Data Storage and Transfers
OLCF users have many options for data storage. Each user has multiple user-affiliated storage spaces, and each project has multiple project-affiliated storage spaces where data can be shared for collaboration. Below we give an overview and explain where each storage area is mounted.
Summary of Storage Areas
The storage area to use in any given situation depends upon the activity you wish to carry out. Storage areas are either user-centric or project-centric, and are further divided by the underlying storage type (e.g., Network File System (NFS), High Performance Storage System (HPSS), IBM Spectrum Scale). Each storage type has a different intended use as described below.
Each user has a User Home area on NFS, and a User Archive area on HPSS. For newer users, the User Archive area is not writable and is only a “link farm” to a user’s project areas on HPSS. For legacy users, the directory remains writable until files have been migrated to an appropriate project area. Each project has a Project Home area on NFS, multiple Work areas on Spectrum Scale, and multiple Archive areas on HPSS. The different storage areas are summarized in the list and table below.
- User Home: Long-term data for routine access that is unrelated to a project. It is mounted on compute nodes of Summit as read only. It is mounted as read/write on the Frontier compute nodes, but we strongly recommend that users launch and run jobs from the Orion parallel filesystem due to its larger storage capacity and superior performance.
- User Archive: A “link farm” with symbolic links to a user’s project directories on HPSS. (Previously this was for non-project data on HPSS; such use is now deprecated)
- Project Home: Long-term project data for routine access that’s shared with other project members. It is mounted on compute nodes of Summit as read only. It is mounted as read/write on the Frontier compute nodes, but we strongly recommend that users launch and run jobs from the Orion parallel filesystem due to its larger storage capacity and superior performance.
- Member Work: Short-term user data for fast, batch-job access that is not shared with other project members.
- Project Work: Short-term project data for fast, batch-job access that’s shared with other project members.
- World Work: Short-term project data for fast, batch-job access that’s shared with users outside your project.
- Member Archive: Long-term project data for archival access that is not shared with other project members.
- Project Archive: Long-term project data for archival access that’s shared with other project members.
- World Archive: Long-term project data for archival access that’s shared with users outside your project.
Area | Path | Enclave | Type | Permissions | Quota | Backups | Purged | Retention | On Compute Nodes |
---|---|---|---|---|---|---|---|---|---|
User Home | /ccs/home/[userid] |
M1, M2 | NFS | User set | 50 GB | Yes | No | 90 days | Summit: Read-only, Frontier: Read/Write |
User Archive [1] | /home/[userid] |
M1 | HPSS | User set | 2TB | No | No | 90 days | No |
User Archive [2] | /home/[userid] |
M1 | HPSS | 700 | N/A | N/A | N/A | N/A | No |
Project Home | /ccs/proj/[projid] |
M1, M2 | NFS | 770 | 50 GB | Yes | No | 90 days | Summit: Read-only, Frontier: Read/Write |
Orion Member Work | /lustre/orion/[projid]/scratch/[userid] |
M1,M2 | Lustre HPE ClusterStor | 700 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Orion Project Work | /lustre/orion/[projid]/proj-shared |
M1,M2 | Lustre HPE ClusterStor | 770 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Orion World Work | /lustre/orion/[projid]/world-shared |
M1,M2 | Lustre HPE ClusterStor | 775 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Alpine Member Work | /gpfs/alpine/[projid]/scratch/[userid] |
M1, M2 | Spectrum Scale. | 700 [3] | 50 TB | No | 90 days | N/A [4] | Read/Write |
Alpine Project Work | /gpfs/alpine/[projid]/proj-shared |
M1, M2 | Spectrum Scale | 770 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Alpine World Work | /gpfs/alpine/[projid]/world-shared |
M1 | Spectrum Scale | 775 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Member Archive | /hpss/prod/[projid]/users/$USER |
M1 | HPSS | 700 | 100 TB | No | No | 90 days | No |
Project Archive | /hpss/prod/[projid]/proj-shared |
M1 | HPSS | 770 | 100 TB | No | No | 90 days | No |
World Archive | /hpss/prod/[projid]/world-shared |
M1 | HPSS | 775 | 100 TB | No | No | 90 days | No |
Moderate Enhanced User Home | /gpfs/arx/[projid]/home/[userid] |
ME | Spectrum Scale | 700 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Moderate Enhanced Member Work | /gpfs/arx/[projid]/scratch/[userid] |
ME | Spectrum Scale | 700 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Moderate Enhanced Project Work | /gpfs/arx/[projid]/proj-shared/[userid] |
ME | Spectrum Scale. | 770 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Open User Home | /ccsopen/home/[userid] |
O | NFS | User set | 50 GB | Yes | No | 90 days | Read-only |
Open Project Home | /ccsopen/proj/[projid] |
O | NFS | 770 | 50 GB | Yes | No | 90 days | Read-only |
Open Member Work | /gpfs/wolf/[projid]/scratch/[userid] |
O | Spectrum Scale | 700 [3] | 50 TB | No | 90 days | N/A [4] | Read/Write |
Open Project Work | /gpfs/wolf/[projid]/proj-shared |
O | Spectrum Scale | 770 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Open World Work | /gpfs/wolf/[projid]/world-shared |
O | Spectrum Scale | 775 | 50 TB | No | 90 days | N/A [4] | Read/Write |
Important
Files within “Work” directories (i.e., Member Work, Project Work, World Work) are not backed up and are purged on a regular basis according to the timeframes listed above.
