List of corruption cases for scrub

List of corruption cases for scrub

[Lakshmipathi.G]

Hi.

I tried to a create list of corruption test scenarios for scrubbing process with RAID5.
Here's the list: https://btrfs.wiki.kernel.org/index.php/Scrub_corruption_cases

If similar list already exists in btrfs wiki, let me know, I'll move this data
to there. Feel free to add/update/delete entries or suggest new corrupt ideas!

Cheers.
Lakshmipathi.G

Re: List of corruption cases for scrub

[Goffredo Baroncelli]

Hi,
On 2017-02-24 03:32, Lakshmipathi.G wrote:
> Hi.
> 
> I tried to a create list of corruption test scenarios for scrubbing process with RAID5.
> Here's the list: https://btrfs.wiki.kernel.org/index.php/Scrub_corruption_cases
> 
> If similar list already exists in btrfs wiki, let me know, I'll move this data
> to there. Feel free to add/update/delete entries or suggest new corrupt ideas!

Thanks for doing that. About the test "Device-corruption", I suppose that you want to test a scenario where one disk fails. If so you do not have to always corrupt "D0" block, but the first block of the file which is stored in the failing disk (which could be different from the D0).

Another scenario which should be tested, is the reshaping of the raid: add a drive (or remove a drive) then re-balance the system (with or without some corruption). IIRC this use the same scrub code.

> 
> Cheers.
> Lakshmipathi.G
> --


BR
G.Baroncelli


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Re: List of corruption cases for scrub

[Lakshmipathi.G]

On Fri, Feb 24, 2017 at 06:39:20PM +0100, Goffredo Baroncelli wrote:
> Hi,
> On 2017-02-24 03:32, Lakshmipathi.G wrote:
> > Hi.
> > 
> > I tried to a create list of corruption test scenarios for scrubbing process with RAID5.
> > Here's the list: https://btrfs.wiki.kernel.org/index.php/Scrub_corruption_cases
> > 
> > If similar list already exists in btrfs wiki, let me know, I'll move this data
> > to there. Feel free to add/update/delete entries or suggest new corrupt ideas!
> 
> Thanks for doing that. About the test "Device-corruption", I suppose that you want to test a scenario where one disk fails. If so you do not have to always corrupt "D0" block, but the first block of the file which is stored in the failing disk (which could be different from the D0).
> 
Yes, that's right. Updated (Device-corruption) the list now.

> Another scenario which should be tested, is the reshaping of the raid: add a drive (or remove a drive) then re-balance the system (with or without some corruption). IIRC this use the same scrub code.
> 
Added this as 'Rebalance-corruption' on the wiki. thanks!

Cheers.
Lakshmipathi.G

Re: List of corruption cases for scrub

[Lakshmipathi.G]

On Mon, Feb 27, 2017 at 11:40:31AM +0800, Qu Wenruo wrote:
> 
> 
> At 02/24/2017 10:32 AM, Lakshmipathi.G wrote:
> >Hi.
> >
> >I tried to a create list of corruption test scenarios for scrubbing process with RAID5.
> >Here's the list: https://btrfs.wiki.kernel.org/index.php/Scrub_corruption_cases
> >
> >If similar list already exists in btrfs wiki, let me know, I'll move this data
> >to there. Feel free to add/update/delete entries or suggest new corrupt ideas!
> 
> What about adding testing result for latest kernel release?
> 
> Thanks,
> Qu

True, Ideally, the wiki should have list-corruption cases along with result for
each latest kernel version.

Planning to add more cases, gradually. For example, I think inode object
with RAID5 can be replicated across drives. If thats correct, can scrub 
fix those corruption too? cases like this may be more important than other
to-do items like raid5 with features like snapshot/quota etc

I think it should be possible to add test-results for few cases but list has
repeated-cases with different sizes,drives etc for these cases we need some
kind of automated scripts.

Hope to extend the cases first and then start updating results with manual or 
automated tests.

Cheers.
Lakshmipathi.G