Storage and disk space
All users accouns are given a 1GB home space that is backed up. The home
space is hosted at the ACES site with which a user is affiliated. Home
space directories are visible from all machines in the ACES system.
ACES also provides short term scratch storage capacity for
running computations with large disk space needs. However, long term
backed-up storage is provided by individual groups that participate in
ACES. It is administered according to their own policies.
The short term storage capacity in ACES is visible to all systems within
ACES. Data stored in short term storage is automatically deleted when disk
capacity exceeds 80% on the main "ds-xx" NFS servers and 50% (with a
24-hour grace period) on the compute nodes. When this capacity limit is
reached datasets are deleted by age (oldest first) until disk capacity
falls below the specified (80% or 50%) utilizaion. There are no space
quotas on the short term storage, however, each user account is limited to
one million files on each storage device (e.g. /net/ds-01/scratch-0). This
file count limit is to prevent performance problems in the Linux ext3 file
system format that occur when managing file systems that contain very
large numbers of files.
The scratch storage devices available at present are named:
Additionally, there is local scratch storage available on each of the
compute nodes in ACES. This storage is accessed using path names of the
where HOSTNAME is the name of a compute machine
Please do not hog space on the "local disks" on the compute nodes. Most
of the local disks (e.g. /net/aE34-500-011/scratch) are very fast
(many are 15,000 RPM SCSI units) but have small overall capacities. If at
all possible, please use them only while your PBS jobs have reserved those
particular nodes. And, whenever possible, please cleanup your files and
directories on the compute nodes after each run. As with all the scratch
disks, files will be deleted when the disks become too full.
The following storage machines are "owned" by specific sub-groups within
ACES. These groups have purchased RAID NFS servers for their use and they
dictate who can and can't use them. If you (and/or your PIs) would like
to arrange for the addition of a dedicated RAID server for your data sets,
please contact us on the
ACES-support list. The dedicated machines currently are:
|ds-05, ds-06, ds-08
||Purchased by the Atmosphere-Ocean group -- ask Chris Hill in
advance for permission to use these machines.
||Purchased by the Geo group -- ask Simon McClusky in
advance for permission to use.