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grid [2017/09/27 11:52] popel |
grid [2017/09/27 14:01] popel [Rules] |
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The purpose of these rules is to prevent your jobs to damage the work of your colleagues and to divide the resources among users in a fair way. | The purpose of these rules is to prevent your jobs to damage the work of your colleagues and to divide the resources among users in a fair way. | ||
- | * Read about our [[internal: | + | * Read about our [[internal: |
- | * While your jobs are running (or queued), check your jobs (esp. previously untested setups) and email (including | + | * While your jobs are running (or queued), check your jobs (esp. previously untested setups) and your email (esp. [[internal: |
* You can ssh to any cluster machine, which can be useful e.g. to diagnose what's happening there (using '' | * You can ssh to any cluster machine, which can be useful e.g. to diagnose what's happening there (using '' | ||
* However, **never execute any computing manually** on a cluster machine where you are sshed (i.e. not via '' | * However, **never execute any computing manually** on a cluster machine where you are sshed (i.e. not via '' | ||
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* **Specify the memory and CPU requirements** (if higher than the defaults) and **don' | * **Specify the memory and CPU requirements** (if higher than the defaults) and **don' | ||
* If your job needs more than one CPU (on a single machine) for most of the time, reserve the given number of CPU cores (and SGE slots) with < | * If your job needs more than one CPU (on a single machine) for most of the time, reserve the given number of CPU cores (and SGE slots) with < | ||
- | * < | + | * If you are sure your job needs less than 1GB RAM, then you can skip this. Otherwise, if you need e.g. 8 GiB, you must always use '' |
+ | * Be kind to your colleagues. If you are going to submit jobs that effectively take more than one fifth of our cluster for more than several hours, check if it is free (with '' | ||
+ | | ||
Další doporučení: | Další doporučení: | ||
* Uklízet po sobě lokální data, protože jinak si tam už nikdo nic užitečného nepustí. | * Uklízet po sobě lokální data, protože jinak si tam už nikdo nic užitečného nepustí. | ||
* Vyhnout se hodně divokému paralelnímu přístupu ke sdíleným diskům. NFS server to pak nepěkně zpomalí pro všechny. Distribuujte tedy i data. | * Vyhnout se hodně divokému paralelnímu přístupu ke sdíleným diskům. NFS server to pak nepěkně zpomalí pro všechny. Distribuujte tedy i data. | ||
* Pokud chci spouštět úlohy, které poběží dlouhou dobu (hodiny, dny), nepustím je všechny najednou, aby cluster mohli využívat i ostatní. | * Pokud chci spouštět úlohy, které poběží dlouhou dobu (hodiny, dny), nepustím je všechny najednou, aby cluster mohli využívat i ostatní. | ||
+ | |||
+ | === Memory === | ||
+ | |||
+ | mem_free (or mf): this is a ' | ||
+ | It affects job scheduling. Every machine as an initial value assigned. | ||
+ | When you specify | ||
+ | qsub -l mem_free=4G | ||
+ | SGE finds a machine with mem_free >= 4GB, and subtracts 4GB from it. | ||
+ | |||
+ | This limit is not enforced, so if a job exceeds this limit, the | ||
+ | SGE value of mem_free may not represent the real free memory. | ||
+ | |||
+ | Default value is 1GB. | ||
===== Advanced usage ===== | ===== Advanced usage ===== |