Edit External Volumes confirmation window

Item

Description

Parity Group ID

Displays parity group numbers.

Top LDEV ID

External volume's top LDEV ID.

Top LDEV Name

External volume's top LDEV name.

Cache Mode

  • Enable: Write data from the host is propagated asynchronously
  • Disable: Write data from the host is propagated synchronously

When nondisruptive migration is specified as the Attribute, the cache modes are displayed.

  • Through: Transfers write and read requests from the host to the external storage system. The local system's cache is not used.
  • Write Sync: Reflects write data from the host to the external storage system synchronously. If read or write is performed while data is being written to the external storage system, the read or write operation waits until the ongoing write operation is completed.
  • Check Condition : Indicates that write or read commands from the host were rejected.
  • Pending : Holds write and read commands from the host.

While cache mode operations are in progress, status is reported for cache mode changes.

  • (Changing): Transition to the displayed cache mode is in progress.
  • (Error): Transition to the displayed cache mode has failed and maintenance work is required.

See the planning topic in the Universal Volume Manager User Guide for more information.

Inflow Control

  • Enable: Limits or prevents write data from being written to cache memory when the write operation cannot be performed.
  • Disable: Allows write data to be written to cache when the write operation cannot be performed.

Path Mode

Displays the external path of the external volume.

  • Single: One external path is used, with alternate paths available in case of failure.
  • Multi: Multiple paths are used at the same time.
  • ALUA: Like Multi, all paths are used; however, they are not used when connected to ports in Passive status.

ALUA Permitted

Displays whether ALUA can be set as the Path Mode in the local storage system.

  • Enable: ALUA Mode is used.
  • Disable: ALUA Mode is not used.

Load Balance Mode

Displays I/O load balance system for external storage system.

  • Normal Round-robin: Performs load balance in round-robin system.
  • Extended Round-robin: Load balance system is automatically switched for sequential I/O and random I/O.
  • Disable: Performs I/O operation with a single path, without load balance.