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

On Wed, 5 Jan 2005, Guy wrote:

I agree, but for a different reason.  Your reason is new to me.

..

Loosing the swap disk would kill the system.

if one is using swap space ... i'd add more memory .. before i'd use raid
	- swap is too slow and as you folks point out, it could die
	due to (unlikely) bad disk sectors in swap area

I don't want a down system due to a single disk failure.

that's what raid's for :-)

I mirror everything, or RAID5.  Normally, no downtime due to disk failures.

the problem with mirror ( raid1 ).. or raid5 ...
	- if you have a bad diska ... all "bad data" will/could  also get
	copied to the good disk

	- "bad data" is hard to figure out in code ... to prevent it from
	getting copied ... how does it know with 100% certainty 

	- if you know why it's bad data,  it's lot easier to know which
	data is more correct than the bad one

	- as everybody has pointed out .. bad data ( disk errors )
	can occur for any number of gazillion reasons

have fun raiding
alvin