Parallel File Systems
Quotas will be in place to monitor and regulate both the total amount of data and the total number of files used by a particular user. The implementation will include both hard quotas and soft quotas. A hard quota will prevent new file writes from succeeding until the user has freed up space below the quota threshold. The soft quota is a lower threshold, set at 90% of the hard threshold and is equal to the user's quota. When the soft quota is hit, it starts a grace period for the user to clear space or files before having all writes blocked. During this grace period, I/O performance will likely be throttled. Once that probationary period is exceeded and the user has not yet reduced usage below their quota, the soft quota becomes a hard quota and new writes will fail.
There are 3 levels of quotas for users, as shown in Table 1 below. Movement of a user from Tier 1 to Tier 2 may be requested from and implemented by the LC Hotline and are permanent. For those needing additional capacity or number of files, they can provide justication for a custom amount to their account coordinator who can then implement the change for up to six months.
The quota limits are displayed in the following table:
LC Quota Tiers
|Quota Tier||Capacity (TB)||# Files||Grace Period (days)|
|3||Quotas set per amount justified||10|
In all cases, the GPFS filesystems exist only on their individual clusters.
NOTE Large systems such as Quartz, Jade, RZTopaz, and Zin have significantly more bandwidth to Lustre.
|CZ File System||Mount||Capacity (PiB)|
|lustre1||/p/lustre1 (/p/czlustre1 on rzslic)||15|
|lustre2||/p/lustre2 (/p/czlustre2 on rzslic)||15|
|lustre3||/p/lustre3 (only on oslic, rzslic, surface, pascal)||4.9|
RZ File System
|SCF File System||Mount||Capacity (PiB)|
|SNSI File System||Mount||Capacity (PiB)|