Step 3: Add or edit volumes

In the third step, you define the volume configuration.

Because volumes are created from pools or volume groups, the pool or volume group you select must have sufficient free capacity.
To create a Data Assurance (DA)-enabled volume, the host connection you are planning to use must support DA.
Note
DA is not supported by iSCSI over TCP/IP.
- If you want to create a DA-enabled volume, select a pool or volume group that is DA capable (look for Yes next to "DA" in the pool and volume group candidates table).
- DA capabilities are presented at the pool and volume group level. DA protection checks for and corrects errors that might occur as data is transferred through the controllers down to the drives. Selecting a DA-capable pool or volume group for the new volume ensures that any errors are detected and corrected.
- If any of the host connections on the controllers in your storage array do not support DA, the associated hosts cannot access data on DA-enabled volumes.
To create a secure-enabled volume, a security key must be created for the storage array.
- If you want to create a secure-enabled volume, select a pool or volume group that is secure capable (look for Yes next to "Secure-capable" in the pool and volume group candidates table).
- Drive security capabilities are presented at the pool and volume group level. Secure-capable drives prevent unauthorized access to the data on a drive that is physically removed from the storage array. A secure-enabled drive encrypts data during writes and decrypts data during reads using a unique encryption key.
- A pool or volume group can contain both secure-capable and non-secure-capable drives, but all drives must be secure-capable to use their encryption capabilities.

You create volumes from eligible pools or volume groups, which are shown in the Add/Edit Volumes dialog box. For each eligible pool and volume group, the number of drives available and the total free capacity appears.

For some application-specific workloads, each eligible pool or volume group shows the proposed capacity based on the suggested volume configuration and shows the remaining free capacity in GiB. For other workloads, the proposed capacity appears as you add volumes to a pool or volume group and specify the reported capacity.

Choose one of these actions based on whether you selected Other or an application-specific workload in the previous step:

Other – Click Add new volume in each pool or volume group that you want to use to create one or more volumes.

Field	Description
Volume Name	A volume is assigned a default name during the volume creation sequence. You can either accept the default name or provide a more descriptive one indicating the type of data stored in the volume.
Reported Capacity	Define the capacity of the new volume and the capacity units to use (MiB, GiB, or TiB). For Thick volumes, the minimum capacity is 1 MiB, and the maximum capacity is determined by the number and capacity of the drives in the pool or volume group. Keep in mind that storage capacity is also required for copy services (snapshot images, snapshot volumes, volume copies, and remote mirrors); therefore, do not allocate all of the capacity to standard volumes. Capacity in a pool is allocated in 4-GiB increments. Any capacity that is not a multiple of 4 GiB is allocated but not usable. To make sure that the entire capacity is usable, specify the capacity in 4-GiB increments. If unusable capacity exists, the only way to regain it is to increase the capacity of the volume.
Segment Size	Shows the setting for segment sizing, which only appears for volumes in a volume group. You can change the segment size to optimize performance. Allowed segment size transitions – The system determines the segment size transitions that are allowed. Segment sizes that are inappropriate transitions from the current segment size are unavailable on the drop-down list. Allowed transitions usually are double or half of the current segment size. For example, if the current volume segment size is 32 KiB, a new volume segment size of either 16 KiB or 64 KiB is allowed. SSD Cache-enabled volumes – You can specify a 4-KiB segment size for SSD Cache-enabled volumes. Make sure you select the 4-KiB segment size only for SSD Cache-enabled volumes that handle small-block I/O operations (for example, 16 KiB I/O block sizes or smaller). Performance might be impacted if you select 4 KiB as the segment size for SSD Cache-enabled volumes that handle large block sequential operations. Amount of time to change segment size – The amount of time to change a volume's segment size depends on these variables: The I/O load from the host The modification priority of the volume The number of drives in the volume group The number of drive channels The processing power of the storage array controllers When you change the segment size for a volume, I/O performance is affected, but your data remains available.
Secure-capable	Yes appears next to "Secure-capable" only if the drives in the pool or volume group are secure-capable. Drive Security prevents unauthorized access to the data on a drive that is physically removed from the storage array. This option is available only when the Drive Security feature has been enabled, and a security key is set up for the storage array. A pool or volume group can contain both secure-capable and non-secure-capable drives, but all drives must be secure-capable to use their encryption capabilities.
DA	Yes appears next to "DA" only if the drives in the pool or volume group support Data Assurance (DA). DA increases data integrity across the entire storage system. DA enables the storage array to check for errors that might occur as data is transferred through the controllers down to the drives. Using DA for the new volume ensures that any errors are detected.

Application-specific workload – Either click Next to accept the system-recommended volumes and characteristics for the selected workload, or click Edit Volumes to change, add, or delete the system-recommended volumes and characteristics for the selected workload.

Field	Description
Volume Name	A volume is assigned a default name during the volume creation sequence. You can either accept the default name or provide a more descriptive one indicating the type of data stored in the volume.
Reported Capacity	Define the capacity of the new volume and the capacity units to use (MiB, GiB, or TiB). For Thick volumes, the minimum capacity is 1 MiB, and the maximum capacity is determined by the number and capacity of the drives in the pool or volume group. Keep in mind that storage capacity is also required for copy services (snapshot images, snapshot volumes, volume copies, and remote mirrors); therefore, do not allocate all of the capacity to standard volumes. Capacity in a pool is allocated in 4-GiB increments. Any capacity that is not a multiple of 4 GiB is allocated but not usable. To make sure that the entire capacity is usable, specify the capacity in 4-GiB increments. If unusable capacity exists, the only way to regain it is to increase the capacity of the volume.
Volume Type	Volume type indicates the type of volume that was created for an application-specific workload.
Segment Size	Shows the setting for segment sizing, which only appears for volumes in a volume group. You can change the segment size to optimize performance. Allowed segment size transitions – The system determines the segment size transitions that are allowed. Segment sizes that are inappropriate transitions from the current segment size are unavailable on the drop-down list. Allowed transitions usually are double or half of the current segment size. For example, if the current volume segment size is 32 KiB, a new volume segment size of either 16 KiB or 64 KiB is allowed. SSD Cache-enabled volumes – You can specify a 4-KiB segment size for SSD Cache-enabled volumes. Make sure you select the 4-KiB segment size only for SSD Cache-enabled volumes that handle small-block I/O operations (for example, 16 KiB I/O block sizes or smaller). Performance might be impacted if you select 4 KiB as the segment size for SSD Cache-enabled volumes that handle large block sequential operations. Amount of time to change segment size – The amount of time to change a volume's segment size depends on these variables: The I/O load from the host The modification priority of the volume The number of drives in the volume group The number of drive channels The processing power of the storage array controllers When you change the segment size for a volume, I/O performance is affected, but your data remains available.
Secure-capable	Yes appears next to "Secure-capable" only if the drives in the pool or volume group are secure-capable. Drive security prevents unauthorized access to the data on a drive that is physically removed from the storage array. This option is available only when the drive security feature has been enabled, and a security key is set up for the storage array. A pool or volume group can contain both secure-capable and non-secure-capable drives, but all drives must be secure-capable to use their encryption capabilities.
DA	Yes appears next to "DA" only if the drives in the pool or volume group support Data Assurance (DA). DA increases data integrity across the entire storage system. DA enables the storage array to check for errors that might occur as data is transferred through the controllers down to the drives. Using DA for the new volume ensures that any errors are detected.

To continue the volume creation sequence for the selected application, click Next, and go to Step 4: Review volume configuration.

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