Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
Hi Mihai,
this is a problem that is not Slurm related. It's rather about: "when does command substitution happen?"
When you write
srun echo Running on host: $(hostname)
$(hostname) is replaced by the output of the hostname-command *before* the line is "submitted" to srun. Which means that srun will happily run it on any (remote) node using the name of the host it is running on.
If you want to avoid this, one possible solution is
srun bash -c 'echo Running on host: $(hostname)'
In this case the command substitution is happening after srun starts the process on a (potentially remote) node.
Regards, Hermann
On 5/28/24 10:54, Mihai Ciubancan via slurm-users wrote:
Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
Dear Hermann, Dear James,
Thank you both for your answers!
I have tried as you suggested using bash -c and it worked. But when I'm trying the following script the "bash -c" trick doesn't work:
#!/bin/bash
#SBATCH --partition=eli #SBATCH --time=24:00:00
#SBATCH --nodelist=mihaigpu2,mihai-x8640 #####SBATCH --gpus=12 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o /data/mihai/stdout_%j #SBATCH -e /data/mihai/stderr_%j
touch test.txt
# Print the hostname of the allocated node srun bash -c 'echo Running on host: $(hostname)'
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 20
srun echo "GPU UUIDs:" srun nvidia-smi --query-gpu=uuid --format=csv,noheader srun bash -c 'echo $CUDA_VISIBLE_DEVICES'
##echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I don't get any output of the command srun bash -c 'echo $CUDA_VISIBLE_DEVICES':
Running on host: mihaigpu2 Running on host: mihai-x8640 Job started at: Tue May 28 13:02:59 EEST 2024 Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b
Job finished at: Tue May 28 13:03:20 EEST 2024
...I'm not interesting on the output of the other 'echo' commands, beside the one with the hostname, that's why I didn't changed.
Best, Mihai
I will try On 2024-05-28 12:23, Hermann Schwärzler via slurm-users wrote:
Hi Mihai,
this is a problem that is not Slurm related. It's rather about: "when does command substitution happen?"
When you write
srun echo Running on host: $(hostname)
$(hostname) is replaced by the output of the hostname-command *before* the line is "submitted" to srun. Which means that srun will happily run it on any (remote) node using the name of the host it is running on.
If you want to avoid this, one possible solution is
srun bash -c 'echo Running on host: $(hostname)'
In this case the command substitution is happening after srun starts the process on a (potentially remote) node.
Regards, Hermann
On 5/28/24 10:54, Mihai Ciubancan via slurm-users wrote:
Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
Dear Mihai,
you are not asking Slurm to provide you with any GPUs:
#####SBATCH --gpus=12
So it doesn't reserve any for you and as a consequence also does not set CUDA_VISIBLE_DEVICES for you.
nvidia-smi works, because it looks like you are not using cgroups at all or at least not "ConstrainDevices=yes" in e.g. cgroup.conf. So it "sees" all the GPUs that are installed in the node it's running on even if none is reserved for you by Slurm.
Regards, Hermann
On 5/28/24 12:07, Mihai Ciubancan wrote:
Dear Hermann, Dear James,
Thank you both for your answers!
I have tried as you suggested using bash -c and it worked. But when I'm trying the following script the "bash -c" trick doesn't work:
#!/bin/bash
#SBATCH --partition=eli #SBATCH --time=24:00:00
#SBATCH --nodelist=mihaigpu2,mihai-x8640 #####SBATCH --gpus=12 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o /data/mihai/stdout_%j #SBATCH -e /data/mihai/stderr_%j
touch test.txt
# Print the hostname of the allocated node srun bash -c 'echo Running on host: $(hostname)'
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 20
srun echo "GPU UUIDs:" srun nvidia-smi --query-gpu=uuid --format=csv,noheader srun bash -c 'echo $CUDA_VISIBLE_DEVICES'
##echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I don't get any output of the command srun bash -c 'echo $CUDA_VISIBLE_DEVICES':
Running on host: mihaigpu2 Running on host: mihai-x8640 Job started at: Tue May 28 13:02:59 EEST 2024 Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b
Job finished at: Tue May 28 13:03:20 EEST 2024
...I'm not interesting on the output of the other 'echo' commands, beside the one with the hostname, that's why I didn't changed.
