Filesystem and Disk Space

Filesystem and disk space

	Briareo	BaCiuco	Opteron	Helium
home filesystem	33 Gb (as /home mounted via nfs)	90 Gb (as /home mounted via nfs)	361 Gb (as /home mounted via nfs) 171 Gb (as /old_home)	367 Gb (as /u mounted via nfs)
global scratch filesystem (viewable from all nodes)	136 Gb (as /scratch mounted via gpfs)	68 Gb (as /scratch_nfs mounted via nfs)	933Gb (as /scratch mounted via nfs)	459 Gb (as /master_scratch mounted via nfs)
local scratch filesystem (on each compute node)	9.7 Gb	-	109 Gb (as /local_scratch) 186 Gb (as /old_scratch)	208 Gb (64bit) 54 Gb (32 bit) (as /local_scratch)

Briareo

Home filesystem
Home directories are on /home filesystem (34 GB) on the master/login node and are mounted via NFS by the compute nodes (node01-node16).
Each user will therefore have something like: /home/username.
The disk space on the home directories is assigned through the quota system. To check your disk space limit use the command quota -v
A user's home directory is the place to store files that are routinely used in development and day-to-day work. If the output files from production runs are small, then it is reasonable to store them here.
Please note that at the moment there is NO BACKUP of the home filesystem. It is left to user the task to save important data on safe disks.
Quota is enabled.
Scratch filesystem
This is the real working filesystem of the cluster. /scratch is a GPFS (Global Parallel File System ) of about 140 Gbytes. It is physically formed by 8 disks, one of each computing node but is logicallly seen as a single large filesystem by all the nodes.
This filesystem should be used for production runs. especially if I/O performance significantly affects program performance. It can also be used to store large files temporarily.
The filesystem is NFS exported on the master node to facilitate its usage during batch production. Please note that accordingly to GPFS guide "For performance reasons, Linux NFS code caches information at the client and delays updating some state information, such as file size and modification times. Information reported by an NFS client may therefore differ from the GPFS file system on the NFS server node."

Local scratch filesystem
Each compute node has an additional local scratch space of about 11 GB mounted on /local_scratch. This local scratch filesystem should be used for parallel application with parallel I/O already implemented.
This filesystem is not exported on the master node and therefore is not available during interactive sessions.

BaCiuco

Home filesystem
Home directories are on /home filesystem (90 GB) on the master/login node and are mounted via nfs by the compute nodes (node01-node16). Each user will therefore have something like: /u/<groupname>/<username>. Please note that there is NO BACKUP of the home filesystem. It is left to user the task to save important data on safe disks.
Quota is enabled.

Scratch cluster filesystem
/scratch is the real working filesystem of the cluster (68GB).
This filesystem should be used for production runs. It can also be used to store large files temporarily.
The filesystem is NFS exported to the compute nodes to facilitate its usage during batch production.
Quota is enabled.

Opteron

Home filesystem
Home directories are on /home filesystem (171 GB) on the master/login node and are mounted via NFS by the compute nodes.
Each user will therefore have something like: /home/username.
Please note that at the moment there is NO BACKUP of the home filesystem. It is left to user the task to save important data on safe disks.

Scratch filesystem
/scratch is the real working filesystem of the cluster. It is a NFS (Network File System ) of about 186 Gbytes.

Local scratch filesystem
Each compute node has an additional local scratch space of about 109 GB mounted on /scratch_local. This local scratch filesystem should be used for parallel application with heavy I/O requirements.
This filesystem is not exported on the master node and therefore is not available during interactive sessions.

Helium

Home filesystem
Home directories are on /u filesystem (367 GB) on the master/login node and are mounted via NFS by the compute nodes.
Quota is enabled.

Scratch filesystem
Global scratch directory is monted on /master_scratch, viewable from all nodes, and this is the real working filesystem of the cluster. It is a NFS (Network File System) of about 459 Gbytes.
Quota is enabled.
Local scratch filesystem Each compute node has an additional local scratch disc space of about 208 Gb for 64 bit nodes and 54 Gb for 32 bit nodes mounted as /local_scratch