There are 2 main categories of storage space that are available for purchase on the JHPCE cluster that are listed on the chart below.
1) The blue and green lines represent “pay-as-you-go” space. These spaces include home directory space, legacy storage space, and a couple of “leased” spaces. For these spaces, one is only charged for the actual space that used, and only for the time that data is stored there, at the rate shown in the chart. As a specific example, if one were to use 10 TB of /dcl01/leased space for a year, the cost would be $500/year.
2) The yellow lines on the chart represent “project spaces” that one has to buy into. These are the large storage arrays that we build (historically every 18 months or so) and are funded by various labs that purchase allocations on the storage array. In mid-2018 we stood up our most recent “project space” (/dcl02), so we do not have any additional “project space” available currently. For these “project spaces”, one purchases a set allocation for an initial buy-in fee, and then pays an annual storage management fee. For /dcl02, the buy-in cost was $43/TB. So, as a specific example, if one had purchased a 10TB allocation of /dcl02, the buy-in cost would have been $430, and there would be a $300/year for the storage management fee.
The “pay-as-you-go” spaces are more expensive than the “project spaces” because 1) they are smaller, more-expensive-per-TB devices, 2) the cost of the physical storage array is rolled into the annual fee instead of being charged as an up-front buy-in cost, and 3) they require more time and effort to maintain.
There are also 2 types of scratch storage space on the cluster. The first type of scratch space is the SGE scratch space. The SGE scheduler will create a unique $TMPDIR directory for every job/task that is run on the cluster. This directory is created when the job starts on a compute node, and is removed when the job completes. The $TMPDIR space will be created on the local compute node’s internal disk drives, so the amount of scratch scratch space will vary from node to node, but will be between 500GB and 4TB. The SGE scratch space will typically be faster than other storage space, so this space is useful for intermediary files which do not need to be stored long term, or for jobs which will be performing multiple reads/writes of the same files.
The second type of scratch space is the Personal Scratch space. The Personal Scratch space is a network-based (NFS) filesystem with a backend NVME based storage array. The Personal Scratch space is going to be faster than most other storage on the cluster. The Personal Scratch space is intended to be used for short-term storage of large files, so users are limited to 1TB of space, and files older than 30 days will be purged from the Personal Scratch space. The Personal Scratch space can be accessed via the $MYSCRATCH environment variable from the compute and transfer nodes of the cluster.
Lastly, off-site backup space is available. The /users directory is currently backed up, and other directories can be backed up upon request, and for a modest fee.
Please email bitsupport@lists.jhu.edu if you would like to discuss purchasing storage on the JHPCE cluster.
Current Offerings
Type | Location | Env Var | Capacity | Quota | Lifetime | FY21Q3 Rate | Charge Basis | Notes |
home ZFS | /users/<userid> | $HOME | 34TB | 100GB | long | $345/TByr | used TB | |
temp scratch | /scratch/temp/<JQT> | $TMPDIR | 500GB-4TB | None | transient | free | – | [1][2] |
personal scratch | /fastscratch/myscratch/<userid> | $MYSCRATCH | 22TB | 1TB | 30 days | free | – | [1][3] |
leased Lustre | /dcl02/leased | – | 200TB | as agreed | intermediate | $50/TByr | used TB | |
project ZFS | /dcs04, /dcs05 | – | 5,000TB | as purchased | long | $20/TByr + buyin | purchased TB | [4] |
backup ZFS | varies | – | 2,675TB | – | permanent | $11/TByr | purchased TB | [5] |
Notes: | ||||||||
[All] Rates fluctuate slightly from quarter to quarter based on actual JHPCE expenses and capacities. | ||||||||
[1] Scratch space is only visible on compute and transfer nodes. Scratch is not visible on the login node. <JQT> = ‘job’.’queue’.’task’ | ||||||||
[2] Scratch space varies from node to node base on local disk space. | ||||||||
[3] Currently there is a 1TB quota on files in /fastscratch/myscratch, and a 30 day file retention limit. | ||||||||
[4] The buyin cost for DCS04 is $42/TB. These is very limited capacity still available for sale. | ||||||||
[5] Backups are done of the /users filesystem. Other filesystems may be backed up upon arrangement with PI. |
Previous/Legacy Offerings
The storage spaces listed below are currently in use, but are no longer available for purchase.
Type | Location | Env Var | Capacity | Quota | Lifetime | FY2019Q2 Rate | Charge Basis | Notes |
leased Lustre | /dcl01/leased | – | 200TB | as agreed | intermediate | $50/TByr | used TB | |
leased ZFS | /legacy | – | 100TB | from legacy | short | < $1350/TByr | used TB | [1] |
leased ZFS | /starter/starter-02 | – | 10TB | 10TB | short | $1,041/TByr | used TB | [1] |
project Lustre | /dcl01 | – | 3,400TB | as purchased | long | $26-$29/TByr + buyin | purchased TB | |
project Lustre | /dcl02 | – | 2,463TB | as purchased | long | $22/TB-yr + buyin | purchased TB | |
project ZFS | /dcs01 | – | 688TB | as purchased | long | $20/TByr + buyin | purchased TB | |
Notes: | ||||||||
[1] Users with space in /legacy and /starter may want to consider moving to /dcl01/leased, as it is significantly less expensive. |