AJA KONA LHI, Installation And Operation Manual

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For uncompressed 3G or HD, AJA recommends that at a minimum, the disk storage system
must be able to provide and maintain in excess of 300 MB/sec transfer rate from the Apple
computer to disk (read/write). There are a variety of system configurations and peripherals
that can provide this level of performance. KONA LHi users wishing to configure a storage for
a system should also be aware that raw benchmark numbers alone do not necessarily reflect
the performance of a drive solution. Other factors, such as drive seek time and controller
cache can also affect performance especially with regard to the bandwidth requirements of
3G, HD, and SD files.
About RAIDs
Redundant Array of Independent Disks, or RAID, is a group of hard drives that appears to the
host Power Mac as a single high-speed storage unit. RAID systems enable you to increase
storage capacity and get the performance, reliability, and data protection needed for video
production, but not possible from a single hard drive. RAID drives inside the array operate
simultaneously, increasing overall throughput. RAID technology is comprised of these
techniques (some or all):
•
Striping data across multiple drives for storage performance (RAID 0).
•
Mirroring for redundancy (RAID 1).
•
Parity for data protection (RAID 5 [plus others]).
Most RAID configurations, or RAID levels, combine these to provide a balance of protection
and performance.
Striping divides a logical drive into data blocks, or stripes, that are distributed across an array
of physical drives. Striping a set of disks improves storage performance because each drive
operates concurrently. However, striping alone, known as RAID level 0, offers no data
protection.
Mirroring involves writing identical copies of all data to a pair of physical drives. This results in
very high data reliability: If one drive fails, the data is still available on the remaining disk drive.
However, it also results in a storage efficiency of only 50 percent, because two physical drives
are required to achieve a single drive’s capacity. Mirroring alone is known as RAID level 1.
Parity provides data protection without requiring complete duplication of the drive contents.
In the event of a drive failure, parity information can be used with data on surviving drives to
reconstruct the contents of a failed drive. Parity data can be stored on a dedicated drive, as in
RAID 3, or distributed across an array of drives, as in RAID 5. Parity provides much greater
storage efficiency than mirroring—up to 85 percent for a set of seven drives.
Software For Striping
AJA recommends the Disk Utility software provided by Apple with OS X for creating and
striping RAIDs, including 3rd-party, SCSI, and Xserve RAIDs. It is very easy to use and has been
tested to work well. The utility can be found in
Macintosh HD/Applications/Utilities, where
“Macintosh HD” is the name of the system drive.
AJA KONA LHi and Fibre Channel RAID (Xserve or other)
For the optimum in disk storage with Final Cut Pro and AJA KONA LHi, we recommend a Fibre
Channel or SATA RAID array. Apple’s Xserve RAID, for example, holds up to 14 hot-swap Apple
Drive Modules—5.6TB of storage—in a rack-optimized 3U enclosure. Each 7200-RPM hard
drive connects to a dedicated ATA/100 drive channel, eliminating a traditional source of
bottlenecks and maximizing the 2Gb/s Fibre Channel host connection(s). By adding more
Xserve RAID systems, you’ll have very large expansion capabilities: A standard 42U rack can
hold over 78TB of Xserve RAID storage.
Note: When creating and striping an Xserve RAID for KONA LHi using the Apple Disk Utility
provided with OS X, use RAID 50 : in other words, the internal Xserve RAID drives are set up
as RAID 5; the Xserve RAID then shows up in Disk Utility as two drives (regardless of the
number of internal drives) which must be configured together as RAID 0. Apple calls this
configuration “RAID 50.”