Dell EqualLogic PS6210XS EqualLogic Group Manager Administrator s Guide PS Ser - Page 211

NOTE: • The NAS clusterwide default values are applied when new containers are created. • If you select the Container thin provisioning default checkbox, ensure that you click the Save all changes icon afterward. If you do not, updates from the array will clear your selection. Thin-Provisioned Container Attributes Thin-provisioned containers have the following characteristics: • Minimum reserve is 0% to 99%. The default is 0%. • Maximum size for thin-provisioned container is 500TB. • The amount of space reserved for a container is either the minimum reserve or the actual used space, whichever is larger. • Space consumption grows linearly with used space when usage exceeds the minimum reserve. Disable Thin Provisioning on a Container To disable thin provisioning on a container: 1. Select the NAS container. 2. Click Modify Settings. 3. Click the Space tab. 4. Clear the Thin Provision checkbox. The space reservation slider is now cleared. 5. Click OK. About Data Rehydration Rehydration is the process whereby data that has been compressed becomes decompressed and readily accessible. Rehydration happens automatically and occurs as necessary to provide access to compressed data. Whenever data is vacated from one group member to another, any compressed data is automatically rehydrated during that process. NOTE: Rehydrating data affects performance and disk storage space utilization, because the data blocks are rendered on the disk in their original form. When you disable data reduction, data remains in its reduced state during subsequent read operations by default. You can also enable rehydrate-on-read when you disable data reduction. Enabling rehydrate-on-read causes a rehydration (a reversal of data reduction) of data on subsequent read operations. You cannot rehydrate an entire NAS container unless you read the entire container. NOTE: Neither data reduction nor data rehydration occurs on containers with less than 5GB of free space. Rehydrate on Read with User Quotas If you defined user quotas based on logical space utilization, those quotas remain in force throughout rehydration of the reduced data. For example, if three users have stored identical files of 3GB each, then after applying data reduction, only one physical copy will remain, thus consuming 3GB rather than 9GB. If each user has a user quota set to 4GB, then each of them can store only 1GB of additional data. Enable Rehydrate on Read NOTE: You must be logged in as grpadmin to enable rehydrate-on-read on an existing NAS container. 1. Click NAS, expand NAS Clusters and Local Containers, and then select the NAS container name. 2. In the Activities panel, click Modify settings to open the dialog box. 3. Click the Data Reduction tab. 4. Clear the Enable data reduction checkbox to display the Rehydrate on read option. 5. Select the Rehydrate on read checkbox, and click OK. 6. In the confirmation window, click Yes. NAS Container Operations 211