Measures reported by NexentaVolPerfTest
NexentaStor enables you to aggregate the available disks in the system into logical data volumes, and then to allocate file or block-based storage from the data volume. The data volume provides a storage pooling capability, so that the file systems, or blocks, can expand without being over-provisioned.
If one/more of these data volumes are slow in processing I/O requests, storage I/O performance may deteriorate, thereby adversely impacting the user experience with the storage device. If this is to be avoided, storage administrators should quickly isolate latent volumes and investigate the reasons for the slowness, so that the problem is fixed before end-users notice the slowdown. The NexentaVolPerfTest test helps administrators with this!
This test auto-discovers the volumes in the NexentaStor device and reports how well each volume handles the I/O requests it receives. In the process, the test points administrators to those volumes that are slow in I/O processing.
The measures made by this test are as follows:
| Measurement |
Description |
Measurement Unit |
Interpretation |
| readOperations |
Indicates the rate at which read operations were performed on this volume. |
Reads/sec |
Ideally, the value of this measure should be high. A steady dip in this measure value could indicate a potential reading bottleneck. |
| writeOperations |
Indicates the rate at which write operations were performed on this volume. |
Writes/sec |
Ideally, the value of this measure should be high. A steady dip in this measure value could indicate a potential writing bottleneck. |
| readBandWidth |
Indicates the rate at which data is read from this volume. |
KB/sec |
Comparing the value of these measures across the volumes will clearly indicate which volume is the slowest in I/O processing, and when exactly the slowdown occurred - when reading data? Or when writing data? |
| writeBandWidth |
Indicates the rate at which data is written to this volume. |
KB/sec |
| readLatency |
Indicates the time taken to read the data from this volume. |
Millisecs |
Compare the value of this measure across volumes to know which volume is the slowest when processing read requests. |
| writeLatency |
Indicates the time taken to write the data to this volume. |
Millisecs |
Compare the value of this measure across volumes to know which volume is the slowest when processing write requests. |
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