LH Cluster Volume Snapshots Test

This test auto-discovers the snapshots on each volume of the target storage cluster and helps administrators to figure out the snapshot that is busy processing I/O requests, detect irregularities in the distribution of I/O load across the snapshots. In addition, using this test, administrators can analyze the space utilization of each snapshot and thus figure out the snapshots that are running out of space.

Target of the test : A LeftHand SAN Cluster

Agent deploying the test : An external agent

Outputs of the test : One set of results for each volume:snapshot combination on the target storage cluster.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

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

SNMPPort

The port at which the monitored target exposes its SNMP MIB; The default value is 161.

SNMPVersion

By default, the eG agent supports SNMP version 1. Accordingly, the default selection in the SNMPVersion list is v1. However, if a different SNMP framework is in use in your environment, say SNMP v2 or v3, then select the corresponding option from this list.

SNMPCommunity

The SNMP community name that the test uses to communicate with the storage node. This parameter is specific to SNMP v1 and v2 only. Therefore, if the SNMPVersion chosen is v3, then this parameter will not appear.

UserName

This parameter appears only when v3 is selected as the SNMPVersion. SNMP version 3 (SNMPv3) is an extensible SNMP Framework which supplements the SNMPv2 Framework, by additionally supporting message security, access control, and remote SNMP configuration capabilities. To extract performance statistics from the MIB using the highly secure SNMP v3 protocol, the eG agent has to be configured with the required access privileges – in other words, the eG agent should connect to the MIB using the credentials of a user with access permissions to be MIB. Therefore, specify the name of such a user against this parameter. 

Context

This parameter appears only when v3 is selected as the SNMPVersion. An SNMP context is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context and an SNMP entity potentially has access to many contexts. A context is identified by the SNMPEngineID value of the entity hosting the management information (also called a contextEngineID) and a context name that identifies the specific context (also called a contextName). If the Username provided is associated with a context name, then the eG agent will be able to poll the MIB and collect metrics only if it is configured with the context name as well. In such cases therefore, specify the context name of the Username in the Context text box.  By default, this parameter is set to none.

AuthPass

Specify the password that corresponds to the above-mentioned Username. This parameter once again appears only if the SNMPVersion selected is v3.

Confirm Password

Confirm the AuthPass by retyping it here.

AuthType

This parameter too appears only if v3 is selected as the SNMPversion. From the Authtype list box, choose the authentication algorithm using which SNMP v3 converts the specified username and password into a 32-bit format to ensure security of SNMP transactions. You can choose between the following options:

  • MD5 – Message Digest Algorithm
  • SHA – Secure Hash Algorithm

EncryptFlag

This flag appears only when v3 is selected as the SNMPversion. By default, the eG agent does not encrypt SNMP requests. Accordingly, this flag is set to No by default. To ensure that SNMP requests sent by the eG agent are encrypted, select the Yes option. 

EncryptType

If the EncryptFlag is set to Yes, then you will have to mention the encryption type by selecting an option from the EncryptType list. SNMP v3 supports the following encryption types:

  • DES – Data Encryption Standard
  • AES – Advanced Encryption Standard

EncryptPassword

Specify the encryption password here.

Confirm Password

Confirm the encryption password by retyping it here.

Timeout

Specify the duration (in seconds) within which the SNMP query executed by this test should time out in this text box. The default is 10 seconds.

Data Over TCP

By default, in an IT environment, all data transmission occurs over UDP. Some environments however, may be specifically configured to offload a fraction of the data traffic – for instance, certain types of data traffic or traffic pertaining to specific components – to other protocols like TCP, so as to prevent UDP overloads. In such environments, you can instruct the eG agent to conduct the SNMP data traffic related to the monitored target over TCP (and not UDP). For this, set this flag to Yes. By default, this flag is set to No.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Total space

Indicates the total size of this snapshot.

GB

 

Provisioned space

Indicates the space provisioned for this snapshot while created.

GB

 

Used space

Indicates the space that was already utilized on this snapshot.

GB

 

Free space

Indicates the space that is available for use in this snapshot.

GB

 

Snapshot space utilization

Indicates the percentage of space that is utilized in this snapshot.

Percent

A high value for this measure indicates that the snapshot is currently running out of space. Administrators can either clear unwanted data on the snapshot or add additional resources.

Allocated space used

Indicates the percentage of space already utilized from this snapshot against the allocated space for this snapshot.

Percent

 

Free space pct

Indicates the percentage of space that is available for use in this volume.

Percent

 

Allocated free space

Indicates the percentage of space that is available for use from this snapshot against the allocated space.

Percent

 

Cluster space used by snapshot

Indicates the percentage of space utilized by this snapshot on the storage cluster.

Percent

 

I/O read rate

Indicates the rate at which read I/O operations were performed on this snapshot during the last measurement period.

Operations/sec

 

I/O write rate

Indicates the rate at which write I/O operations were performed on this snapshot during the last measurement period.

Operations/sec

 

Data read rate

Indicates the rate at which data was read from this snapshot during the last measurement period.

MB/sec

 

Data Write rate

Indicates the rate at which data was written to this snapshot during the last measurement period.

MB/sec

 

Pending read operations

Indicates the rate at which read operations were pending on this snapshot during the last measurement period.

Operations/sec

 

Pending write operations

Indicates the rate at which write operations were pending on this snapshot during the last measurement period.

Operations/sec

 

Read latency

Indicates the time taken to complete read operations on this snapshot.

MilliSecs

 

Write latency

Indicates the time taken to complete write operations on this snapshot.

MilliSecs

 

Read cache hits

Indicates the rate at which cache of this snapshot was read during the last measurement period.

Operations/sec