ML150 G5 - Raid performance are ok ?

[IT Global Service]

I installed a fresh new server with sbs 2008 using the embedded raid controller configured with one raid1 array (port 1 - 2) and one single hd for backup on port 3.

All the hard disks are 160GB sata 300.
I disabled the cache-writing

I have some doubt on the controller performance. It seem slow.

I run DiskMark test on the system partition (c: - 60GB) and this is the results:

Test Size : 100 MB

Sequential Read : 65.058 MB/s
Sequential Write : 39.754 MB/s
Random Read 512KB : 31.579 MB/s
Random Write 512KB : 21.909 MB/s
Random Read 4KB : 0.497 MB/s
Random Write 4KB : 0.372 MB/s

Then, I run hdtune to have a visual idea of transfer and I noticed frequent performance fall (see the attachment).

Somebody could check my results and give an opinion ?

Thank you

[KarloChacon]

that's usually the recommendation to enable write caching to improve performance but I mean in controller BIOS not windows side


F8 to get into BIOS
Navigate to "Manage Arrays" and select the array you want in the "List of Arrays" Don't press "Enter" this will just show you a summary of your configuration. Instead do the following:
- Press (Ctrl + W) "Enable Write Cache" (Option)

[IT Global Service]

Hi Karlo and thank you for your "sunday" reply ! :-)

One more question:

if i enable the write-cache, and some disaster event happen (power failure, cpu or ram issues, etc..) is there any risk to compromise the hard disk data integrity ?

Thank you

[KarloChacon]

it was Saturday for...today is Sunday ;-)

well yes that's one of the risk since the cache for controller does not have any battery option but that data in the cache won't be compromised it is the same as having a p400 controller with no battery option but of course for the p400 you can buy the battery option and for the Embedded Sata there is no such option

[IT Global Service]

I live in Italy... for me was already Sunday when I wrote ! :-)

I'm not really sure to understood your reply.
How you sure noticed , my english is not a state of the art !

I don't understand why "data in the cache won't be compromised" if the controller have not battery backup for cache ?

In other words....

if in the controller cache there are data, power go down , when power come back again data are gone... or not ???

If yes, data on hard disk will be inconsinstency and when o.s. restart something could be broken.

Correct ?

If the server has ups , could this substitute the no backup battery of the controller ?

Thank you