enable Drive Array Accelerator

[Wayne Glabais]

Receiving Drive Array Accelerator status = not configured.

Can I configure this "on the fly" using ACU without negatively impacting my server environment ?

OS=Windows 2003/Active Directory

[Oleg Koroz]

In general it designed to do from O/S when System Up and Running or from Smart Start CD. As fare as un-configured seems it asking to set Read write Options & Expand and Rebuild Priority. Normally it should not ask you unless battery was low or any other changes. Verify your Settings and check Firmware for array controller. http://h18000.www1.hp.com/support/files/storage/us/index.html

[Wayne Glabais]

I looked into the configuration of the array with the ACU utility. This may have been an oversite, as the checkbox beside "enable array accelerator" has not been checked.

Can I simply enable the accelerator or will this have a negative impact on the array ?

Regards, Wayne

[Oleg Koroz]

You should able change when System up and running it planned to do from O/S, however under heavy load it possibly to cause system to hung or crush. Once again we don't know actual reason why it gave error? So if your box 100% healthy there should be no problem.

[Wayne Glabais]

The error is generated only on a restart. I would assume that this is a normal occurance if the Array Accelerator is not configured.
There is very little utilization of this server so I'm not too concerned about load.
I suppose if the option is available in the Windows interface of the ACU that HP meant for it to be changed there, I'm just not certain if that will adversly effect the array.

Have you experienced enabling this on the fly ?

Thanks, Wayne

[Oleg Koroz]

For your practice you can set to 100% read 0% Write for First Time, where those setting by defaults even if not selected, after you can change if BBWC used.

Here is something from actual white Papers:
....... The read/write ratio is adjustable from 100% read or write to any mix in between. The ratio is usually set during configuration, but can be set at any time using the Array Configuration Utility.....

[John Marinov]

*PROVIDED* the battery for the array controller is installed and in good condition, you can enable the array accelerator at any time.

You can also turn it off for specific logical volumes within an array -depending on the model of array controller.

You can split the proportion of memory on the array controller allocated to read vs write. I recommend 75/25 read/write, but tune it based on the performance figures that Insight Manager gives.

[Colin_29]

You have not said what Array Controller you are using. It must have a battery backed cache to enable write caching. Once the battery is fully charged you will be able to change the ratio. The actual ratio that you employ will depend on the use of the server (are the applications read or write intensive?). This may be changed at any time "on the fly".

[Wayne Glabais]

The controller is a Smart Array 5i

[Colin_29]

The DL 360 G2 server is the only server which has a battery connector for the optional upgrade, the BBWC Enabler, for the Smart Array 5i controller. If you do not have this model or you have not installed the optional upgrade then you will no have Battery Backed Write Cache and will therefore only be able to utilise read cache.

The "5i plus" is different but you still require the optional upgrade to use write cache.