Question regarding "Write Back"

Hi there,

I have a technical question regarding the "Write Back" Feature of logical volumes within Open-E DSS V6. We have a 3ware 9650SE RAID Controller, which is powered by a BBU, so we have the write cache enabled on the controller. Now the question:

Our volumnes are currently in WRITE THROUGH mode. Can I safely(!!!) switch them to WRITE BACK mode, because WRITE BACK means that in case of powerlos the BBU of the RAID controller will keep the cache alive, or means WRITE BACK the cache of the Open-E system itself, which would be lost...

We want to bring up volume replication with iSCSI failover in some weeks, and I want to be 100% sure that if the primary goes down no data is lost in case of secondary comes up. Is this possible with WRITE BACK and a RAID controller that has a BBU on it?

The help of Open-E doesn't answer this question.

Thanks in advance,
Tim

Hi there,

As the message suggests when you go to enable Write Back mode, I would suggest you invest in a decent UPS to power your SAN. This will ensure Open-E has time to gracefully flush its cache and shut down in the event of a power failure.

Best regards

TFZ

I don't believe you should enable write back cache if you are intending to use iSCSI failover, as the pop-up dialog suggests.

Best regards

Alex