13 Jan
2012
13 Jan
'12
2:56 p.m.
On Jan 13, 2012, at 6:51 PM, John R Pierce pierce@hogranch.com wrote:
On 01/13/12 3:46 PM, Ross Walker wrote:
You will need to publish these disks as straight through individual disks with write-through cache and use software RAID if the controllers can't communicate with each other.
write-through cache is not even good enough. if a given block is written through one of them, it will land on the disk, but it won't update the other controller cache, so the other controller could have stale data in its cache and if another read takes that path, it will get the old data, and things go downhill from there quickly.
And read-through too, bascially disable caching on the controllers.
-Ross