This topic describes how to configure and use the StorNext File System (SNFS) Quality of Service (QOS) feature. QOS allows real-time applications to reserve some amount of bandwidth on the storage system. This is known as real-time I/O (RTIO). SNFS gates (that is, throttles) non-real-time applications so their I/O accesses do not interfere with the real-time application.
QOS is a passive implementation in that it does not actively monitor a process’ activity and then schedule the process so that it receives the bandwidth it has requested. It is up to real-time applications to gate their own I/O requests to the desired rate. SNFS QOS provides a “get out of the way” gating for non-real-time I/O requests so they do not hinder the real-time requests.
The remainder of this document explains the client and server configuration settings for QOS; describes the use of tokens and callbacks for gating non-real-time I/O; describes setting real-time I/O on a file; and discusses the performance monitoring tools that are available for diagnosis.
- About Quality of Service
- Real-time I/O
- Non-Realtime I/O Configuration
- Sharing Disk Resources