Use this procedure to determine if you need to add more disks. Note that disks can be over-utilized by making a poor choice for the RAID profile and/or ZFS record size. In this case, it might be possible to reduce existing disk utilization by moving from RAIDZ to mirrored profiles, and/or matching ZFS record sizes to client I/O sizes.
In addition, if the system is configured with no read- or write-optimized flash drives, then all of the I/O operations beyond DRAM are served by disks. For better performance, consider using flash for any workload that includes random reads or synchronous writes.
- Create a worksheet as described in Creating a Worksheet (CLI), select that worksheet, and then enter
hostname:analytics worksheets> select worksheet-000 hostname:analytics worksheet-000> dataset
set name="io.disks[utilization=70]"and then enter
committo add disks with utilization of at least 70% to your worksheet.
hostname:analytics worksheet-000 dataset (uncommitted)> set name="io.disks[utilization=70]" name = io.disks[utilization=70] hostname:analytics worksheet-000 dataset (uncommitted)> commit
done, and then enter
doneagain to exit the context.
hostname:analytics worksheet-000> done hostname:analytics worksheets> done
- Wait at least 30 minutes, and then go to
Note:Thirty minutes is a general guideline. If you have short-duration workloads that are bottlenecked on disk utilization, you may want to consider selecting additional disks at less than 30 minutes.
hostname:> analytics datasets
showto view a list of available datasets.
hostname:analytics datasets> show Datasets: DATASET STATE INCORE ONDISK NAME dataset-000 active 1.27M 15.5M arc.accesses[hit/miss] dataset-001 active 517K 9.21M arc.accesses[hit/miss=metadata hits][L2ARC eligibility] ... dataset-025 active 290K 7.80M io.disks[utilization=70] hostname:analytics datasets>
selectand the dataset with the name
In this example, dataset name
hostname:analytics datasets> select dataset-025
read 1800to read the last 1800 seconds, or 30 minutes, of the dataset.
hostname:analytics dataset-025> read 1800
Examine the data.
You might want to use more disks when at least 50% of existing disks are at least 70% utilized.