How you plan to create your aggregates and FlexVol volumes, traditional volumes, qtrees, or LUNs depends on your requirements and whether your new version of Data ONTAP is a new installation or an upgrade from Data ONTAP 6.5.x or earlier. For information about upgrading a NetApp storage system, see the Data ONTAP 7.1 Upgrade Guide.
If you purchased a new storage system with Data ONTAP 7.0 or later installed, the root FlexVol volume (vol0) and its containing aggregate (aggr0) are already configured.
The remaining disks on the storage system are all unallocated. You can create any combination of aggregates with FlexVol volumes, traditional volumes, qtrees, and LUNs, according to your needs.
To maximize the storage capacity of your storage system per volume, configure large aggregates containing multiple FlexVol volumes. Because multiple FlexVol volumes within the same aggregate share the same RAID parity disk resources, more of your disks are available for data storage.
You can set up a RAID-level mirrored aggregate to contain volumes whose users require guaranteed SyncMirror data protection and access. SyncMirror replicates the volumes in plex0 to plex1. The disks used to store the second plex can be up to 30 km away if you use MetroCluster. If you set up SyncMirror replication, plan to allocate double the number of disks that you would otherwise need for the aggregate to support your users. For information about MetroClusters, see the Cluster Installation and Administration Guide.
All volumes contained in a mirrored aggregate are in a SyncMirror relationship, and all new volumes created within the mirrored aggregate inherit this feature. For more information on configuring and managing SyncMirror replication, see the Data ONTAP Online Backup and Recovery Guide.
If you set up SyncMirror replication, plan to allocate double the disks that you would otherwise need for the aggregate to support your users.
When you create an aggregate, you can control the size of a RAID group. Generally, larger RAID groups maximize your data storage space by providing a greater ratio of data disks to parity disks. For information on RAID group size guidelines, see Larger versus smaller RAID groups.
Data ONTAP supports two levels of RAID protection, which you can assign on a per-aggregate basis: RAID4 and RAID-DP.
For more information on RAID4 and RAID-DP, see Levels of RAID protection.
When technicians install Data ONTAP on your storage system, they create a root volume named vol0. The root volume is a FlexVol volume, so you can resize it. For information about the minimum size for a FlexVol root volume, see the section on root volume size in the System Administration Guide. For information about resizing FlexVol volumes, see Resizing FlexVol volumes.
To share the storage capacity of your disks using the SharedStorageTM feature, you must decide whether you want to use the vFiler no-copy migration functionality. If so, you must configure your storage using traditional volumes. If you also want to take advantage of the migration software feature using SnapMover to reassign disks from a CPU-bound storage system to an underutilized storage system, you must have licenses for the MultiStore® and SnapMover® features. For more information, see SharedStorage.
The SnapLock feature enables you to keep a permanent snapshot by writing new data once to disks and then preventing the removal or modification of that data. You can create and configure a special traditional volume to provide this type of access, or you can create an aggregate to contain FlexVol volumes that provide this type of access. If an aggregate is enabled for SnapLock, all of the FlexVol volumes that it contains have mandatory SnapLock protection. For more information, see the Data Protection Online Recovery and Backup Guide.
Disk sanitization is a Data ONTAP feature that enables you to erase sensitive data from storage system disks beyond practical means of physical recovery. Because data sanitization is carried out on the entire set of disks in an aggregate, configuring smaller aggregates to hold sensitive data that requires sanitization minimizes the time and disruption that sanitization operations entail.You can create smaller aggregates and traditional volumes whose data you might have reason to sanitize at periodic intervals. For more information, see Sanitizing disks.
You can create up to 100 aggregates per storage system, regardless of whether the aggregates contain FlexVol volumes or traditional volumes.
You can use the aggr status command or FilerView (by viewing the System Status window) to see how many aggregates exist. With this information, you can determine how many more aggregates you can create on the storage system, depending on available capacity. For more information about FilerView, see the System Administration Guide.
You can create up to 200 volumes per storage system. However, you can only create up to 100 traditional volumes because of the 100 aggregates per storage system limit. You can use the vol status command or FilerView (Volumes > Manage > Filter by) to see how many volumes exist, and whether they are FlexVol volumes or traditional volumes. With this information, you can determine how many more volumes you can create on that storage system, depending on available capacity.
Consider the following example. Assume you create:
You now have a total of:
Thus, the storage system is well under the maximum limits for either aggregates or volumes.
If you have a combination of FlexVol volumes and traditional volumes, the 100-maximum limit of aggregates still applies. If you need more than 200 user-visible file systems, you can create qtrees within the volumes.
When planning the setup of your FlexVol volumes within an aggregate, consider the following issues.
FlexVol volumes have different best practices, optimal configurations, and performance characteristics compared to traditional volumes. Make sure you understand these differences and deploy the configuration that is optimal for your environment.
For information about deploying a storage solution with FlexVol volumes, including migration and performance considerations, see the technical report Introduction to Data ONTAP Release 7G (available from the NetApp Library at http://www.netapp.com/tech_library/ftp/3356.pdf).
Setting a maximum volume size does not guarantee that the volume will have that space available if the aggregate space is oversubscribed. As you plan the size of your aggregate and the maximum size of your FlexVol volumes, you can choose to overcommit space if you are sure that the actual storage space used by your volumes will never exceed the physical data storage capacity that you have configured for your aggregate. This is called aggregate overcommitment. For more information, see Aggregate overcommitment.
During volume creation you can specify the language character set to be used.
You can size your FlexVol volumes for convenient volume-wide data backup through SnapMirror, SnapVault®, and Volume Copy features. For more information, see the Data ONTAP Online Backup and Recovery Guide.
Many database programs enable data cloning, that is, the efficient copying of data for the purpose of manipulation and projection operations. This is efficient because Data ONTAP allows you to create a duplicate of a volume by having the original volume and clone volume share the same disk space for storing unchanged data. For more information, see Cloning FlexVol volumes.
If you upgrade to Data ONTAP 7.0 or later from a previous version, the upgrade program preserves all of your existing volumes as traditional volumes.
You can create traditional volumes and aggregates whose disks you intend to physically transport from one storage system to another. This ensures that a specified set of physically transported disks will hold all the data associated with a specified volume and only the data associated with that volume. For more information, see Physically transporting traditional volumes.
Within a volume you have the option of creating qtrees to provide another level of logical file systems. This is especially useful if you are using traditional volumes. Some reasons to consider setting up qtrees include:
Up to 4,995 qtrees--that is 4,995 virtually independent file systems--are supported per volume. For more information see Chapter 7, Qtree Management.
Qtrees support a sophisticated file and space quota system that you can use to apply soft or hard space usage limits on individual users, or groups of users. For more information see Chapter 8, Quota Management.
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Last updated: 01-Dec-2005 16:51:22