Ideal restoration throughput rate with LTO4 drive

[Anthony_Kim]

Hi,

I wonder what throughput rate for restoration is reasonable under following system environments.

Server Hardware : HP ML370G6
OS : Windows 2003 server
Destination disk : RAID 5
Device interface to the Backup Drive : SAS(Serial Attached SCSI) Controller
Backup Device : HP 1840 LTO4 drive
Backup Software : BE V12.5

Here are my restoration result 

A retoration test to the destination disk(RAID 5) :  the the throughput rate was only 455MB/Min
A retoration test to the destination disk(RAID 0 + 1) :  the the throughput rate was 922MB/Min

The backup performance was quite reasonable on this system environments, the backup throughput rate was 4.9GB/Min,so I think all the systems/software(server hardware, backup device, and any configuration on Backup software) are working well. 

I wonder this restoration performance(455MB/Min) is reasonable or not. 

Thanks,
Anthony 

[teiva-boy]

 You cant compare the write performance of RAID 5 to RAID 10.  It's just not apples to apples.



But that restore speed is adequate as far as I can tell.

[Anthony_Kim · Accepted solution]

The root cause of this restoration performance issue was not "Write Cache" enabled on the array accelerator. With the latest array controller, we can enable the write cache even there is no BBWC(Battery pack) on the array controller. However, with the somehow old array contorlloer, we can't enable the write cache in case there is no BBWC on the controller.
Once I enabled the write cache with the cache ratio, 50% read / 50% write, the restoration performance has been encreased from 455MB/Min to 1,400MB/Min. This is a really remarkabe enhancement I think.