Disk reservation
Disk reservation is available in beta release on grimoire cluster in Nancy. Grimoire has height nodes with five bookable disks on each. You can now reserve hard disks, in order to store large datasets between your nodes reservations for example.
How it works
When a job of type deploy starts, the disks you reserved are enabled by the RAID card of the node, and the other disks are disabled. Thus, reserved disks can only be accessed by the user who reserved them.
Main commands
One or several disks can be reserved with the following commands. Note that disk reservation only works with a node reservation of type deploy. What's more, by default, reserving a node on grimoire will only grant access to the main disk.
| Reserve nodes with only their main disk | |
|---|---|
| Reserve 2 nodes | oarsub -I -t deploy -l {"cluster='grimoire'"}/host=2 |
| Reserve nodes with all their disks | |
|---|---|
| Reserve 2 nodes with all their disks | oarsub -I -t deploy -l {"type='disk' or type='default' and cluster='grimoire'"}/host=2 |
| Reserve disks and nodes at the same time | |
|---|---|
| Reserve nodes grimoire-1 and grimoire-2 with 1 disk per node | oarsub -I -t deploy -l {"type='default' and host in ('grimoire-1.nancy.grid5000.fr','grimoire-2.nancy.grid5000.fr')"}/host=2+{"type='disk' and host in ('grimoire-1.nancy.grid5000.fr','grimoire-2.nancy.grid5000.fr')"}/host=2/disk=1 |
| Reserve disks and nodes separately | |
|---|---|
| 1 Reserve disks on the long term | |
| Reserve the first two disks on grimoire-1 and grimoire-2 on January 1st, for 7 days | oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and host in ('grimoire-1.nancy.grid5000.fr', 'grimoire-2.nancy.grid5000.fr') and disk in ('1', '2')"}/host=2/disk=2,walltime=168 |
| Reserve two disks by node on grimoire-1 and grimoire-2 on January 1st, for 7 days | oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and host in ('grimoire-1.nancy.grid5000.fr', 'grimoire-2.nancy.grid5000.fr')"}/host=2/disk=2,walltime=168 |
| Reserve two disks by node on 2 nodes on January 1st, for 7 days | oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and cluster='grimoire'"}/host=2/disk=2,walltime=168 |
| Reserve all disks on 2 nodes on January 1st, for 7 days | oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and cluster='grimoire'"}/host=2/disk=ALL,walltime=168 |
| 2 Reserve nodes for an experiment | |
| Reserve nodes grimoire-1 and grimoire-2 for 1 hour | oarsub -I -t deploy -l {"host in ('grimoire-1.nancy.grid5000.fr', 'grimoire-2.nancy.grid5000.fr')"}/host=2 |
Potential issues
Data loss
Your data are not garanteed against data loss. Your data will not be backuped by Grid'5000 and you must be cautious because several events such as a disk failure or a bad command on the node may delete your data.
Security issues
Unfortunately, it is not possible to avoid a malicious user to take control of the RAID card and therefore of the disks. If you have sensitive data and don't know how to protect them, you may contact the technical team to help you. It is also your responsibility to erase the data on the disks you reserved, at the end of your experiment.