bad HD sectors
jd1008 at gmail.com
Sun Jun 20 13:41:13 UTC 2010
On 06/20/2010 06:29 AM, Dave Ihnat was caught red-handed while writing::
> On Sun, Jun 20, 2010 at 12:00:59AM -0700, JD wrote:
>> So, it is not clear that fsck will detect new
>> bad blocks.
> Man 'badblocks'. Note, from the manpage:
> "...it is strongly recommended that users not run badblocks directly,
> but rather use the -c option of the e2fsck and mke2fs programs."
>> I read about the old days when the drives did not do auto bad block
>> forwarding (re-mapping).
> I lived through "the old days". (Funny....they don't seem that far
> back...) I still have a full-sized 5.25" drive in the basement...acting
> as a doorstop.
>> There was a low level formatter which actually detected the bad blocks
>> and remapped them. Unfortunately for today, once the drive runs out of
>> spare good blocks to forward bad blocks to, throw it away. I really
>> wish there was such a low level formatter for today's drives. It would
>> extend the life of a drive a little longer.
> No, you don't. Having blocks spontaneously go bad, and having to scan
> the system for them, was a Bad Thing(Tm). It took a lot of time--and
> drives were far smaller than today. If you didn't catch 'em--and scans
> were skipped often, because of the time required--you could suffer
> unrecognized damage for a long time.
> At least, with internal drive intelligence, and S.M.A.R.T. (SMART)
> reporting, you can run quitely and with a fair degree of comfort in the
> probability that everything is being properly stored, with bad blocks
> being detected and remapped without constant scanning on your part.
> The fact that so many people, with operating systems of all kinds,
> *don't* turn on SMART monitoring and can run for years without failure
> says it is successful.
> The concomitant flip side is that when you finally *do* start seeing
> SMART errors, you know that so many sectors have failed that it's filled
> the reserve. This is cumulative--by the time this happens, there' no
> real advantage in trying to 'low-level format'; it may never complete,
> but even if it does, you've no confidence that it's going to remain in
> service. SOMETHING was failing--either the controller electronics, or
> the drive's recording surface. It's time to replace it.
> The bad news is that customers have rewarded drive vendors not for "fast,
> big, and reliable", but "fast, big, and cheap". Drives generally fail
> more often than you'd want. The good news is that "cheap" part--drives
> that are stupidly big can be found for pennies on the gigabyte. 1TB
> SATA for $64 (shopper.cnet.com).
> Hell, I remember in the early '80s--I was on contract at Bell
> Telephone Laboratories in Naperville, IL. They had a **huge**
> celebration--commemorative coffee mugs and other chachkes, cake and
> coffee, at a big outdoor ceremony. What was the occasion?
> The data storage for the entire data center had just crossed the magic 1
> Terabyte limit...
> Dave Ihnat
> dihnat at dminet.com
Well, I'm hoping that WD will send me a replacement.
It's still under 3 years of age.
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