Change settings for a volume
You can change a volume’s settings such as its name, host assignment, segment size, modification priority, caching, and so on.
The volume you want to change is in Optimal status.
Select the volume that you want to change, and then select View/Edit Settings.
The Volume Settings dialog box appears. The configuration settings for the volume you selected appear in this dialog box.
Select the Basic tab to change the volume’s name and host assignment.
Displays the name of the volume. Change the name of a volume when the current name is no longer meaningful or applicable.
Displays the reported and allocated capacity for the selected volume.
Reported capacity and allocated capacity are the same for thick volumes, but are different for thin volumes. For a thick volume, the physically allocated space is equal to the space that is reported to the host. For a thin volume, reported capacity is the capacity that is reported to the hosts, whereas allocated capacity is the amount of drive space that is currently allocated for writing data.
Pool / Volume group
Displays the name and RAID level of the pool or volume group. Indicates whether the pool or volume group is secure-capable and secure-enabled.
Displays the volume assignment. You assign a volume to a host or host cluster so it can be accessed for I/O operations. This assignment grants a host or host cluster access to a particular volume or to a number of volumes in a storage array.
Assigned to — Identifies the host or host cluster that has access to the selected volume.
LUN — A logical unit number (LUN) is the number assigned to the address space that a host uses to access a volume. The volume is presented to the host as capacity in the form of a LUN. Each host has its own LUN address space. Therefore, the same LUN can be used by different hosts to access different volumes.
For NVMe interfaces, this column displays Namespace ID. A namespace is NVM storage that is formatted for block access. It is analogous to a logical unit in SCSI, which relates to a volume in the storage array. The namespace ID is the NVMe controller’s unique identifier for the namespace, and can be set to a value between 1 and 255. It is analogous to a logical unit number (LUN) in SCSI.
Displays the identifiers for the selected volume.
World-wide identifier (WWID) — A unique hexadecimal identifier for the volume.
Extended unique identifier (EUI) — An EUI-64 identifier for the volume.
Subsystem identifier (SSID) — The storage array subsystem identifier of a volume.
Select the Advanced tab to change additional configuration settings for a volume in a pool or in a volume group.
Application & workload information
During volume creation, you can create application-specific workloads or other workloads. If applicable, the workload name, application type, and volume type appears for the selected volume.
You can change the workload name if desired.
Quality of Service settings
Permanently disable data assurance — This setting appears only if the volume is Data Assurance (DA)-enabled. DA checks for and corrects errors that might occur as data is transferred through the controllers down to the drives. Use this option to permanently disable DA on the selected volume. When disabled, DA cannot be re-enabled on this volume.
Enable pre-read redundancy check — This setting appears only if the volume is a thick volume. Pre-read redundancy checks determine whether the data on a volume is consistent any time a read is performed. A volume that has this feature enabled returns read errors if the data is determined to be inconsistent by the controller firmware.
Defines the controller that is designated to be the owning, or primary, controller of the volume.
Controller ownership is very important and should be planned carefully. Controllers should be balanced as closely as possible for total I/Os.
Shows the setting for segment sizing, which appears only for volumes in a volume group. You can change the segment size to optimize performance.
Allowed segment size transitions — System Manager 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.
Shows the setting for modification priority, which only appears for volumes in a volume group.
The modification priority defines how much processing time is allocated for volume modification operations relative to system performance. You can increase the volume modification priority, although this might affect system performance.
Move the slider bars to select a priority level.
Modification priority rates — The lowest priority rate benefits system performance, but the modification operation takes longer. The highest priority rate benefits the modification operation, but system performance might be compromised.
Shows the caching setting, which you can change to impact the overall I/O performance of a volume.
Shows the SSD Cache setting, which you can enable on compatible volumes as a way to improve read-only performance. Volumes are compatible if they share the same Drive Security and Data Assurance capabilities.
The SSD Cache feature uses a single or multiple Solid State Disks (SSDs) to implement a read cache. Application performance is improved because of the faster read times for SSDs. Because the read cache is in the storage array, caching is shared across all applications using the storage array. Simply select the volume that you want to cache, and then caching is automatic and dynamic.
System Manager changes the volume’s settings based on your selections.
Selectto view the progress of the change operations that are currently running for the selected volume.