VSP Gx00 Logical Device Details Test

This test monitors the I/O activity on each logical volume (LDEV) on the storage device, and subsequently helps administrators identify irregularities in load balancing across the volumes.

Target of the test : A Hitachi VSP Gx00 Series storage device

Agent deploying the test : A remote agent

Outputs of the test : One set of results for every logical volume on the Hitachi VSP Gx00 Series device monitored

Configurable parameters for the test
  1. TEST PERIOD - How often should the test be executed
  2. HOST - The host for which the test is to be configured.
  3. PORT - The port at which the device listens. By default, this is set to NULL.
  4. DKC SERIAL NUMBER - Specify the serial number of the target Hitachi VSP Gx00 Series storage device that is to be monitored.

  5. USERID and PASSWORD – To extract metrics from the target storage device, the eG agent should be configured with the credentials of a special user account, which is specifically created for use with the Java export utility. This user account should fulfill the following conditions:

    • Should not possess the ‘write’ permission;
    • Can be of any user type; however, to ensure that the eG agent collects statistics pertaining to all storage partitions, it is recommended that this user is of type storage administrator;

    Specify the credentials of such a user in the USERID and PASSWORD text boxes.

  6. CONFIRM PASSWORD - Confirm the password by retyping it here.
  7. TIMEOUT - Specify the duration (in seconds) beyond which this test should time out in the TIMEOUT text box. The default is 3 seconds.
Measures made by the test:
Measurement Description Measurement Unit Interpretation

I/O operations rate:

Indicates the number of read-write operations performed on this logical volume per second.

IOPS

A high value for this measure is indicative of high I/O activity on the logical volume. Comparing the value of this measure across logical volumes can accurately reveal which volumes are extremely busy, and also enable administrators to easily detect irregularities in load distribution across the volumes.

To uniformly balance load across volumes, you should consider installing additional hardware (e.g., HDDs, disk adapters, cache), or you can use volume migration to migrate high-usage volumes to higher HDD classes and/or to lower-usage parity groups.

Transactions rate:

Indicates the rate at which data transfers occur on this logical volume.

KB/Sec

 

Read IOPS:

Indicates the rate at which data reads are performed on this logical volume.

IOPS

 

Write IOPS:

Indicates the rate at which data is written to this logical volume.

IOPS

 

Read hits:

Indicates the percentage of read requests that were served by this logical volume.

Percent

Ideally, the value of this measure should be high. A low value is a cause for concern, as it indicates that a majority of read requests have failed.

Write hits:

Indicates the percentage of data written to this logical volume.

Percent

 

Cache-to-disk transfers:

Indicates the number of data transfer operations performed from the cache to this logical volume.

Number

A high value for this measure is a sign of good health. A low value or a consistently decreasing value could be a cause for concern, as it indicates that the cache is not writing enough data to the disk; this in turn could overload the cache and hamper its ability to make space for data that is waiting to be written.

Response time:

Indicates the current responsiveness of this logical volume to requests.

Microseconds

Ideally, the value of this measure should be low.

Transfers between disk and cache:

Indicates the rate at which data is transferred by this logical volume to the cache.

Number/Sec