Ready for {reading|writing}, idle

Sometimes NetWorker adminsitrators find themselves gnashing their teeth over the following device/media status messages:

• ready for reading, idle

or

• ready for writing, idle

Now, we often see these messages briefly during normal backup, cloning, recovery or staging operations. Where the teeth gnashing tends to start is when a device/volume sits in that state for an extended period of time.

The problem I find is that when a device/volume appears to be wedged in this state people start looking at the wrong things. 99.9999% of the time this message does not indicate there’s an issue with the device or volume that is “ready/idle”, but there’s an issue elsewhere.

This message means: “the device is ready, and waiting, but currently inactive”. So you have to ask yourself when a device/volume is wedged in this position – what is it waiting for? This is why the answer isn’t to investigate that device or volume, but to look at other activity.

Consider the following examples:

• In a disk to tape cloning operation, a disk backup unit may be reported as “ready for reading, idle”. Chances are NetWorker is waiting for something to clone to. So check to see why media isn’t being made available for writing.
• In a tape to tape cloning operation, a tape device unit may be reported as “ready for writing, idle”. So that means that it’s waiting for something to read from – maybe something is preventing the mount of the read volume? Or maybe the read volume is being read from for something else? (E.g., a recovery).

In very, very few cases the ready/idle state is the default of the device that’s in the idle state, but my recommendation is that if you’ve got a device wedged in this state, you need to look elsewhere to see why NetWorker isn’t able to send data to, or retrieve data from the device/volume.