Dell Lifecycle Controller GUI v2.30.30.30 User's Guide

Use this page to specify the values for the following virtual drive attributes:

• Size — Specify the size of the virtual drive.
• Stripe Element Size — Select the stripe element size. The stripe element size is the amount of drive space a stripe consumes on each physical-disk drive in the stripe. The Stripe Element Size list may contain more options than initially displayed on the screen. Use the up arrow and down arrow keys to view all available options.
• Read Policy — Select the read policy:
  • Read Ahead — The controller reads sequential sectors of the virtual drives when seeking data. The Read Ahead policy may improve system performance if the data is written to sequential sectors of the virtual drives.
  • No Read Ahead — The controller does not use the Read Ahead policy. The No Read Ahead policy may improve system performance, if the data is random and not written to sequential sectors.
  • Adaptive Read Ahead — The controller initiates the Read Ahead policy only if the most-recently-read requests accessed sequential sectors of the disk drive. If the most-recently-read requests access random sectors of the disk drive, then the controller uses the No Read Ahead policy.
• Write Policy — Select the write policy.
  • Write Through — The controller sends a write-request-completion signal only after the data is written to the disk drive. The Write Through policy provides better data security than the Write Back policy, because the system assumes that the data is available only after it has been written to the disk drive.
  • Write Back — The controller sends a write-request completion signal as soon as the data is in the controller cache, but has not yet been written to the disk drive. The Write Back policy may provide faster 'write' performance, but it provides less data security, because a system failure can prevent the data from being written to the disk drive.
  • Force Write Back — The write cache is enabled regardless of whether the controller has an operational battery. If the controller does not have an operational battery, data loss may occur in the event of a power failure.
• Disk Cache Policy— Select the write policy.
  • Enabled — The controller enables physical disk cache setting while creating virtual disks.
  • Disabled —The controller disables physical disk cache setting while creating virtual disks.
• Assign a Hot Spare Disk if available — Select this option to assign a hot spare to the virtual drive. A hot spare is an unused backup physical disk drive that is used to rebuild data from a redundant virtual drive. A hot spare can be used only with a redundant RAID level. Hot spares also have physical disk-drive size requirements. The hot spare must be as large as or bigger than the smallest physical disk-drive included in the virtual drive. If the RAID level and physical disk-drive availability do not meet these requirements, a hot spare is not assigned.
  • NOTE: Assign a hot spare only from disk drives populated across slots 0–3 of the system. For slot information, see the Dell PowerEdge Owner's manual at dell.com/poweredgemanuals.
• Hot Spare Disk — Select a disk that is used as a hot spare. Only one dedicated hot spare is supported in Lifecycle Controller.
• Secure Virtual Disk — Select to secure the virtual drive using the controller’s security key.
  • NOTE: The secure virtual drive is created only if the controller security key is created and the selected disks are Self-Encrypting Drives (SEDs).