Note
Moderate Enhanced projects do not have access to HPSS.
Tip
If your home directory reaches its quota, your batch jobs might fail with the error cat: write error: Disk quota exceeded
. This error may not be intuitive, especially if your job exclusively uses work areas that are well under quota. The error is actually related to your home directory quota. Sometimes, batch systems write temporary files to the home directory (for example, on Summit LSF writes temporary data in ~/.lsbatch
), so if the home directory is over quota and that file creation fails, the job will fail with the quota error.
You can check your home directory quota with the quota
command. If it is over quota, you need to bring usage under the quota and then your jobs should run without encountering the Disk quota exceeded
error.
Footnotes
[1] | This entry is for legacy User Archive directories which contained user data on January 14, 2020. |
[2] | User Archive directories that were created (or had no user data) after January 14, 2020. Settings other than permissions are not applicable because directories are root-owned and contain no user files. |
[3] | (1, 2) Permissions on Member Work directories can be controlled to an extent by project members. By default, only the project member has any accesses, but accesses can be granted to other project members by setting group permissions accordingly on the Member Work directory. The parent directory of the Member Work directory prevents accesses by “UNIX-others” and cannot be changed. |
[4] | (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) Retention is not applicable as files will follow purge cycle. |
On Summit, Andes, and the DTNs, additional paths to the various project-centric work areas are available via the following symbolic links and/or environment variables:
- Member Work Directory:
/gpfs/alpine/scratch/[userid]/[projid]
or$MEMBERWORK/[projid]
- Project Work Directory:
/gpfs/alpine/proj-shared/[projid]
or$PROJWORK/[projid]
- World Work Directory:
/gpfs/alpine/world-shared/[projid]
or$WORLDWORK/[projid]
On Frontier these paths point to Orion:
- Member Work Orion Directory:
/lustre/orion/scratch/[userid]/[projid]
or$MEMBERWORK/[projid]
- Project Work Orion Directory:
/lustre/orion/proj-shared/[projid]
or$PROJWORK/[projid]
- World Work Orion Directory:
/lustre/orion/world-shared/[projid]
or$WORLDWORK/[projid]
Notes on User-Centric Data Storage
User Home Directories (NFS)
The environment variable $HOME
will always point to your current home directory. It is recommended, where possible, that you use this variable to reference your home directory. In cases in which using $HOME
is not feasible, it is recommended that you use /ccs/home/$USER
(or /ccsopen/home/$USER
for home directories in the open enclave).
Users should note that since this is an NFS-mounted filesystem, its performance will not be as high as other filesystems.
User Home Quotas
Quotas are enforced on user home directories. To request an increased quota, contact the OLCF User Assistance Center. To view your current quota and usage, use the quota
command:
$ quota -Qs
Disk quotas for user usrid (uid 12345):
Filesystem blocks quota limit grace files quota limit grace
nccsfiler1a.ccs.ornl.gov:/vol/home
4858M 5000M 5000M 29379 4295m 4295m
Note
Moderate enhanced projects home directores are located in GPFS. There is no enforced quota, but it is recommended that users not exceed 50 TB. These directories are subject to the 90 day purge.
User Home Permissions
The default permissions for user home directories is shown in the Filesystem Summary Table. Users have the ability to change permissions on their home directories, although it is recommended that permissions be set to as restrictive as possible (without interfering with your work).
Note
Moderate enhanced projects have home directory permissions set to 0700
and are automatically reset to that if changed by the user.
