SmartCache

[MTID]

Hi all,

I set up SmartCache on my ML350 ProLiant.

I installed 2xSSD 480GB in RAID 1. I set all the space for caching, in write-back mode.

At the end of the configuration, the SSA notifies 2 message: the first is normal message indicating that HP SmartCache is enabled on Smart Array P440ar. The second message indicates that the cache on LD1 (logical drive 1)  cannot be cleared because it uses the write-back mode for HP SmartCache.

What does this message mean?

Thank you for your reply.

MTID

[DeepakJajware · Accepted solution]

Hello 

Greetings  ! 

Yes these are normal messages which you are getting on the server. 

I guess you are more concerened on the 2nd Message which is coming as " The second message indicates that the cache on LD1 (logical drive 1)  cannot be cleared because it uses the write-back mode for HP SmartCache. " 

Choice of write-through or write-back cache  is for Gen9 servers only. 

Write-back is a caching method where data is not copied to the data volume until absolutely necessary.
Write-back might accelerate performance in comparison to the write-through policy by reducing the
number of write operations to data volumes. The performance improvement can involve the risk of lost
data if the cache volume fails..

A write-back SmartCache cannot be deleted until it is converted to a write-through SmartCache using the
Modify Caching Write Policy button

. This conversion forces user data to be flushed from the
SmartCache volume to the primary hard drive volume, to avoid data loss when the SmartCache is
deleted.

CAUTION: Specifying the write-back cache write policy could result in data loss in the event
of failure of the cache volume. When using a RAID 0 cache volume, a single SSD failure might
result in data loss. 

Hope this will help you 

Thank you.