Best, Mihai
I will try On 2024-05-28 12:23, Hermann Schwärzler via slurm-users wrote:
Hi Mihai,
this is a problem that is not Slurm related. It's rather about: "when does command substitution happen?"
When you write
srun echo Running on host: $(hostname)
$(hostname) is replaced by the output of the hostname-command *before* the line is "submitted" to srun. Which means that srun will happily run it on any (remote) node using the name of the host it is running on.
If you want to avoid this, one possible solution is
srun bash -c 'echo Running on host: $(hostname)'
In this case the command substitution is happening after srun starts the process on a (potentially remote) node.
Regards, Hermann
On 5/28/24 10:54, Mihai Ciubancan via slurm-users wrote:
Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
Dear Hermann,
Thank you for the clarifications and for the quick answer!
Best wishes, Mihai
On 2024-05-28 13:31, Hermann Schwärzler wrote:
Dear Mihai,
you are not asking Slurm to provide you with any GPUs:
#####SBATCH --gpus=12
So it doesn't reserve any for you and as a consequence also does not set CUDA_VISIBLE_DEVICES for you.
nvidia-smi works, because it looks like you are not using cgroups at all or at least not "ConstrainDevices=yes" in e.g. cgroup.conf. So it "sees" all the GPUs that are installed in the node it's running on even if none is reserved for you by Slurm.
Regards, Hermann
On 5/28/24 12:07, Mihai Ciubancan wrote:
Dear Hermann, Dear James,
Thank you both for your answers!
I have tried as you suggested using bash -c and it worked. But when I'm trying the following script the "bash -c" trick doesn't work:
#!/bin/bash
#SBATCH --partition=eli #SBATCH --time=24:00:00
#SBATCH --nodelist=mihaigpu2,mihai-x8640 #####SBATCH --gpus=12 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o /data/mihai/stdout_%j #SBATCH -e /data/mihai/stderr_%j
touch test.txt
# Print the hostname of the allocated node srun bash -c 'echo Running on host: $(hostname)'
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 20
srun echo "GPU UUIDs:" srun nvidia-smi --query-gpu=uuid --format=csv,noheader srun bash -c 'echo $CUDA_VISIBLE_DEVICES'
##echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I don't get any output of the command srun bash -c 'echo $CUDA_VISIBLE_DEVICES':
Running on host: mihaigpu2 Running on host: mihai-x8640 Job started at: Tue May 28 13:02:59 EEST 2024 Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b
Job finished at: Tue May 28 13:03:20 EEST 2024
...I'm not interesting on the output of the other 'echo' commands, beside the one with the hostname, that's why I didn't changed.
Best, Mihai
I will try On 2024-05-28 12:23, Hermann Schwärzler via slurm-users wrote:
Hi Mihai,
this is a problem that is not Slurm related. It's rather about: "when does command substitution happen?"
When you write
srun echo Running on host: $(hostname)
$(hostname) is replaced by the output of the hostname-command *before* the line is "submitted" to srun. Which means that srun will happily run it on any (remote) node using the name of the host it is running on.
If you want to avoid this, one possible solution is
srun bash -c 'echo Running on host: $(hostname)'
In this case the command substitution is happening after srun starts the process on a (potentially remote) node.
Regards, Hermann
On 5/28/24 10:54, Mihai Ciubancan via slurm-users wrote:
Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
Dear Hermann,
Sorry to come back to you, but just to understand...if I run the following script:
#!/bin/bash
#SBATCH --partition=gpu #SBATCH --time=24:00:00
#SBATCH --nodes=2 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o stdout_%j #SBATCH -e stderr_%j
touch test.txt
# Print the hostname of the allocated node echo "Running on host: $(hostname)"
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 60
echo "GPU UUIDs:" nvidia-smi --query-gpu=uuid --format=csv,noheader echo $CUDA_VISIBLE_DEVICES
echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I'm getting the following results:
Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b 0,1,2,3 0,1,2,3 Task completed.
When for the command echo $CUDA_VISIBLE_DEVICES I should get:
0,1,2,3 0,1,2,3,4,5,6,7
This for the some reason that I had problems with hostname?
