HP Storage Mirroring Software - Manual (Page 635)

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Action State Description
Automatic Action
Taken for Scheduled
and Automatic
Snapshots
User Interaction
Required for
Manual
Snapshots
Snapshot
Reverted
Good
or
Bad
The data on the
target no longer
matches the data
on the source
because a
snapshot has
been applied on
the target. This
does not
necessarily mean
that the data on
the target is bad. Scheduled and
automatic snapshots
will be delayed until a
restore is completed or
the Snapshot Reverted
state is overruled by a
mirror. Once the
restoration or mirror is
complete, automatic
and scheduled
snapshots will occur
normally. Restore the target
data back to the
source or overrule
the Snapshot
Reverted state by
performing a
mirror. Once the
restoration or
mirror is complete,
manual snapshots
can be taken
normally.
Restore
Complete
Good
Because the
restoration is
complete, the data
on the source and
target is
synchronized.
Scheduled and
automatic snapshots
will occur normally. Manual snapshots
can be taken
normally.
To be completely assured that your data on the target is good, automatic and scheduled
snapshots only occur when the data is in a good Storage Mirroring Recover state.
However, manual snapshots can be taken during any state. There are instances when
you may want to take a manual snapshot, even if the target data is in a bad state. For
example, if you drop an operation, that does not necessarily mean your data on the
target is corrupt or the target would be unable to stand in for the source in the event of a
failure. A snapshot of a bad state may be useful and usable, depending on your
environment. If your source is a file server and an operation has been dropped, it is just
one user file that is out-of-date. All of the remaining target files are intact and can be
accessed in the event of a failure.
However, if your source is an application server and an operation has been dropped,
that one file could cause the application not to start on the target in the event of a failure.
In these cases, manual snapshots of a bad state depend on the context of your
environment.