User Home Backups
If you accidentally delete files from your home directory, you may be able to retrieve them. Online backups are performed at regular intervals. Hourly backups for the past 24 hours, daily backups for the last 7 days, and once-weekly backups are available. It is possible that the deleted files are available in one of those backups. The backup directories are named hourly.*
, daily.*
, and weekly.*
where *
is the date/time stamp of backup creation. For example, hourly.2020-01-01-0905
is an hourly backup made on January 1st, 2020 at 9:05 AM.
The backups are accessed via the .snapshot
subdirectory. Note that ls
alone (or even ls -a
) will not show the .snapshot
subdirectory exists, though ls .snapshot
will show its contents. The .snapshot
feature is available in any subdirectory of your home directory and will show the online backups available for that subdirectory.
To retrieve a backup, simply copy it into your desired destination with the cp
command.
Note
There are no backups for moderate enhanced project home directories.
User Website Directory
Users interested in sharing files publicly via the World Wide Web can request a user website directory be created for their account. User website directories (~/www
) have a 5GB storage quota and allow access to files at http://users.nccs.gov/~user
(where user
is your userid). If you are interested in having a user website directory created, please contact the User Assistance Center at help@olcf.ornl.gov.
User Archive Directories (HPSS)
Note
Use of User Archive areas for data storage is deprecated as of January 14, 2020. The user archive area for any user account created after that date (or for any user archive directory that is empty of user files after that date) will contain only symlinks to the top-level directories for each of the user’s projects on HPSS. Users with existing data in a User Archive directory are encouraged to move that data to an appropriate project-based directory as soon as possible.
The information below is simply for reference for those users with existing data in User Archive directories.
The High Performance Storage System (HPSS) at the OLCF provides longer-term storage for the large amounts of data created on the OLCF compute systems. The mass storage facility consists of tape and disk storage components, servers, and the HPSS software. After data is uploaded, it persists on disk for some period of time. The length of its life on disk is determined by how full the disk caches become. When data is migrated to tape, it is done so in a first-in, first-out fashion.
User archive areas on HPSS are intended for storage of data not immediately needed in either User Home directories (NFS) or User Work directories (GPFS). User Archive directories should not be used to store project-related data. Rather, Project Archive directories should be used for project data.
User Archive Access
Users are granted HPSS access if they are members of projects with Project Archive areas. Users can transfer data to HPSS from any OLCF system using the HSI or HTAR utilities. For more information on using HSI or HTAR, see the HPSS Data Archival System section.
User Archive Accounting
Each file and directory on HPSS is associated with an HPSS storage allocation. Storage allocations are normally associated with one of the user’s projects; however, legacy usage (from files stored to User Archive areas prior to January 14, 2020) may instead be associated with the user or a ‘legacy’ project. To check storage allocation usage, use the comand showusage -s hpss
from an OLCF resource such as Summit or Andes.
For information on usage and best practices for HPSS, please see the HPSS Data Archival System section.
Notes on Project-Centric Data Storage
Project directories provide members of a project with a common place to store code, data, and other files related to their project.
Project Home Directories (NFS)
Open and Moderate Projects are provided with a Project Home storage area in the NFS-mounted filesystem. This area is intended for storage of data, code, and other files that are of interest to all members of a project. Since Project Home is an NFS-mounted filesystem, its performance will not be as high as other filesystems.
Note
Moderate Enhanced projects are not provided with Project Home spaces, just Project Work spaces.
Project Home Path, Quota, and Permissions
The path, quota, and permissions for Project Home directories are summarized in the Filesystem Summary Table.
Quotas are enforced on Project Home directories. To check a Project Home directory’s usage, run df -h /ccs/proj/[projid]
(where [projid]
is the project ID). Note, however, that permission settings on some subdirectories may prevent you from accessing them, and in that case you will not be able to obtain the correct usage. If this is the case, contact help@olcf.ornl.gov for the usage information.
Project Home directories are root-owned and are associated with the project’s Unix group. Default permissions are set such that only members of the project can access the directory, and project members are not able to change permissions of the top-level directory.
Project Home Backups
If you accidentally delete files from your project home directory, you may be able to retrieve them. Online backups are performed at regular intervals. Hourly backups for the past 24 hours, daily backups for the last 7 days, and once-weekly backups are available. It is possible that the deleted files are available in one of those backups. The backup directories are named hourly.*
, daily.*
, and weekly.*
where *
is the date/time stamp of backup creation. For example, hourly.2020-01-01-0905
is an hourly backup made on January 1st, 2020 at
9:05 AM.
