Service:storage

Storage on OACISS systems

OACISS has three separate NAS storage drives, for bulk user data, programs and scratch.

In addition, certain systems may have additional local disks, most often for storage of images related to container infrastructure like Docker.

Main storage: /home/users

Most systems access NAS on Mnemosyne. This is the primary storage engine utilizing 14x12TB Seagate Exos disks in RAID-6. It has 135TB of disk available in a single large volume. Vital statistics:

It is able to maintain up to ~700MBps of write and theoretically up to ~3GBps of read; In the short term, performance may be higher due to caching by nfsd in RAM.

Package tree: /packages

Package trees for RH7, RH8 and ppc64le are stored on two 4TB SAS-12G SSDs in RAID-1.

As packages are subject to almost exclusively read access, they are mounted synchronously.

The SSDs provide 1.2GBps sequential speed.

High performance scratch

Mnemosyne hosts a high-performance 16TB scratch volume made from four 4TB Sabrent Rocket M.2 NVME SSDs configured in RAID-0. This volume is available on the 10Gbit network and on the 100Gbit InfiniBand network.

It is located at /storage/warpspeed.

Sustained sequential read/write is 1.1GBps over the 10G storage network. Sustained R/W over the Infiniband network has currently reached up to approximately 3.5GBps in the relatively short (~20seconds) term, before thermal limiting reduces throughput to 2GBps.

Upstairs storage

Cerberus, Chymera, and the nuc + jetson cluster have access to a smaller 22TB NAS, accessed over 1Gbit ethernet, located on Cerberus.

This storage, and package tree, is entirely separate from main storage.