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TSS MINI Operations Manual
Page 101
Hard Disk Management
The TSS MINI Multi Format Video Server employs an advanced SAS controller that manages
the high-capacity hard disk array operating in a RAID-5 configuration. This design increases
system performance, and by storing parity data, can survive the complete loss of a drive in the
array without data loss.
The system brings a high level of reliability to SAS RAID through a switched architecture
that exceeds the reliability of standalone drive systems. The non-blocking switched architecture
isolates the drives from one another. Any drive failure makes that drive unavailable and the rest
of the storage system remains undisturbed. In addition, Advanced Data Protection checks all
drive commands to ensure that no command corruption has taken place over the entire data
path.
Some of the RAID-5 implementation features and benefits include:
Non-blocking switch technology with RAID-5 parity
On-board processor minimizes host CPU overhead
Easy-to-configure arrays
Dynamic sector repair for robust data protection
Accelerated RAID-5 writes
Easy drive replacement from front panel
About RAID 5
A RAID 5 configuration features the data striping of RAID 0, combined with the parity
benefits of RAID 4. Using a parity (exclusive OR) function, RAID 5 can tolerate the loss of
one drive. Parity information is distributed across all drives rather than being concentrated
on a single disk. This avoids throughput loss due to contention for the parity drive. Spare
drives can be used to rebuild an array after a drive is replaced.
RAID-5 capacity equals the size of drive times (number of drives -1). In addition, the array’s
storage efficiency increases with the number of disks; from 66.7 % for 3 drives to 75 % for
four drives: storage efficiency = (number of drives -1) X (number of drives).