Руководство Пользователя для Spectra Logic spectra t120

Chapter 10.  Best Practices for RXT Media

104

Choose a RAID level based on your risk tolerance as well as your capacity and 
performance needs. 

• RAID 0 provides the best performance, but no redundancy; a single disk drive 

failure results in data loss. 

• RAID 1 provides redundancy, but slower performance. If a primary or mirrored 

drive fails, data is still available on the alternate drive. When the failed drive is 
replaced, data is replicated (i.e. mirrored) to that drive to ensure full redundancy.

• RAID 5 can be viewed as midrange options for both performance and protection. 

Following are a few tips to achieve optimal performance from RXT. 

RXT is designed to achieve transfer rates of up to 110 MB/sec when configured as 
RAID 0 in an optimal environment (that is, with an optimal data source and optimal 
performance from the server connected to the RXT drive).

Due to different read and write processes that must occur for RAID 1 and RAID 5, the 
transfer rates for these configurations vary. 

RXT itself cannot be configured to alter performance; all performance tuning must be 
done with your operating system and backup software. To maximize performance with 
RXT, Spectra Logic recommends a 256KB block size (or larger) in your backup 
application. Block sizes smaller than this may show decreased performance.

Note: Block sizes larger than 256KB are not supported in Windows 

operating systems with IBM drivers.

Note: Block sizes should always be divisible by four (4).

Consult the documentation for your backup software for instructions on how to 
configure the block size setting and other performance tuning options.

In most backup environments, SCSI disconnects are already enabled, which optimizes 
backup performance. This setting should remain the same for RXT, since RXT has 
substantially slower SCSI throughput if SCSI disconnects are disabled. Consult your 
HBA’s user documentation for instructions on how to modify this option.