Measures reported by XIOXEnvsTest

By default, each X-Brick comprises of two storage controller nodes and each storage controller consists of two CPU sockets. An XIOS instance called the X-ENV runs on each CPU socket. There are 6 software modules that are responsible for various functions such as I/O flow, I/O processing etc in the XTREMIO storage array. The first 3 (R,C,D) are data plane modules and the last 3 (P,M,L) are control plane modules. Each of these modules are explained in detail as follows:

P - Platform Module. This module is responsible for monitoring the hardware of the system. Each node runs a P-module.

M - Management Module. This module is responsible for system wide configurations. It communicates with the XMS management server to perform actions such as volume creation, host LUN masking, etc from the GUI and CLI. There is one active M-module running on a single node, and the other nodes run a stand-by M-module for HA purposes.

L - Clustering Module. This clustering module is responsible for managing the cluster membership state, joining the cluster, and typical cluster functions. Each node runs an L-module.

R - Routing Module. This module is the SCSI Command parser and translates all host SCSI commands into internal XtremIO commands/addresses. It is responsible for the 2 FC and 2 iSCSI ports on the node and functions as the ingress/egress point for all I/O of the node. It is also responsible for breaking all I/O into 4K chunks and calculating the data hash values via SHA-1. Each node runs an R-Module.

C - Control Module. This module contains the address to hash mapping table (A2H) which is the first layer of indirection that allows much of the “magic” to happen. Many of the advanced data services such as snapshots, de-duplication, thin provisioning, etc are all handled in this module.

D - Data Module. The data module contains the hash to physical (H2P) SSD address mapping. It is also responsible for doing all of the I/O to the SSDs themselves as well as managing the data protection scheme, called XDP (XtremIO Data Protection).

Each storage controller node is configured specifically to run R and C modules on one CPU socket and the D module is run on the other CPU socket. When communication between the RC and D modules happens evenly, then the I/O processing will be smooth and uniform. If for any reason the XIOS instance aka X-ENV is inactive, the corresponding storage controller node may fail leading to performance degradation of the XTREMIO storage array. Also, if the CPU utilization of the X-Env is not maintained optimally, then the I/O processing may not be uniform. In order to maintain uniform I/O processing, it becomes important to continuously monitor the state and CPU utilization of each X-Env. The XIOXEnvsTest test exactly helps you in this regard. This test auto-discovers the X-Envs of the target storage array and reports the current state and CPU utilization of each X-Env.

Outputs of the test : One set of results for each X-Env of the EMC XtremIO Storage array that is being monitored

The measures made by this test are as follows: