Couchbase delete data after warning message

We have a problem on our couchbase, when the warning message below is displayed, we can see that data of the bucket seems to be deleted, and data of other bucket in the same server node are flushed too.

The problem is that data seems to be persisted on the disk, but can’t be accessed ? Why ?
As I understand the mechanism of couhbase, data are in the RAM and persisted when ram is full. But when an access is requested, data is mounted in RAM no ?

the configuration is on one server node with 4Gb of RAM, and nearly 2 for this bucket.

Maybe its a problem of configuration from our team, but we all have the same issue when the message is displayed.

Could you give more details as to why you think the data cannot be accessed?

Data is always persisted to disk; however hot (recently accessed) data is automatically cached in RAM, up to the Bucket RAM quota.

When I request a data in a bucket that I’m sure it exists. My webservice answer is a "No Content"
Like if couchbase doesn’t check its persisted data to find the document.

Ok so my understanding of couchbase mechanism is correct thanks :smiley: