Hybrid File Store Disk Cache Size Guidelines

Updated

Proper sizing of the cache is extremely important so that all configured Hybrid File Store work seamlessly.

If the cache is full, NFS clients can get NO Space errors. When the clients write data to the Hybrid File Store, it is temporarily stored in the disk cache while the backup runs in another thread. After the software backs up the data, it becomes available for pruning. In order to account for this operation, the disk cache must be large enough to store any burst of data that is written faster than it can be backed up. However, it can be difficult to forecast the size of burst data. We recommend that the cache is large enough for at least one day's worth of newly written data. Additional space is beneficial for improving performance when reading data and for overwriting existing data. We also recommend that the cache size be at least 1TB.