The backups are accessed via the .snapshot
subdirectory. Note that ls
alone (or even ls -a
) will not show the .snapshot
subdirectory exists, though ls .snapshot
will show its contents. The .snapshot
feature is available in any subdirectory of your project home directory and will show the online backups available for that subdirectory.
To retrieve a backup, simply copy it into your desired destination with the cp
command.
Project Work Areas
Three Project Work Areas to Facilitate Collaboration
To facilitate collaboration among researchers, the OLCF provides (3) distinct types of project-centric work storage areas: Member Work directories, Project Work directories, and World Work directories. Each directory should be used for storing files generated by computationally-intensive HPC jobs related to a project.
Note
- Moderate enhanced projects do not have World Work directories and the filesystem is called “arx” rather than “alpine”
- Moderate projects subject to export control do not have World Work directories
- Open projects’ work areas are in the “wolf” filesystem rather than “alpine”
The difference between the three storage areas lies in the accessibility of the data to project members and to researchers outside of the project. Member Work directories are accessible only by an individual project member by default. Project Work directories are accessible by all project members. World Work directories are potentially readable by any user on the system.
Permissions
UNIX Permissions on each project-centric work storage area differ according to the area’s intended collaborative use. Under this setup, the process of sharing data with other researchers amounts to simply ensuring that the data resides in the proper work directory.
- Member Work Directory:
700
- Project Work Directory:
770
- World Work Directory:
775
For example, if you have data that must be restricted only to yourself, keep them in your Member Work directory for that project (and leave the default permissions unchanged). If you have data that you intend to share with researchers within your project, keep them in the project’s Project Work directory. If you have data that you intend to share with researchers outside of a project, keep them in the project’s World Work directory.
Backups
Member Work, Project Work, and World Work directories are not backed up. Project members are responsible for backing up these files, either to Project Archive areas (HPSS) or to an off-site location.
Project Archive Directories
Moderate projects without export control restrictions are also allocated project-specific archival space on the High Performance Storage System (HPSS). The default quota is shown on the table at the top of this page. If a higher quota is needed, contact the User Assistance Center.
Note
There is no HPSS storage for Moderate Enhanced Projects, Moderate Projects subject to export control, or Open projects.
Three Project Archive Areas Facilitae Collaboration on Archival Data
To facilitate collaboration among researchers, the OLCF provides (3) distinct types of project-centric archival storage areas: Member Archive directories, Project Archive directories, and World Archive directories. These directories should be used for storage of data not immediately needed in either the Project Home (NFS) areas or Project Work (Alpine) areas and to serve as a location to store backup copies of project-related files.
As with the three project work areas, the difference between these three areas lies in the accessibility of data to project members and to researchers outside of the project. Member Archive directories are accessible only by an individual project member by default, Project Archive directories are accessible by all project members, and World Archive directories are readable by any user on the system.
Permissions
UNIX Permissions on each project-centric archive storage area differ according to the area’s intended collaborative use. Under this setup, the process of sharing data with other researchers amounts to simply ensuring that the data resides in the proper archive directory.
- Member Archive Directory:
700
- Project Archive Directory:
770
- World Archive Directory:
775
For example, if you have data that must be restricted only to yourself, keep them in your Member Archive directory for that project (and leave the default permissions unchanged). If you have data that you intend to share with researchers within your project, keep them in the project’s Project Archive directory. If you have data that you intend to share with researchers outside of a project, keep them in the project’s World Archive directory.
Project Archive Access
Project Archive directories may only be accessed via utilities called HSI and HTAR. For more information on using HSI or HTAR, see the HPSS Data Archival System section.
Data Policies
Information
Although there are no hard quota limits for project storage, an upper storage limit should be reported in the project request. The available space of a project can be modified upon request.
Purge
To keep the Spectrum Scale file system exceptionally performant, files that have not been accessed (e.g. read) or modified in the project and user areas are purged at the intervals shown in the Filesystem Summary Table above. Please make sure that valuable data is moved off of these systems regularly. See HPSS Data Archival System for information about using the HSI and HTAR utilities to archive data on HPSS.
Special Requests
If you need an exception to the limits listed in the table above, such as a higher quota in your User/Project Home or a purge exemption in a Member/Project/World Work area, contact help@olcf.ornl.gov with a summary of the exception that you need.
Data Retention
By default, the OLCF does not guarantee lifetime data retention on any OLCF resources. Following a user account deactivation or project end, user and project data in non-purged areas will be retained for 90 days. After this timeframe, the OLCF retains the right to delete data. Data in purged areas remains subject to normal purge policies.
