Fault Tolerance; Self-Monitoring And Reporting Technology; Native Command Queuing; 4Kn Drives Support - Dell PowerEdge S130 User Manual

Fault tolerance

The following fault tolerance features are available with the PERC S130:
• Physical disk failure detection (automatic).
• Virtual disk rebuild using hot spares (automatic, if the hot spare is configured for this feature).
• Parity generation and checking (RAID 5 only).
• Hot-swap manual replacement of a physical disk without rebooting the system (only for systems with a backplane that allows
hot-swapping).
If one side of a RAID 1 (mirror) fails, data can be rebuilt by using the physical disk on the other side of the mirror.
If a physical disk in RAID 5 fails, parity data exists on the remaining physical disks, which can be used to restore the data to a new,
replacement physical disk configured as a hot spare.
If a physical disk fails in RAID 10, the virtual disk remains functional and data is read from the surviving mirrored physical disk(s). A
single disk failure in each mirrored set can be sustained, depending on how the mirrored set fails.

Self-Monitoring And Reporting Technology

The Self-Monitoring and Reporting Technology (SMART) feature monitors certain physical aspects of all motors, heads, and physical
disk electronics to help detect predictable physical disk failures. Data on SMART compliant physical disks can be monitored to
identify changes in values and determine whether the values are within threshold limits. Many mechanical and electrical failures
display some degradation in performance before failure.
A SMART failure is also referred to as predicted as failure. There are numerous factors that are predicted physical disk failures, such
as a bearing failure, a broken read/write head, and changes in spin-up rate. In addition, there are factors related to read/write surface
failure, such as seek error rate and excessive bad sectors.
NOTE: For detailed information on SCSI interface specifications, see t10.org and for detailed information on SATA
interface specifications, see t13.org.

Native command queuing

Native Command Queuing (NCQ) is a command protocol used by SATA physical disks, which are supported on the S130 controller.
NCQ allows the host to provide multiple input/output requests to a disk simultaneously. The disk decides the order to process the
commands to achieve maximum performance.

4Kn drives support

S130 supports 4Kn sector size, which enables disks of 4096 bytes as sector size. This is in addition to support of 512 byte sector
size.
NOTE: Ensure that you use only the S130 UEFI configuration utility to configure 4Kn sector drives during pre-boot.
NOTE: Mixing 512–byte native and 512–byte emulated drives in a virtual disk is allowed, but mixing 512–byte and 4 KB
native drives in a virtual disk is not allowed.

Physical disk write cache policy

Physical disk write cache policy feature enables the disk to cache the data first, and then the cached data is written to the storage
device in the background. For more information about managing the physical disk write cache policy, see
write cache policy.
NOTE: You can use UEFI or Option ROM (OPROM) to configure the physical disk write cache policy.
Managing the physical disk
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