Dot Hill Systems II 200 FC - Manual (Page 30)

1-10 SANnet II 200 FC, SATA, and SATA SE Array Installation, Operation, and Service Manual • March 2005
Caution –
You can mix disk drive capacity in the same chassis, but not spindle speed
(RPM). For instance, you can use 36-Gbyte and 73-Gbyte drives with no performance
problems if both are 10K RPM drives. Violating this configuration guideline leads to
poor performance.
In the event of a single disk drive failure, with the exception of RAID 0, the system
continues to service all I/O requests. Either mirrored data or parity data is used to
rebuild data from the failed drive to a spare drive, assuming one is assigned. If a spare
is not assigned, you must manually rebuild the array.
In the unlikely event that multiple drive failures occur within the same logical drive,
data that has not been replicated or backed up might be lost. This is an inherent
limitation of all RAID subsystems and could affect application programs.
An air management sled FRU is available for use when you remove a disk drive and
do not replace it. Insert an air management sled into the empty slot to maintain
optimum airflow through the chassis.
1.2.3.1 SANnet II 200 FC Array Disk Drives
The drives can be ordered in 36-Gbyte, 73-Gbyte, and 146-Gbyte sizes. 36-Gbyte
drives have a rotation speed of 15,000 RPM, 146-Gbyte drives have a rotation speed of
10,000 RPM, and 73-Gbyte drives are available with rotation speeds of 10,000 RPM
and 15,000 RPM.
1.2.3.2 SANnet II 200 SATA and SATA SE Array Disk Drives
The disk drives incorporate Serial ATA (SATA) technology. They are optimized for
capacity, but have performance levels approaching Fibre Channel performance levels.
The drives can be ordered in 250-Gbyte and 400-Gbyte sizes and have a rotation speed
of 7200 RPM.
1.2.4 Battery Module
The battery module is designed to provide power to system cache for 72 hours in the
event of a power failure. When power is reapplied, the cache is purged to disk. The
battery module is hot-swappable. Hot-swappable means that a live upgrade can be
performed. The FRU can be removed and replaced while the RAID array is powered
on and operational. The battery module is mounted on the I/O board with guide rails
and a transition board. It also contains the EIA-232 and DB9 serial interface (COM)
ports.