The ServeRAID M5015 SAS/SATA Controller for IBM System x is the next-generation 6 Gbps SAS 2.0 RAID controller. The adapter has two internal mini-SAS connectors to control up to 32 devices and support global and dedicated hot-spare drives. The ServeRAID M5015 provides additional performance advantages of an extended cache and a standard battery backup unit.
Auto-resume on array rebuilt or array reconstruction after loss of system power
Auto-resume uses non-volatile NVRAM to save rebuild progress during a host reboot or power failure to automatically resume from the last checkpoint. Auto-resume will ensure data integrity is maintained through the process. The card supports a number of features that are able to be implemented without rebooting the server. Applications such as email and web server benefit from avoiding downtime during transition.
Online Capacity Expansion
Online Capacity Expansion (OCE) allows the capacity of a virtual disk to be expanded by adding new physical disks or making use of unused space on existing disks, without requiring a reboot.
Online RAID Level Migration
Online RAID Level Migration (also known as logical drive migration) provides the ability to migrate a virtual disk from any RAID level to any other RAID level without requiring a reboot. System availability and application functionality remain unaffected.
Consistency check for background data integrity
Consistency Check verifies that all stripes in a virtual disk with a redundant RAID level are consistent. The consistency check will mirror data when an inconsistent stripe is detected for a RAID 1 and recreating the parity from the peer disks when in the case of a RAID 5 or RAID 6. Consistency checks can be scheduled to take place periodically.
Patrol Read for media scanning and repairing
Patrol read is a background sentry service designed to proactively discover and correct media defects (bad sectors) that arise normally as a disk drive ages. The service issues a series of verify commands and if a bad block is discovered, the card's firmware will use RAID algorithms to recreate the missing data and remap the sector to a good sector. The task is interruptible based on controller activity and host operations. The firmware also provides an interface where the patrol read task can be initiated, set up for continuous operation, and terminated from a management application. Patrol read can be activated by manual command or automatically.