Thank you, Mihai
On 2024-05-28 13:31, Hermann Schwärzler wrote:
Dear Mihai,
you are not asking Slurm to provide you with any GPUs:
#####SBATCH --gpus=12
So it doesn't reserve any for you and as a consequence also does not set CUDA_VISIBLE_DEVICES for you.
nvidia-smi works, because it looks like you are not using cgroups at all or at least not "ConstrainDevices=yes" in e.g. cgroup.conf. So it "sees" all the GPUs that are installed in the node it's running on even if none is reserved for you by Slurm.
Regards, Hermann
On 5/28/24 12:07, Mihai Ciubancan wrote:
Dear Hermann, Dear James,
Thank you both for your answers!
I have tried as you suggested using bash -c and it worked. But when I'm trying the following script the "bash -c" trick doesn't work:
#!/bin/bash
#SBATCH --partition=eli #SBATCH --time=24:00:00
#SBATCH --nodelist=mihaigpu2,mihai-x8640 #####SBATCH --gpus=12 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o /data/mihai/stdout_%j #SBATCH -e /data/mihai/stderr_%j
touch test.txt
# Print the hostname of the allocated node srun bash -c 'echo Running on host: $(hostname)'
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 20
srun echo "GPU UUIDs:" srun nvidia-smi --query-gpu=uuid --format=csv,noheader srun bash -c 'echo $CUDA_VISIBLE_DEVICES'
##echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I don't get any output of the command srun bash -c 'echo $CUDA_VISIBLE_DEVICES':
Running on host: mihaigpu2 Running on host: mihai-x8640 Job started at: Tue May 28 13:02:59 EEST 2024 Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b
Job finished at: Tue May 28 13:03:20 EEST 2024
...I'm not interesting on the output of the other 'echo' commands, beside the one with the hostname, that's why I didn't changed.
Best, Mihai
I will try On 2024-05-28 12:23, Hermann Schwärzler via slurm-users wrote:
Hi Mihai,
this is a problem that is not Slurm related. It's rather about: "when does command substitution happen?"
When you write
srun echo Running on host: $(hostname)
$(hostname) is replaced by the output of the hostname-command *before* the line is "submitted" to srun. Which means that srun will happily run it on any (remote) node using the name of the host it is running on.
If you want to avoid this, one possible solution is
srun bash -c 'echo Running on host: $(hostname)'
In this case the command substitution is happening after srun starts the process on a (potentially remote) node.
Regards, Hermann
On 5/28/24 10:54, Mihai Ciubancan via slurm-users wrote:
Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
Hi Mihai,
yes, it's the same problem: when you run
srun echo $CUDA_VISIBLE_DEVICES
the value of $CUDA_VISIBLE_DEVICES on the first of the two nodes is substituted into the line *before* srun is called.
srun bash -c 'echo $CUDA_VISIBLE_DEVICES'
is the way to go.
BTW: the job-script I am seeing in your email is not the one that produced the output you are showing. The script does not use srun, so everything will be run only once and only on the first of the two nodes.
Regards, Hermann
On 5/29/24 10:18, Mihai Ciubancan wrote:
Dear Hermann,
Sorry to come back to you, but just to understand...if I run the following script:
#!/bin/bash
#SBATCH --partition=gpu #SBATCH --time=24:00:00
#SBATCH --nodes=2 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o stdout_%j #SBATCH -e stderr_%j
touch test.txt
# Print the hostname of the allocated node echo "Running on host: $(hostname)"
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 60
echo "GPU UUIDs:" nvidia-smi --query-gpu=uuid --format=csv,noheader echo $CUDA_VISIBLE_DEVICES
echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I'm getting the following results:
Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b 0,1,2,3 0,1,2,3 Task completed.
When for the command echo $CUDA_VISIBLE_DEVICES I should get:
0,1,2,3 0,1,2,3,4,5,6,7
This for the some reason that I had problems with hostname?
Thank you, Mihai
On 2024-05-28 13:31, Hermann Schwärzler wrote:
Dear Mihai,
you are not asking Slurm to provide you with any GPUs:
#####SBATCH --gpus=12
So it doesn't reserve any for you and as a consequence also does not set CUDA_VISIBLE_DEVICES for you.
nvidia-smi works, because it looks like you are not using cgroups at all or at least not "ConstrainDevices=yes" in e.g. cgroup.conf. So it "sees" all the GPUs that are installed in the node it's running on even if none is reserved for you by Slurm.
