Mapping sectors to have errors

Mapping sectors to have errors

[Yathindra]

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Hi,

I'm trying to create a disk and map some sectors to have errors on them.

I tried this,
echo "0 100000 linear /dev/sdb 0 100000 480081250 error"| dmsetup create 
bad_disk
device-mapper: reload ioctl failed: Invalid argument
Command failed

I have put in the right arguments but not sure why it fails.

Could someone please guide me how I can do this.

Thanks,
Yathi

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Re: Mapping sectors to have errors

[Joe Thornber]

On Thu, Oct 27, 2011 at 08:31:00PM -0600, Yathindra wrote:
> Hi,
> 
> I'm trying to create a disk and map some sectors to have errors on them.
> 
> I tried this,
> echo "0 100000 linear /dev/sdb 0 100000 480081250 error"| dmsetup
> create bad_disk
> device-mapper: reload ioctl failed: Invalid argument
> Command failed
> 
> I have put in the right arguments but not sure why it fails.

You have 2 target lines concatenated onto the same line there.

Re: Mapping sectors to have errors

[Yathindra]

Hi Joe,

I tried it the other way but when I specify error it doesn't seem to take
the start sector > 0.

# echo "0 `blockdev --getsz /dev/sdb` linear /dev/sdb 0" | dmsetup 
create bad_disk

# dmsetup table
bad_disk: 0 488281250 linear 8:16 0

# echo "100000 488181250 error" | dmsetup load bad_disk << This failed
device-mapper: reload ioctl failed: Invalid argument
Command failed

# echo "0 100000 error" |  dmsetup load bad_disk << This worked

Any ideas?

Thanks,
Yathi


On 10/28/2011 3:11 AM, Joe Thornber wrote:
> On Thu, Oct 27, 2011 at 08:31:00PM -0600, Yathindra wrote:
>> Hi,
>>
>> I'm trying to create a disk and map some sectors to have errors on them.
>>
>> I tried this,
>> echo "0 100000 linear /dev/sdb 0 100000 480081250 error"| dmsetup
>> create bad_disk
>> device-mapper: reload ioctl failed: Invalid argument
>> Command failed
>>
>> I have put in the right arguments but not sure why it fails.
> You have 2 target lines concatenated onto the same line there.

Re: Mapping sectors to have errors

[Milan Broz]

On 10/28/2011 04:31 AM, Yathindra wrote:
> I'm trying to create a disk and map some sectors to have errors on them.
> 
> I tried this,
> echo "0 100000 linear /dev/sdb 0 100000 480081250 error"| dmsetup create bad_disk
> device-mapper: reload ioctl failed: Invalid argument
> Command failed

Try
echo -e "0 100000 linear /dev/sdb 0\n100000 480081250 error"| dmsetup create bad_disk

Milan

Re: Mapping sectors to have errors

[Yathindra]

Hi Milan,

It worked! Thanks so much ! :)

Have a great weekend.

On 10/28/2011 1:42 PM, Milan Broz wrote:
> On 10/28/2011 04:31 AM, Yathindra wrote:
>> I'm trying to create a disk and map some sectors to have errors on them.
>>
>> I tried this,
>> echo "0 100000 linear /dev/sdb 0 100000 480081250 error"| dmsetup create bad_disk
>> device-mapper: reload ioctl failed: Invalid argument
>> Command failed
> Try
> echo -e "0 100000 linear /dev/sdb 0\n100000 480081250 error"| dmsetup create bad_disk
>
> Milan

Re: Mapping sectors to have errors

[Yathindra]

Hi Milan,

I'm trying to inject random sector errors using device mapper.

Suppose I want to inject some 50 errors on random sectors, is their a 
way to do
this without having to reload the table every time.

Thanks,
Yathi

On 10/28/2011 1:46 PM, Yathindra wrote:
> Hi Milan,
>
> It worked! Thanks so much ! :)
>
> Have a great weekend.
>
> On 10/28/2011 1:42 PM, Milan Broz wrote:
>> On 10/28/2011 04:31 AM, Yathindra wrote:
>>> I'm trying to create a disk and map some sectors to have errors on 
>>> them.
>>>
>>> I tried this,
>>> echo "0 100000 linear /dev/sdb 0 100000 480081250 error"| dmsetup 
>>> create bad_disk
>>> device-mapper: reload ioctl failed: Invalid argument
>>> Command failed
>> Try
>> echo -e "0 100000 linear /dev/sdb 0\n100000 480081250 error"| dmsetup 
>> create bad_disk
>>
>> Milan
>