Re: Corrupt btrfs filesystem recovery... (Due to *sata* errors)

[Martin <m_btrfs@ml1.co.uk>]

Chris,

Thanks for good comment/discussion.

On 29/09/13 03:06, Chris Murphy wrote:
> 
> On Sep 28, 2013, at 4:51 PM, Martin <m_btrfs@ml1.co.uk> wrote:
> 

> Stick with forced 3Gbps, but I think it's worth while to find out
> what the actual problem is. One day you forget about this 3Gbps SATA
> link, upgrade or regress to another kernel and you don't have the
> 3Gbps forced speed on the parameter line, and poof - you've got more
> problems again. The hardware shouldn't negotiate a 6Gbps link and
> then do a backwards swan dive at 30,000' with your data as if it's an
> after thought.

I've got an engineer's curiosity so that one is very definitely marked
for revisiting at some time... If only to blog that x-y-z combination is
a tar pit for your data...


>> In any case, for the existing HDD - motherboard combination, using
>> sata2 rather than sata3 speeds shouldn't noticeably impact
>> performance. (Other than sata2 works reliably and so is infinitely
>> better for this case!)
> 
> It's true.

Well, the IO data rate for badblocks is exactly the same as before,
limited by the speed of the physical rust spinning and data density...


> I would also separately unmount the file system, note the latest
> kernel message, then mount the file system and see if there are any
> kernel messages that might indicate recognition of problems with the
> fs.
> 
> I would not use btrfsck --repair until someone says it's a good idea.
> That person would not be me.

It is sat unmounted until some informed opinion is gained...


Thanks again for your notes,

Regards,
Martin