XIO XEnvs Test

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 XIO XEnvs 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.

Target of the test : An EMC XtremIO Storage array

Agent deploying the test : A remote agent

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

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.


The IP address of the storage device for which this test is to be configured.


The port number at which the storage array listens. The default is NULL.

XtremIO User and XtremIO Password

Provide the credentials of a user who has read only privileges to access the XtremIO storage array in the XtremIO User and XtremIO Password text boxes.

Confirm Password

Confirm the password by retyping it here.


This parameter is applicable only for EMC XtremIO 4.x. By default, None will be chosen from this list. If the target EMC XtremIO storage array is within a XMS Management Server that is auto-discovered, then the IP or host name of that XMS Management Server will be displayed in this list. Select that particular XMS IP to configure this test. If you wish to monitor an EMC XtremIO Storage Array that is either not an integral part of the auto-discovered XMS Management Server or a brand new EMC XtremIO Storage Array, choose the Other option. This will enable you to add a new XMS Managament Server. To know how to add a new XMS Management Server, refer to Adding a new XMS.


The eG agent collects performance metrics by invoking Restful APIs on the target Storage array. Typically, the Restful APIs can be invoked through the HTTP or the HTTPS mode. By default, the eG agent invokes the Restful APIs using the HTTPS mode. This is why, the SSL flag is set to Yes by default. If the target storage array is not SSL-enabled, then the Restful APIs can be accessed through the HTTP mode only. In this case, set the SSL flag to No.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

CPU usage

Indicates the CPU utilization of this X-Env.


A high value for this measure indicates continuous I/O processing by the storage array. If the value of this measure is increasing gradually or is high for a prolonged period, then administrators should check if adequate LUNs/Volumes are available for storage purposes, if the disk drive capacity is adequate or if the storage capacity of the snapshots is adequate. To optimize the CPU utilization, administrators may either increase the storage capacity or clear unwanted storage space for a smoother I/O processing. 

XEnv state

Indicates the current state of this X-Env.


The values reported by this measure and their numeric equivalents are available in the table below:

Measure Value Numeric Value
Active 0
Unknown 1


This measure reports the Measure Values listed in the table above to indicate the state of this X-Env. However, in the graph, this measure is indicated using the Numeric Values listed in the above table.