Orion Lustre HPE ClusterStor Filesystem
Frontier mounts Orion, a parallel filesystem based on Lustre and HPE ClusterStor, with a 679 PB usable namespace (/lustre/orion/). In addition to Frontier, Orion is available on the OLCF’s data transfer nodes, Andes, and some other smaller resources. It is not available from Summit. Files older than 90 days are purged from Orion.
Orion is a cluster of servers with approximately 500 nodes. Each node plays a role in providing a POSIX namespace for users (/lustre/orion/). A file on Lustre consists of one or more components that may hit one or more servers. Lustre has a distributed lock management process for concurrent access to files or regions within files.
Orion has three performance tiers:
- A flash-based performance tier of 5,400 nonvolatile memory express (NVMe) devices that provides 11.5 petabytes (PB) of capacity at peak read-write speeds of 10 TB/s.
- A hard-disk-based capacity tier that provides 679 PB at peak read speeds of 5.5 TB/s and peak write speeds of 4.6 TB/s.
- A flash-based metadata tier of 480 NVMe devices provides an additional capacity of 10 PB.
Orion Performance Tiers and File Striping Policy
Lustre, in addition to other servers and components, is composed of Objects Storage Targets (OSTs) on which the data for files is stored. A file may be “striped” or divided over multiple OSTs. Striping provides the ability to store files that are larger than the space available on any single OST and allows a larger I/O bandwidth than could be managed by a single OST. Striping is one of the main differences between Frontier’s Orion Lustre and Summit’s Alpine GPFS because GPFS has no concept of striping exposed to the user. For Orion, files are striped between object storage targets (OST) in the three capacity tiers to achieve the best performance. Below, we describe this automatic file striping policy and its motivations.
Orion uses a feature called Data-on-Metadata-Trarget (DoM), where a portion of the file is stored along with the file’s metadata. Currently, directories are configured to store up to the first 256 KB of a file on the metadata tier using DoM. This reduces contention and provides better performance for small file I/O. Orion uses a feature called Progressive File Layout (PFL) to change the striping of a file as it grows. For example, a file smaller than 8 MB will be striped to a single OST, and larger files will be striped across multiple OSTs, taking advantage of more hardware resources. As files grow larger, they are automatically striped between the storage tiers. OLCF is refining the automatic file striping policy to optimize I/O performance for users.
Note
Because of the complexity of file striping between Orion’s performance tiers, users should refrain from attempting to manually control file striping. If you feel that the default file striping on Orion is not meeting your needs, please contact OLCF-help so we can work with you to understand your application’s I/O performance.
I/O Patterns that Benefit from File Striping
Lustre’s file striping will most likely improve performance for applications that read or write to a single (or multiple) large shared files.
Striping will likely have little or no performance benefit for:
- Serial I/O, where a single processor performs all the I/O
- Multiple nodes perform I/O but access files at different times.
- Multiple nodes perform I/O simultaneously to different files that are small (each < 100 MB)
- I/O that uses one file per process
Purge
To keep the Lustre file system exceptionally performant, files that have not been accessed (e.g., read) or modified within 90 days in the project and user areas are purged. Please make sure that valuable data is moved off of these systems regularly. See HPSS Data Archival System for information about using the HSI and HTAR utilities and Globus to archive data on HPSS.
Alpine IBM Spectrum Scale Filesystem
Summit mounts a POSIX-based IBM Spectrum Scale parallel filesystem called Alpine. Alpine’s maximum capacity is 250 PB. It is consisted of 77 IBM Elastic Storage Server (ESS) GL4 nodes running IBM Spectrum Scale 5.x which are called Network Shared Disk (NSD) servers. Each IBM ESS GL4 node, is a scalable storage unit (SSU), constituted by two dual-socket IBM POWER9 storage servers, and a 4X EDR InfiniBand network for up to 100Gbit/sec of networking bandwidth. The maximum performance of the final production system will be about 2.5 TB/s for sequential I/O and 2.2 TB/s for random I/O under FPP mode, which means each process, writes its own file. Metada operations are improved with around to minimum 50,000 file access per sec and aggregated up to 2.6 million accesses of 32KB small files.

Figure 1. An example of the NDS servers on Summit
Alpine Performance under non-ideal workloads
The I/O performance can be lower than the optimal one when you save one single shared file with non-optimal I/O pattern. Moreover, the previous performance results are achieved under an ideal system, the system is dedicated, and a specific number of compute nodes are used. The file system is shared across many users; the I/O performance can vary because other users that perform heavy I/O as also executing large scale jobs and stress the interconnection network. Finally, if the I/O pattern is not aligned, then the I/O performance can be significantly lower than the ideal one. Similar, related to the number of the concurrent users, is applied for the metadata operations, they can be lower than the expected performance.
