Disk reservation

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Disk reservation is available for beta testing 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 for a maximum duration of seven days, 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 disk and nodes at the same time

You can reserve one node with its main disk on grimoire cluster

Terminal.png fnancy:
oarsub -I -t deploy -l {"cluster='grimoire'"}/host=1

You can also reserve one node with all its disks

Terminal.png fnancy:
oarsub -I -t deploy -l {"type='disk' or type='default' and disk_reservation_count > 0"}/host=1

disk_reservation_count represents the number of bookable disks on the node. At present only grimoire has bookable disks.

You can reserve nodes grimoire-1 and grimoire-2 with 1 disk per node

Terminal.png fnancy:
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

First : reserve disks

You can decide to reserve some disks for one week, and the corresponding nodes only when you want to carry out an experiment.

You can reserve two disks on grimoire-1 for one week, starting on January 1st

Terminal.png fnancy:
oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and host='grimoire-1.nancy.grid5000.fr'"}/host=1/disk=2,walltime=168

Or you can specify you want the first two disks of grimoire-2

Terminal.png fnancy:
oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and host='grimoire-2.nancy.grid5000.fr' and disk in ('1', '2')"}/host=1/disk=2,walltime=168

You can also reserve all disks of two nodes

Terminal.png fnancy:
oarsub -r "2018-01-01 00:00:00" -t noop -l {"type='disk' and cluster='grimoire'"}/host=2/disk=ALL,walltime=168

Secondly: reserve nodes

You can reserve in the usual way nodes grimoire-1 and grimoire-2 for 3 hours

Terminal.png fnancy:
oarsub -I -t deploy -l {"host in ('grimoire-1.nancy.grid5000.fr', 'grimoire-2.nancy.grid5000.fr')"}/host=2,walltime=3

Data loss

Such as for your home directory, your data on the disks will not be backuped by Grid'5000. You must be cautious : 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 Grid'5000 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.