Article: 4610022

Service Advisory - Replay Agent Driver Update

AppAssure has identified a potential issue that may cause Replay to generate inconsistent snapshots. A driver update is available to address this issue and AppAssure recommends applying the update.

Issue

The newer generation of Microsoft operating systems (Microsoft Vista and above) introduced a concept of transacting file operations made available through Transactional NTFS (TxF). TxF plays an important role at many levels including allowing the ability to develop applications with improved platform and application stability. Applications may use TxF to group file changes together into a transaction. The transaction will guarantee that all changes happen or that none of them do. The transaction will also guarantee that applications outside the transaction won’t see the changes until they are committed. TxF requires VSS to ensure transactional consistency. Under some conditions, TxF may roll back the file system back into a consistent state. This rollback generates additional I/Os and may result in an unhealthy snapshot.

For application servers such as Exchange and SQL, Replay’s integrity algorithms continue to check the recoverability of the application by identifying unhealthy snapshots. For non-application servers and system disks, unhealthy snapshots manifest themselves with problems during a BMR process or an export to virtual machines, causing the exported servers not to boot successfully.

Separately, AppAssure has released a new utility called the Recovery Point Verifier. This tool runs against any set of Replay recovery points to detect source disk issues (chkdsk), corruption caused by TxF or issues that may complicate a restoration. See article KB4610014 for more details. Future releases of Replay, starting in release 4.7, will perform nightly checks for Agent-side disk errors with chkdsk.

Affected Platforms

Replay Agent: v4.4, v4.5 and v4.6
Operating System: Vista, Windows 7, Windows 2008 and Windows 2008 R2

Solution for Replay 4.6.x

1. Download and install Replay hotfix from HERE.

NOTE: This update will require a reboot.

2. Force a ReSync operation on your Agent(s) after the update is performed to ensure recovery point integrity.

Optional: Boot CD Builder can be downloaded from HERE, and Replay hotfix release notes from HERE.

NOTE: The Replay Core server is capable of protecting both updated and non-updated Agents, so customers can schedule the update as needed.

Solution for Replay 4.4.x, 4.5.x

1. Download and install Replay hotfix from HERE.

NOTE:This update will require a reboot.

2. Force a ReSync operation on your Agent(s) after the update is performed to ensure recovery point integrity.

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