Tips
For best performance on the IBM Spectrum Scale filesystem, use large page aligned I/O and asynchronous reads and writes. The filesystem blocksize is 16MB, the minimum fragment size is 16K so when a file under 16K is stored, it will still use 16K of the disk. Writing files of 16 MB or larger, will achieve better performance. All files are striped across LUNs which are distributed across all IO servers.
If your application occupies up to two compute nodes and it requires a significant number of I/O operations, you could try to add the following flag in your job script file and investigate if the total execution time is decreased. This flag could cause worse results, it depends on the application.
#BSUB -alloc_flags maximizegpfs
Major difference between Lustre HPE ClusterStor and IBM Spectrum Scale
The file systems have many technical differences, but we will mention only what a user needs to be familiar with:
- On Summit, there is no concept of striping from the user point of view. The GPFS will handle the workload, the file system was tuned during the installation.
- On Frontier, Orion does have striping, but because of the complexity of file striping between Orion’s performance tiers, users should refrain from attempting to manually control file striping. If you feel that the default file striping on Orion is not meeting your needs, please contact OLCF-help so we can work with you to understand your application’s I/O performance.
HPSS Data Archival System
There are two methods of moving data to/from HPSS. The more traditional method is via the command-line utilities hsi
and htar
. These commands are available from most OLCF systems. Recently, we added the capability of using Globus to move data to/from HPSS. HPSS is available via the “OLCF HPSS” Globus endpoint. By connecting to that endpoint and the “OLCF DTN” endpoint, you can transfer files between HPSS and other OLCF filesystems. By connecting to “OLCF HPSS” and some other endpoint, you can transfer files to/from an offsite location to HPSS. More details on various transfer methods are available in the Transferring Data section.
HPSS is optimized for large files. Ideally, we recommend sending files 768GB or larger to HPSS. HPSS will handle small files, but write and read performance will be negatively affected with files smaller than 512 MB. We recommend combining small files prior to tranfer. Alternatively you can use htar
to combine them and create the .tar
file directly on HPSS.
Transferring Data
Globus
Three Globus Endpoints have been established for OLCF resources. These are “OLCF DTN”, “OLCF HPSS”, and “NCCS Open DTN”. The “OLCF DTN” endpoint provides access to User/Project Home areas as well as the Alpine filesystem, the “OLCF HPSS” endpoint provides access to HPSS, and the “NCCS Open DTN” endpoint provides access to the Open User/Project Home areas and the Wolf filesystem. By selecting one of these endpoints and some offsite endpoint, you can use Globus to transfer data to/from that storage area at OLCF. By selecting the “OLCF DTN” and “OLCF HPSS” endpoints, you can transfer data between HPSS and one of our other filesystems.
Globus Warnings:
- Globus transfers do not preserve file permissions. Arriving files will have (rw-r–r–) permissions, meaning arriving files will have user read and write permissions and group and world read permissions. Note that the arriving files will not have any execute permissions, so you will need to use chmod to reset execute permissions before running a Globus-transferred executable.
- Globus will overwrite files at the destination with identically named source files. This is done without warning.
- Globus has restriction of 8 active transfers across all the users. Each user has a limit of 3 active transfers, so it is required to transfer a lot of data on each transfer than less data across many transfers.
- If a folder is constituted with mixed files including thousands of small files (less than 1MB each one), it would be better to tar the small files. Otherwise, if the files are larger, Globus will handle them.
Using Globus to Move Data to Orion
The following example is intended to help users who are making the transition from Summit to Frontier to move their data between Alpine GPFS and Orion Lustre. We strongly recommend using Globus for this transfer as it is the method that is most efficient for users and that causes the least contention on filesystems and data transfer nodes.
Note
Globus does not preserve file permissions and will overwrite destination files with identically named sources files without warning.
Here is a recording of an example transfer from Alpine to Orion using Globus and the OLCF DTN: Using Globus to Move Data to Orion.
Below is a summary of the steps for data transfer given in the recording:
1. Login to globus.org using your globus ID and password. If you do not have a globusID, set one up here: Generate a globusID.
- Once you are logged in, Globus will open the “File Manager” page. Click the left side “Collection” text field in the File Manager and type “OLCF DTN”.
- When prompted, authenticate into the OLCF DTN endpoint using your OLCF username and PIN followed by your RSA passcode.
