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VMAX Performance issues
Hello Experts,
We are trying to understand some of the performance benchmarch results that we have received from SQLIO test on windows 2012.
test scenerio: A windows VM residing on FC pool and it has three drives (C,E,F) all in the same datastore.
C & E drives have same Allocation unit size (4K), C is MBR and E is GPT but as per SQL IO test, the throughput differs. C is slighly slower than E? Can we explain?
F drive has 64K allocation unit and gives best results which is expected.
| Operating System | Windows 2012 R2 | ||||||||||
| Storage profile | Silver | ||||||||||
| File size for SQLIO | 9 GB | ||||||||||
| Disk layout: | |||||||||||
| Drive letter | StartingOffset | Allocation unit size | Partition type | ||||||||
| C: | 1024 KB | 4096 bytes (default) | MBR | ||||||||
| E: | 33 MB | 4096 bytes (default) | GPT | ||||||||
| F: | 33 MB | 64 kilobytes | GPT | ||||||||
| Benchmark results: | |||||||||||
| C: | IOPS | Throughput (MB/sec) | E: | IOPS | Throughput (MB/sec) | F: | IOPS | Throughput (MB/sec) | |||
| Write - 8k random | 20161 | 158 | Write - 8k random | 23905 | 187 | Write - 8k random | 25604 | 200 | |||
| Read - 8k random | 25501 | 199 | Read - 8k random | 27253 | 213 | Read - 8k random | 27293 | 213 | |||
| Write - 64k sequential | 8939 | 559 | Write - 64k sequential | 11905 | 744 | Write - 64k sequential | 14077 | 880 | |||
| Read - 64k sequential | 17317 | 1082 | Read - 64k sequential | 21320 | 1333 | Read - 64k sequential | 21731 | 13 |
regards,
Saurabh
Quincy561
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October 1st, 2015 07:00
Also if the tests are run separately, you should allow time after a write test for the writes to destage before starting another test.
Quincy561
1.3K Posts
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October 1st, 2015 07:00
Is every test run separately? Did you run each one multiple times to see if you always get the same results? Did you pre-write these devices?
Not sure what impact the offset or the partition type has.
Do you have some pre-set expectations for these tests or success criteria?