When you create a file system with the Intelligent-Tiering storage class, you have the option to also provision an SSD read cache that provides SSD latencies for reads of frequently accessed data, up to 3 IOPS per GiB. The SSD read cache has three sizing modes: Automatic, Custom, and None. After your file system is created, you can modify your SSD read cache's sizing mode at any time.
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Considerations when updating SSD read cache sizing mode
Here are a few important considerations when modifying your SSD read cache:
Any time you modify the SSD read cache, all of its contents will be erased. This means that you may see a decrease in performance levels until the SSD read cache is populated again.
You can both increase and decrease the size of the SSD read cache. However, you can only do this once every six hours. There is no time restriction when adding or removing the SSD read cache from your file system.
You must increase or decrease the size of your SSD read cache by a minimum of 10% every time you modify it.
Updating the provisioned SSD read cache
You can update your SSD read cache using the Amazon FSx console, the AWS CLI, or the Amazon FSx API.
Open the Amazon FSx console at https://console.aws.amazon.com/fsx/
. In the left navigation pane, choose File systems. In the File systems list, choose the FSx for OpenZFS file system that you want to update the SSD read cache for.
On the Summary panel, choose Update next to the file system's SSD read cache configuration value.
The Update SSD read cache panel appears.
Select the new sizing mode that you would like for your SSD read cache, as follows:
-
Choose Automatic (Proportional to throughput capacity) to have your SSD read cache automatically sized based on your throughput capacity.
Choose Custom (User-provisioned) if you know the approximate size of your dataset and would like to customize your SSD read cache. If you select Custom, you will also need to specify the Desired read cache capacity in GiB.
Choose None if you do not want to use an SSD read cache with your Intelligent-Tiering file system.
-
Choose Update.
To update the SSD read cache for an Intelligent-Tiering file system, use the AWS CLI command update-file-system or the equivalent UpdateFileSystem API action. Set the following parameters:
Set
--file-system-idto the ID of the file system that you are updating.-
To modify your SSD read cache, use the
--open-zfs-configuration ReadCacheConfigurationproperty. This property has two parameters,SizeGiBandSizingMode:SizeGiB ‐ Sets the size of your SSD read cache in GiB when using
USER_PROVISIONEDmode.SizingMode ‐ Sets the sizing mode of your SSD read cache.
Set to
NO_CACHEif you do not want to use an SSD read cache with your Intelligent-Tiering file system.Set to
USER_PROVISIONEDto specify the exact size of your SSD read cache.Set to
PROPORTIONAL_TO_THROUGHPUT_CAPACITYto have your SSD read cache automatically sized based on your throughput capacity.
The following example updates the SSD read cache sizing mode to USER_PROVISIONED and sets the size to 524288 GiB.
aws fsx update-file-system \ --open-zfs-configuration 'ReadCacheConfiguration={SizeGiB=524288,SizingMode=USER_PROVISIONED}'
To monitor the progress of the update, use the describe-file-systems AWS CLI command. Look for the AdministrativeActions section in the output.
For more information, see AdministrativeAction in the Amazon FSx for OpenZFS API Reference.
Monitoring SSD read cache updates
You can monitor the progress of an SSD read cache update by using the Amazon FSx console, the API, or the AWS CLI.
Monitoring updates in the console
You can monitor file system updates in the Updates tab on the File system details page.
For SSD read cache updates, you can view the following information:
- Update type
-
Supported types are SSD read cache sizing mode and SSD read cache size.
- Target value
-
The updated value for the file system's SSD read cache sizing mode or SSD read cache size.
- Status
-
The current status of the update. The possible values are as follows:
Pending – Amazon FSx has received the update request, but has not started processing it.
In progress – Amazon FSx is processing the update request.
Completed – The update finished successfully.
Failed – The update request failed. Choose the question mark (?) to see details on why the request failed.
- Request time
-
The time that Amazon FSx received the update action request.
Monitoring SSD read cache updates with the AWS CLI and API
You can view and monitor file system SSD read cache update requests using the
describe-file-systems AWS CLI command and the
DescribeFileSystems API operation. The AdministrativeActions array
lists the 10 most recent update actions for each administrative action type. When you
update a file system's SSD read cache, a FILE_SYSTEM_UPDATE
AdministrativeActions is generated.
The following example shows an excerpt of the response of a describe-file-systems
CLI command. The file system has a pending administrative action to change the SSD read cache sizing mode to USER_PROVISIONED and
the SSD read cache size to 524288.
"AdministrativeActions": [
{
"AdministrativeActionType": "FILE_SYSTEM_UPDATE",
"RequestTime": 1586797629.095,
"Status": "PENDING",
"TargetFileSystemValues": {
"OpenZFSConfiguration": {
"ReadCacheConfiguration": {
"SizingMode": "USER_PROVISIONED"
"SizeGiB": 524288,
}
}
}
}
]When the new SSD read cache configuration is available to the file system, the
FILE_SYSTEM_UPDATE status changes to COMPLETED. If the SSD read cache update request fails, the status of the
FILE_SYSTEM_UPDATE action changes to FAILED.