Regards, Hermann
On 5/28/24 12:07, Mihai Ciubancan wrote:
Dear Hermann, Dear James,
Thank you both for your answers!
I have tried as you suggested using bash -c and it worked. But when I'm trying the following script the "bash -c" trick doesn't work:
#!/bin/bash
#SBATCH --partition=eli #SBATCH --time=24:00:00
#SBATCH --nodelist=mihaigpu2,mihai-x8640 #####SBATCH --gpus=12 #SBATCH --exclusive
#SBATCH --job-name="test_job" #SBATCH -o /data/mihai/stdout_%j #SBATCH -e /data/mihai/stderr_%j
touch test.txt
# Print the hostname of the allocated node srun bash -c 'echo Running on host: $(hostname)'
# Print the start time echo "Job started at: $(date)"
# Perform a simple task that takes a few minutes echo "Starting the task..." sleep 20
srun echo "GPU UUIDs:" srun nvidia-smi --query-gpu=uuid --format=csv,noheader srun bash -c 'echo $CUDA_VISIBLE_DEVICES'
##echo "Task completed."
# Print the end time echo "Job finished at: $(date)"
I don't get any output of the command srun bash -c 'echo $CUDA_VISIBLE_DEVICES':
Running on host: mihaigpu2 Running on host: mihai-x8640 Job started at: Tue May 28 13:02:59 EEST 2024 Starting the task... GPU UUIDs: GPU UUIDs: GPU-d4e002a9-409f-79bb-70e1-56c1a473a188 GPU-33b728e2-0396-368b-b9c3-8f828ca145b1 GPU-7d90f7d8-aadf-ba95-2409-8c57bd40d24b GPU-30faa03a-0782-4b6c-dda2-e108159ba953 GPU-37d09257-2582-8080-223a-dd5a646fba43 GPU-c71cbb10-4368-d327-e0e5-56372aa4f10f GPU-a413a75a-15b2-063e-638f-bde063af5c8e GPU-bf12181a-e615-dcd4-5da2-9a518ae1af5d GPU-dfec21c4-e30d-5a36-599d-eef2fd354809 GPU-15a11fe2-33f2-cd65-09f0-9897ba057a0c GPU-2d971e69-8147-8221-a055-e26573950f91 GPU-22ee3c89-fed1-891f-96bb-6bbf27a2cc4b
Job finished at: Tue May 28 13:03:20 EEST 2024
...I'm not interesting on the output of the other 'echo' commands, beside the one with the hostname, that's why I didn't changed.
Best, Mihai
I will try On 2024-05-28 12:23, Hermann Schwärzler via slurm-users wrote:
Hi Mihai,
this is a problem that is not Slurm related. It's rather about: "when does command substitution happen?"
When you write
srun echo Running on host: $(hostname)
$(hostname) is replaced by the output of the hostname-command *before* the line is "submitted" to srun. Which means that srun will happily run it on any (remote) node using the name of the host it is running on.
If you want to avoid this, one possible solution is
srun bash -c 'echo Running on host: $(hostname)'
In this case the command substitution is happening after srun starts the process on a (potentially remote) node.
Regards, Hermann
On 5/28/24 10:54, Mihai Ciubancan via slurm-users wrote:
Hello,
My name is Mihai and a have an issue with a small GPU cluster manage with slurm 22.05.11. I got 2 different output when I'm trying to find out the name of the nodes(one correct and one wrong). The script is:
#!/bin/bash #SBATCH --job-name=test #SBATCH --output=/data/mihai/res.txt #SBATCH --partition=eli #SBATCH --nodes=2 srun echo Running on host: $(hostname) srun hostname srun sleep 15
And the output look like this:
cat res.txt Running on host: mihai-x8640 Running on host: mihai-x8640 mihaigpu2 mihai-x8640
As you can see the output of the command 'srun echo Running on host: $(hostname)' is the same, as the jobs was running twice on the same node, while command 'srun hostname' it's giving me the correct output.
Do you have any idea why the outputs of the 2 commands are different?
Thank you, Mihai
-
Hermann Schwärzler -
Mihai Ciubancan