This topic describes how to manage a cache disk in the Cloud Storage Gateway (CSG) console. For example, you can attach a cache disk and increase cache disk capacity.
Prerequisites
An Internet Small Computer System Interface (iSCSI) gateway is created. For more information, see Create an iSCSI gateway.
Background information
Currently, iSCSI volumes support the Cache and Write Through modes. You can select a cache disk for each iSCSI volume that has the Cache mode enabled. The Cache mode allows read and write operations to use local cache disks first. If you need to create an iSCSI volume that has the Cache mode enabled, you must add a cache disk to the iSCSI gateway first.
Methods introduced in this topic apply only to cache disk management of iSCSI gateways deployed in Alibaba Cloud. If you want to add a cache disk for an on-premises iSCSI gateway, you must add a cache disk in the on-premises console. For more information, see Add disks.
Add a cache disk
On the Gateways page, click the ID of the iSCSI gateway. On the page that appears, click .
Specify cache disk specifications by using Cache Calculator or Custom Cache.
NoteCapacity
The capacity of a cache disk for a Basic gateway ranges from 20 GB to 4,096 GB.
The capacity of a cache disk for a Standard gateway ranges from 20 GB to 8,192 GB.
The capacity of a cache disk for an Enhanced or Performance Optimized gateway ranges from 20 GB to 32,768 GB.
Type
Select Ultra Disk, Standard SSD, or ESSD based on your business requirements.
If you add a cache disk to a Subscription gateway, you are redirected to the cache disk purchase page. For more information, see Purchase a cache disk.
Increase cache disk capacity
On the Caches tab, click the cache disk and click the plus (+) icon in the Actions column.
In the Scale Up Cache dialog box, set the new size of the cache disk, and then click OK.
NoteWhen you increase the cache disk capacity, the limit on the new capacity varies with the edition of the gateway.
Basic: The new capacity must be greater than the current capacity and less than or equal to 4,096 GB.
Standard: The new capacity must be greater than the current capacity and less than or equal to 8,192 GB.
Enhanced or Performance Optimized: The new capacity must be greater than the current capacity and less than or equal to 32,768 GB.
If you expand the cache capacity of a subscription iSCSI gateway, you are redirected to the cache disk buy page after you click OK. On the cache disk buy page, change the cache capacity to the expected size and complete the payment. Cache scaling is automatically performed after you complete the payment.
For example, if the current cache disk is an ESSD PL1 cache disk and you want to increase the cache capacity from the current size of 100 GB to 200 GB, change the cache capacity of the ESSD PL1 cache disk to 200 GB and complete the payment.