Re: ll_ver_fs data verification failure - 96TB fs

[Valerie Aurora <vaurora@redhat.com>]

On Mon, Aug 03, 2009 at 09:54:36AM -0400, Nick Dokos wrote:
> Just a heads-up for now. I ran ll_ver_fs on a 96TB fs - the write phase
> finished without problems, but the read phase encountered a problem:
> 
> ...
> read File name: /mnt/dir00373/file026
> 
> liverfs: verify /mnt/dir00373/file026 failed offset/timestamp/inode 3244298240/1248819541/1096796: found 3243249664/1248819541/1096796 instead
> 
> liverfs: Data verification failed
> 770.45user 218639.65system 67:38:18elapsed 90%CPU (0avgtext+0avgdata 0maxresident)k
> 100357573552inputs+195522668184outputs (1major+414minor)pagefaults 0swaps
> make: *** [llver] Error 2
> 
> 
> The offset difference is exactly 1M, and it occurs about 3GB into the file.

Interesting - exactly 1M off.  Does this correspond to anything
interesting in extent layout or block allocation boundaries?

Any chance you can patch ll_ver_fs to continue after the first error?
I'd be happy to write the patch for you.

> In total, there are 726 directories, each with 32 4GB files (except the last,
> which only has 12 files). So directory 373 is roughly half-way. I'll take a look
> at the block allocation of both the directory and the file and see if they are
> straddling the 16TB boundary (or other such).

Did you have a chance to look at what falls before and after the 16TB
boundary?

Thanks,

-VAL