Western Digital White Label Drives In ReadyNAS

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egranuloma wrote:

"The responses I received from Synology, QNAP, NETGEAR and Buffalo all indicated that their NAS RAID controllers don't depend on or even listen to TLER, CCTL, ERC or any other similar error recovery signal from their drives. Instead, their software RAID controllers have their own criteria for drive timeouts, retries and when a drive is finally marked bad."

If this is true, then having drives with TLER in not needed because OS6 handles things its own way, correct?

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This is amost completely wrong.

1. Complete B.S. Syno, QNAP, Netgear (dunno 100% sure for Buffalo) do NOT make use of RAID controllers on thier NAS. Most is typically classic Linux MD device ...

2. There is neither a "listen" nor a TLER/CCTL/ERC signal - if a drive does go into a deep error recovery process - this can take up to several minutes - and the process does exceed about 7 seconds, drives are ejected from a RAID. E

3. Enabling the feature (the designation depends on the HDD maker - it's all thre same) does limit the error recovery time to less than seven seconds.

4. Drives need (much) less spare blocks (or virtual block or sector replacement), because of the deep error recovery is often effective, certainly for a while. Manufaturers want to avoid this, want to take advantege of the deep recovery process, sell thse drives for less - but often don't allow enabling the TLER bit.

5. The drive does not have to be marked bad - it's simply thrown out of the RAID - depending on the redundancy ... figure bye-bye data.

What is the source for the quoted text?