- Click in the left side “Path” box in the File Manager and enter the path to your data on Alpine. For example, /gpfs/alpine/stf007/proj-shared/my_alpine_data. You should see a list of your files and folders under the left “Path” Box.
- Click on all files or folders that you want to transfer in the list. This will highlight them.
- Click on the right side “Collection” box in the File Manager and type “OLCF DTN”
- Click in the right side “Path” box and enter the path where you want to put your data on Orion, for example, /lustre/orion/stf007/proj-shared/my_orion_data
- Click the left “Start” button.
- Click on “Activity“ in the left blue menu bar to monitor your transfer. Globus will send you an email when the transfer is complete.
General Globus Example
- Visit www.globus.org and login

- Then select the organization that you belong, if you don’t work for ORNL, do not select ORNL. If your organization is not in the list, create a Globus account

- Search for the endpoint OLCF DTN


- Declare path

- Open a second panel to declare the new endpoint called OLCF HPSS and use the appropriate path for HPSS


- Select your file/folder and click start. Then an activity report will appear and you can click on it to see the status. When the transfer is finished or failed, you will receive an email




Using Globus From Your Local Workstation
Globus is most frequently used to facilitate data transfer between two institutional filesystems. However, it can also be used to facilitate data transfer involving an individual workstation or laptop. The following instructions demonstrate creating a local Globus endpoint, and initiating a transfer from it to the OLCF’s Alpine GPFS filesystem.
- Visit https://www.globus.org/globus-connect-personal and Install Globus Connect Personal, it is available for Windows, Mac, and Linux.
- Make note of the endpoint name given during setup. In this example, the endpoint is laptop_gmarkom.
- When the installation has finished, click on the Globus icon and select Web: Transfer Files as below

- Globus will ask you to login. If your institution does not have an organizational login, you may choose to either Sign in with Google or Sign in with ORCiD iD.

- In the main Globus web page, select the two-panel view, then set the source and destination endpoints. (Left/Right order does not matter)

- Next, navigate to the appropriate source and destination paths to select the files you want to transfer. Click the “Start” button to begin the transfer.

- An activity report will appear, and you can click on it to see the status of the transfer.

- Various information about the transfer is shown in the activity report. You will receive an email once the transfer is finished, including if it fails for any reason.

HSI
HSI (Hierarchial Storage Interface) is sued to transfer data to/from OLCF systems and HPSS. When retrieving data from a tar archive larger than 1 TB, we recommend that you pull only the files that you need rather than the full archive. Examples of this will be given in the htar section below. Issuing the command hsi
will start HSI in interactive mode. Alternatively, you can use:
hsi [options] command(s)
…to execute a set of HSI commands and then return. To list you files on the HPSS, you might use:
hsi ls
hsi
commands are similar to ftp
commands. For example, hsi get
and hsi put
are used to retrieve and store individual files, and hsi mget
and hsi mput
can be used to retrieve multiple files. To send a file to HPSS, you might use:
hsi put a.out : /hpss/prod/[projid]/users/[userid]/a.out
To retrieve one, you might use:
hsi get /hpss/prod/[projid]/proj-shared/a.out
Here is a list of commonly used hsi commands.
Command | Function |
---|---|
cd | Change current directory |
get, mget | Copy one or more HPSS-resident files to local files |
cget | Conditional get - get the file only if it doesn’t already exist |
cp | Copy a file within HPSS |
rm mdelete | Remove one or more files from HPSS |
ls | List a directory |
put, mput | Copy one or more local files to HPSS |
cput | Conditional put - copy the file into HPSS unless it is already there |
pwd | Print current directory |
mv | Rename an HPSS file |
mkdir | Create an HPSS directory |
rmdir | Delete an HPSS directory |
Additional HSI Documentation
There is interactive documentation on the hsi
command available by running:
hsi help
Additional documentation can be found on the HPSS Collaboration website.
