errors Re: ext3 journal on software raid (was Re: PROBLEM: Kernel 2.6.10 crashing repeatedly and hard)

hi ya michael

On Wed, 5 Jan 2005, Michael Tokarev wrote:

The drive IS reporting read errors in most cases.

and by the time it reports an error ... its too late ...

- one has to play detective and figure out why the error occured
  and prevent it next time

- the worst possible thing to do is .. "disk seems to be dying"
  so 95% of the people say backup the disks ..
	-- its too too late
	-- exercising a dead/dying disks will only aggravate the
	problem even more

- luckily, most "disks errors" are silly errors
	- bad (cheap, not-too-specs) ide cables
	- 80 conductor vs 40 conductor
	- combining 2 different ata speed drives on the same idea cable
	- too long of an ide cable ... 18" is max
	- disk running too hot ... if its warm to the touch,
	its too hot
	( 35C is maybe okay .. use hddtemp to see what its running at )
	- bent disk cables 
	- bad (electrical characteristics) of the ide drivers from the
	motherboard
	- ... on and on ...

	- todays drives are 1000x better quality than 5-10 years ago

so things are screwed.  Just like if you hot-remove a DIMM while the
system is running:

those that do hot-swap of memory deserve what they get :-)
( i know you're joking ... and i've seen it done by forgetful admins
	- these atx power supplies are bad for that reason, since
	the motherboard is still live, even if the pc is off, due to
	standby voltages floating around

 The talks isn't about
"undetectable" (unreported etc) errors here, but about the fact that
the error is here.

the trick is to find out what caused the error ... 
	- if you dont figure out what happened ... the problem will 
	continue 

have fun raiding
alvin