send your suggestion to

Last edited Tue Aug 31 2021