| Measurement |
Description |
Measurement Unit |
Interpretation |
| IOPS |
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. |
| TransRate |
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_Hit |
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_Hit |
Indicates the percentage of data written to this logical volume. |
Percent |
|
| C2D_Transfer |
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. |
| BackTrans |
Indicates the rate at which data is transferred by this logical volume to the cache. |
Number/Sec |
|