HTAR
HTAR is another utility to transfer data between OLCF systems and HPSS. The htar
command provides an interface very similar to the traditional tar
command found on UNIX systems. The primary difference is instead of creating a .tar file on the local filesystem, it creates that file directly on HPSS. It is used as a command-line interface. The basic syntax of htar
is:
htar -{c|K|t|x|X} -f tarfile [directories] [files]
As with the standard Unix tar
utility the -c
, -x
, and -t
options, respectively, function to create, extract, and list tar archive files. The -K
option verifies an existing tarfile in HPSS and the -X
option can be used to re-create the index file for an existing archive. For example, to store all files in the directory dir1
to a file named /hpss/prod/[projid]/users/[userid]/allfiles.tar
on HPSS, use the command:
htar -cvf /hpss/prod/[projid]/users/[userid]/allfiles.tar dir1/*
To retrieve these files:
htar -xvf /hpss/prod/[projid]/users/[userid]/allfiles.tar
htar
will overwrite files of the same name in the target directory. When possible, extract only the files you need from large archives. To display the names of the files in the project1.tar
archive file within the HPSS home directory:
htar -vtf /hpss/prod/[projid]/users/[userid]/project1.tar
To extract only one file, executable.out
, from the project1
directory in the Archive file called `` /hpss/prod/[projid]/users/[userid]/project1.tar``:
htar -xm -f project1.tar project1/ executable.out
To extract all files from the project1/src
directory in the archive file called project1.tar
, and use the time of extraction as the modification time, use the following command:
htar -xm -f /hpss/prod/[projid]/users/[userid]/project1.tar project1/src
HTAR Limitations
The htar
utility has several limitations.
Apending data
You cannot add or append files to an existing archive.
File Path Length
File path names within an htar
archive of the form prefix/name are limited to 154 characters for the prefix and 99 characters for the file name. Link names cannot exceed 99 characters.
Size
There are limits to the size and number of files that can be placed in an HTAR archive.
Individual File Size Maximum | 68GB, due to POSIX limit |
Maximum Number of Files per Archive | 1 million |
For example, when attempting to HTAR a directory with one member file larger that 64GB, the following error message will appear:
$ htar -cvf /hpss/prod/[projid]/users/[userid]/hpss_test.tar hpss_test/
INFO: File too large for htar to handle: hpss_test/75GB.dat (75161927680 bytes)
ERROR: 1 oversize member files found - please correct and retry
ERROR: [FATAL] error(s) generating filename list
HTAR: HTAR FAILED
Additional HTAR Documentation
For more information about htar
, execute man htar
.
Command-Line/Terminal Tools
Command-line tools such as scp
and rsync
can be used to transfer data from outside OLCF. In general, when transferring data into or out of OLCF from the command line, it’s best to initiate the transfer from outside OLCF. If moving many small files, it can be beneficial to compress them into a single archive file, then transfer just the one archive file. When using command-line tools, you should use the Data Transfer Nodes rather than systems like Summit or Andes.
scp
- secure copy (remote file copy program)- Sending a file to OLCF
scp yourfile $USER@dtn.ccs.ornl.gov:/path/
- Retrieving a file from OLCF
scp $USER@dtn.ccs.ornl.gov:/path/yourfile .
- Sending a directory to OLCF
scp -r yourdirectory $USER@dtn.ccs.ornl.gov:/path/
rsync
- a fast, versatile, remote (and local) file-copying tool- Sync a directory named
mydir
from your local system to the OLCF
rsync -avz mydir/ $USER@dtn.ccs.ornl.gov:/path/
- where:
a
is for archive modev
is for verbose modez
is for compressed mode
- Sync a directory from the OLCF to a local directory
rsync -avz $USER@dtn.ccs.ornl.gov:/path/dir/ mydir/
- Transfer data and show progress while transferring
rsync -avz --progress mydir/ $USER@dtn.ccs.ornl.gov:/path/
- Include files or directories starting with T and exclude all others
rsync -avz --progress --include 'T*' --exclude '*' mydir/ $USER@dtn.ccs.ornl.gov:/path/
- If the file or directory exists at the target but not on the source, then delete it
rsync -avz --delete $USER@dtn.ccs.ornl.gov:/path/ .
- Transfer only the files that are smaller than 1MB
rsync -avz --max-size='1m' mydir/ $USER@dtn.ccs.ornl.gov:/path/
- If you want to verify the behavior is as intended, execute a dry-run
rsync -avz --dry-run mydir/ $USER@dtn.ccs.ornl.gov:/path/
- Sync a directory named
See the manual pages for more information:
$ man scp
$ man rsync
- Differences:
scp
cannot continue if it is interrupted.rsync
can.rsync
is optimized for performance.- By default,
rsync
checks if the transfer of the data was successful.
Note
Standard file transfer protocol (FTP) and remote copy (RCP) should not be used to transfer files to the NCCS high-performance computing (HPC) systems due to security concerns.
Burst Buffer and Spectral Library
Summit has node-local NVMe devices that can be used as Burst Buffer by jobs, and the Spectral Library can help with some of these use cases.