On Thu, Nov 5, 2015 at 12:05 PM, D. Hugh Redelmeier <[email protected]> wrote: > | From: o1bigtenor <[email protected]> > > | A tip - - - some of the drives marketed as applicable to NAS raid arrays > really > | aren't applicable. You need to be purchasing drives that have ERC or error > | recovery control. I was slapped upside the head because I had drives that > didn't > | have that but when I bought the drives (early 2012) NOBODY was talking about > | that. > > I've heard that some RAID systems do know how to deal with such > drives. I haven't researched which ones. > > Lots of us were talking about this (whining, actually). I usually > called it TLER, Western Digital's term for it. ERC is Seagate's name. > CCTL was used by Samsung and Hitachi. > > Earlier it was possible to tell a drive to limit error recovery time. > Then the drive manufacturers locked this feature out on their cheap > drives. Grrr.
This sounds like a problem looking for a solution -- - - a software hack to fix a hardware problem - - - I know 0 about programming or I would be looking into it already! > > Disks with TLER / ERC / CCTL & LCC [Table of drives] (2011 March) > <http://hardforum.com/showthread.php?t=1590200> > > I posted to this list: > From: D. Hugh Redelmeier <[email protected]> > To: [email protected] > Date: Thu, 28 Jun 2012 21:58:59 -0400 (EDT) > Subject: Re: [TLUG]: 3TB Harddisk sale > > | From: Anthony de Boer <[email protected]> > > | I expect I'll be trying the WD RE4 Lennart mentions next. > > My understanding is that RE and non-RE are the same EXCEPT for "TLER" > (a trivial firmware difference). > > Without TLER, RAID won't work. A drive will spend so much time > recovering from a simple local error that the controller will declare > the whole drive offline. That is a big failure. It generally > requires the array to be rebuilt, possibly taking longer than the > actual MTBF! > > That's how they do "market segmentation". Market segmentation is a > vendor's dream: sell essentially the same product at two different > price points. > > If the drive manufacturing industry were not an oligopoly, this price > differentiation would disappear. In fact, I think Samsung's normal > drives were capable of TLER; that's been fixed by Seagate taking them > over. > --- Very interesting - - - time for some hacker ingenuity!!! Anyone that knows this stuff care to hand out some pointers? Dee --- Talk Mailing List [email protected] http://gtalug.org/mailman/listinfo/talk
