FÓRUM QNAPCLUB.CZ

Important QTS Update for Potential Data Corruption on NAS Using RAID 5/6

Release date: July 25, 2017
Severity: Critical

Scope

The following models are NOT affected:
TS-409, TS-409U, TS-509, TS-809, TS-809 Pro, TS-809U, TS-x10, TS-x10U, HS-210, HS-210-D, HS-210-X, TS-x12, TS-x12E, TS-x12P, TS-x12U, TS-x19P, TS-x19P+, TS-x19PII, TS-x19U, TS-x20, TS-x20D, TS-x20U, TS-x21, TS-x21U, TS-x28, TAS-x28, TS-x30, TS-x31, TS-x39, TS-x39U, TS-x39 Pro, TS-x39 Pro II, TS-x39 Pro II+, TS-239H, SS-x39, TS-x59, TS-x59U, TAS-x68, TS-x69, TS-x69L, TS-x69U, TS-x69 Pro, TS-269H

Summary
A RAID 5 and RAID 6 algorithm issue that was reported by IT expert Wayne Small has been resolved in QTS builds released after April 17, 2017. Silent data corruption might have occurred on NAS devices with affected QTS builds and RAID 5 or RAID 6 configurations. The latest QTS builds already address this issue and users can recover corrupted data by installing a recent build and then enabling RAID scrubbing. However, RAID scrubbing cannot recover corrupted data if the RAID is degraded.

Solution
QNAP recommends installing any of the following QTS builds:
-QTS 4.3.3.0238 Build 20170703
-QTS 4.2.6 Build 20170628 (only for NAS devices that do not support 4.3.x)

After installing the update, you must also enable RAID scrubbing in order to detect and repair silent data corruption. When RAID scrubbing is enabled, QTS automatically verifies all parity blocks and fixes all mismatched parities to ensure data integrity.

Important: Your NAS usage and RAID capacity greatly affects the RAID scrubbing completion time. It may take any time from several hours to several days, depending on how often the NAS is accessed and on the NAS capacity. QNAP recommends minimizing NAS access while RAID scrubbing is in progress.
Please contact QNAP Support at scrubbing_support@qnap.com if you have any further questions.