From a0fffa265a4e2a2f524fa71043176e86b10d2abd Mon Sep 17 00:00:00 2001 From: mo khan Date: Mon, 8 Feb 2021 10:42:13 -0700 Subject: describe clustering and high availability --- doc/assignment1.md | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/doc/assignment1.md b/doc/assignment1.md index 9b4faf3..353e9f2 100644 --- a/doc/assignment1.md +++ b/doc/assignment1.md @@ -116,7 +116,21 @@ Instructions: Please answer the following questions in complete sentences. Your other operations, the device driver returns status information. 1. Why do clustered systems provide what is considered high-availability service? -1. Describe an operating system’s two modes of operation. + + Clustered systems gather together multiple CPUs to accomplish computational + work. Clustered systems differ from multiprocessor systems in that they are + composed of two or more individual systems joined together. + + Clusted computers share storage and are closely linked via a local area network. + + A high availability service will continue even if one or more systems in the cluster + fail. HA is generally obtained by adding a level of redundancy in the system. + A layer of cluster software runs on the cluster nodes. Each node can monitor one or + more of the others. If the monitored machine fails, the monitoring machine can take + ownership of its storage and restart applications that were running on the failed machine. + The users and clients of the applications see only a brief interruption of service. + +1. Describe an operating system's two modes of operation. 1. Define cache, and explain cache coherency. 1. Describe why direct memory access (DMA) is considered an efficient mechanism for performing I/O. 1. Describe why multicore processing is more efficient than placing each processor on its own chip. -- cgit v1.2.3