Creating RAID1 with bitmap fails

Creating RAID1 with bitmap fails

[Jan Engelhardt]

Hi,


the following command strangely gives -EIO ...
12:27 sun:~ # mdadm -C /dev/md4 -l 1 -n 2 -e 1.0 -b internal /dev/ram0 
missing

md: md4: raid array is not clean -- starting background reconstruction
md4: failed to create bitmap (-5)
md: pers->run() failed ...
mdadm: RUN_ARRAY failed: Input/output error
mdadm: stopped /dev/md4

Leaving out -b internal creates the array. /dev/ram0 or /dev/sda5 - EIO 
happens on both. (But the disk is fine, like ram0)
Where could I start looking?

Linux sun 2.6.21-1.3149.al3.8smp #3 SMP Wed May 30 09:43:00 CEST 2007 
sparc64 sparc64 sparc64 GNU/Linux
mdadm 2.5.4


Thanks,
	Jan
-- 

Re: Creating RAID1 with bitmap fails

[Neil Brown]

On Wednesday May 30, jengelh@linux01.gwdg.de wrote:
> Hi,
> 
> 
> the following command strangely gives -EIO ...
> 12:27 sun:~ # mdadm -C /dev/md4 -l 1 -n 2 -e 1.0 -b internal /dev/ram0 
> missing
> 
> md: md4: raid array is not clean -- starting background reconstruction
> md4: failed to create bitmap (-5)
> md: pers->run() failed ...
> mdadm: RUN_ARRAY failed: Input/output error
> mdadm: stopped /dev/md4
> 
> Leaving out -b internal creates the array. /dev/ram0 or /dev/sda5 - EIO 
> happens on both. (But the disk is fine, like ram0)
> Where could I start looking?
> 
> Linux sun 2.6.21-1.3149.al3.8smp #3 SMP Wed May 30 09:43:00 CEST 2007 
> sparc64 sparc64 sparc64 GNU/Linux
> mdadm 2.5.4

I'm fairly sure this is fixed in 2.6.2.  It is certainly worth a try.

NeilBrown

Re: Creating RAID1 with bitmap fails

[Jan Engelhardt]

On May 30 2007 22:05, Neil Brown wrote:
>> 
>> the following command strangely gives -EIO ...
>> 12:27 sun:~ # mdadm -C /dev/md4 -l 1 -n 2 -e 1.0 -b internal /dev/ram0 
>> missing
>> 
>> md: md4: raid array is not clean -- starting background reconstruction
>> md4: failed to create bitmap (-5)
>> md: pers->run() failed ...
>> mdadm: RUN_ARRAY failed: Input/output error
>> mdadm: stopped /dev/md4
>> 
>> Leaving out -b internal creates the array. /dev/ram0 or /dev/sda5 - EIO 
>> happens on both. (But the disk is fine, like ram0)
>> Where could I start looking?
>> 
>> Linux sun 2.6.21-1.3149.al3.8smp #3 SMP Wed May 30 09:43:00 CEST 2007 
>> sparc64 sparc64 sparc64 GNU/Linux
>> mdadm 2.5.4
>
>I'm fairly sure this is fixed in 2.6.2.  It is certainly worth a try.

The same command works on a x86_64 with mdadm 2.5.3...


	Jan
-- 

Re: Creating RAID1 with bitmap fails

[Neil Brown]

On Wednesday May 30, jengelh@linux01.gwdg.de wrote:
> 
> On May 30 2007 22:05, Neil Brown wrote:
> >> 
> >> the following command strangely gives -EIO ...
> >> 12:27 sun:~ # mdadm -C /dev/md4 -l 1 -n 2 -e 1.0 -b internal /dev/ram0 
> >> missing
> >> 
> >> md: md4: raid array is not clean -- starting background reconstruction
> >> md4: failed to create bitmap (-5)
> >> md: pers->run() failed ...
> >> mdadm: RUN_ARRAY failed: Input/output error
> >> mdadm: stopped /dev/md4
> >> 
> >> Leaving out -b internal creates the array. /dev/ram0 or /dev/sda5 - EIO 
> >> happens on both. (But the disk is fine, like ram0)
> >> Where could I start looking?
> >> 
> >> Linux sun 2.6.21-1.3149.al3.8smp #3 SMP Wed May 30 09:43:00 CEST 2007 
> >> sparc64 sparc64 sparc64 GNU/Linux
> >> mdadm 2.5.4
> >
> >I'm fairly sure this is fixed in 2.6.2.  It is certainly worth a try.
> 
> The same command works on a x86_64 with mdadm 2.5.3...

Are you sure?
I suspect that the difference is more in the kernel version.
mdadm used to create some arrays with the bitmap positioned so that it
overlapped the data.  Recent kernels check for that and reject the
array if there is an overlap.  mdadm-2.6.2 makes sure not to create
any overlap.

NeilBrown

Re: Creating RAID1 with bitmap fails

[Jan Engelhardt]

On May 31 2007 09:09, Neil Brown wrote:
>> >> the following command strangely gives -EIO ...
>> >> 12:27 sun:~ # mdadm -C /dev/md4 -l 1 -n 2 -e 1.0 -b internal /dev/ram0 
>> >> missing
>> >> Where could I start looking?
>> >> 
>> >> Linux sun 2.6.21-1.3149.al3.8smp #3 SMP Wed May 30 09:43:00 CEST 2007 
>> >> sparc64 sparc64 sparc64 GNU/Linux
>> >> mdadm 2.5.4
>> >
>> >I'm fairly sure this is fixed in 2.6.2.  It is certainly worth a try.
>> 
>> The same command works on a x86_64 with mdadm 2.5.3...
  [ with 2.6.18.8 ]

>Are you sure?
>I suspect that the difference is more in the kernel version.
>mdadm used to create some arrays with the bitmap positioned so that it
>overlapped the data.  Recent kernels check for that and reject the
>array if there is an overlap.  mdadm-2.6.2 makes sure not to create
>any overlap.

Regarding above x86_64/2.5.3/2.6.18.8 created array, is there a way to
check whether it overlaps?


	Jan
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