update lustre striping command (#222)

Author: sekelle

docs/guides/gb25.md

@@ -32,8 +32,9 @@ The system [Daint][ref-cluster-daint] will be expanded to approximately 2350 Gra
 ```bash
 #!/bin/bash
 
-#SBATCH --account=<account>
-#SBATCH --partition=<todo>
+#SBATCH --account=<group>
+#SBATCH --partition=normal
+#SBATCH --reservation=<group>
 
 srun --uenv=prgenv-gnu/24.11:v2 --view=default -n? -N? ....
 ```
@@ -51,7 +52,7 @@ The fix is to update how the squashfs file for the uenv or container used by you
 ```console title="set lustre striping on uenv squashfs file"
 $ uenv image inspect prgenv-gnu/24.11:v2 --format='{sqfs}'
 /capstor/scratch/cscs/bcumming/.uenv-images/images/6068794b820fb4dd91019d020d6d98334a2f9fd23035a5e4a2f72f9dda5f1260/store.squashfs
-$ lfs setstripe --stripe-count -1 --stripe-size 1M $(uenv image inspect prgenv-gnu/24.11:v2 --format='{sqfs}')
+$ lfs migrate --stripe-count 20 --stripe-size 1M $(uenv image inspect prgenv-gnu/24.11:v2 --format='{sqfs}')
 ```
 
 As an additional precaution, we recommend to increase the default wait threshold for `MPI_Init` from 180 seconds to 300.