TLER, CCLR, and RAID 0

[dcouzin]

RAID 0 has nothing to do with data recovery so this is the wrong forum for my question. That's half my point: advice is given for RAID 0 as if RAID 0 behaved like the other RAID arrays which do accomplish data recovery.

For example, RAID/Enterprise class hard drives typically come with their TLER or CCLR enabled to limit error recovery to 7 seconds. Past 7 seconds let the RAID controller deal with the error recovery. The RAID 0 controller can do no such thing. So what happens when a RAID/Enterprise class drive used in RAID 0 exceeds 7 seconds attempting correction? Is the RAID 0 controller so intelligent to tell the drive to get back to the error correction, and the drive so intelligent to obey? If not, and if TLER or CCLR can't be disabled, it would seem that using RAID/Enterprise class hard drives is a bad idea, error correction wise, in RAID 0. Is this reasoning correct?

It would be especially nice to have the extra durability of RAID/Enterprise class drives for RAID 0 because RAID 0 arrays have no redundancy. But can the TLER or CCLR be disabled? In particular, can the 7 second CCLR setting on the Samsung HE103UJ be disabled? (I'm using a Mac. HDAT2 isn't a practical solution for me.)

Thanks.

[Amarbir[CDR-Labs]]

RAID 0 has nothing to do with data recovery so this is the wrong forum for my question. That's half my point: advice is given for RAID 0 as if RAID 0 behaved like the other RAID arrays which do accomplish data recovery.

For example, RAID/Enterprise class hard drives typically come with their TLER or CCLR enabled to limit error recovery to 7 seconds. Past 7 seconds let the RAID controller deal with the error recovery. The RAID 0 controller can do no such thing. So what happens when a RAID/Enterprise class drive used in RAID 0 exceeds 7 seconds attempting correction? Is the RAID 0 controller so intelligent to tell the drive to get back to the error correction, and the drive so intelligent to obey? If not, and if TLER or CCLR can't be disabled, it would seem that using RAID/Enterprise class hard drives is a bad idea, error correction wise, in RAID 0. Is this reasoning correct?

It would be especially nice to have the extra durability of RAID/Enterprise class drives for RAID 0 because RAID 0 arrays have no redundancy. But can the TLER or CCLR be disabled? In particular, can the 7 second CCLR setting on the Samsung HE103UJ be disabled? (I'm using a Mac. HDAT2 isn't a practical solution for me.)

Thanks.

Well ,
You Are Taking About Features of RAID .But Asking About HDD Drives Basic Versus Enterprise .Enterprise Drives Are Far Better in everything then basic drives ,Be it component selection in factory to mtbf etc .

[qubit]

It would be wonderful if TLER were taken a step further, with a protocol allowing the host (in this case, a RAID controller) to tell the hard drive controller how heavily to indulge in error recovery. However, AFAIK, TLER has only been implemented as an on/off flag. Some RAID controllers may be more intelligent than others in dealing with the fact that hard drives may vary in how much time they will persist in recovering a sector; I wish I knew.

Enabling and disabling TLER is a vendor-specific operation. I only know of WDTLER.EXE, because the newer drives I've purchased are all Western Digitals, however the utility is far from convenient to use. WD stopped distributing it, and not all of their drives support it. I haven't gotten around to attempting to enable TLER on my eight WD15EADS which I keep in a RAID 5 array. The RAID controller I use has a very poor JBOD mode which does not allow raw ATA, so I'd have to plug the drives into my motherboard's SATA slots in rotation, through the course of multiple reboots into plain DOS.

[dcouzin]

... Enterprise Drives Are Far Better in everything then basic drives ,Be it component selection in factory to mtbf etc .

Amarbir, if an Enterprise class drive comes with a 7 second TLER setting and if there is no way to change this setting, then is this drive as good in regard to error correction as a Desktop class drive for use in a RAID 0 array?

I think not. So I'm not jumping to use Samsung HE103UJ's in preference to Samsung HD103UJ's in a RAID 0 array until someone explains how I can set the CCLR on the former to (practically) unlimited time.

Thanks.