Need some information about mdadm 3.2.5

Need some information about mdadm 3.2.5

[Tarak Anumolu]

Hi

My name is TARAK.

We got some problem in using mdadm 3.2.5.

We are trying to do RAID operation on 8 harddisks each of size 1TB with 7 harddisks as raid devices and 1 hard disk as spare device.

Command : mdadm -C /dev/md0 -f --meta-version 0.9 -l5 -n7 -x1 /dev/sd[a-h]1

After the RAID operation is completed when we check the status,We are getting the following errors.

 # parted - s  /dev/md0 print
 Model: Linux Software RAID Array (md)
 Disk /dev/md0: 6001GB
 Sector size (logical/physical): 512B/512B
 Partition Table: gpt
 Number Start End Size File system Name Flags
 1 1049kB 60.0GB 60.0GB xfs primary
 2 60.0GB 6001GB 5941GB primary

# parted -s /dev/md0 print 
Error: /dev/md0: unrecognised disk label 

# parted -s /dev/md0 print 
Error: partition length of 23442158592 sectors exceeds the loop-partition-table-imposed maximum of 4294967295 

FYI Our kernel version is Linux mpc8536ds 2.6.32.

Can you please tell me whether there are any compatibility issues with the kernel and whether there is any limitation on raid devices.

When we try with 5 Harddisks, we didn't face any problem.

We are facing this problem when we try to do RAID operation with more than 5 harddisks.

Please help me on this..



Thanks & Regards

Tarak Ramgopal Anumolu 
Security Solution Division
SAMSUNG TECHWIN CO.,LTD
TEL :+82 -70-7147-8396
Mobile: +82-10-7249-8396
E-mail : tarak.anumolu@samsung.com

Re: Need some information about mdadm 3.2.5

[Hans-Peter Jansen]

Hi Tarak,

On Mittwoch, 27. März 2013 05:17:19 Tarak Anumolu wrote:
> Hi
> 
> My name is TARAK.
> 
> We got some problem in using mdadm 3.2.5.
> 
> We are trying to do RAID operation on 8 harddisks each of size 1TB with 7
> harddisks as raid devices and 1 hard disk as spare device.
 
> Command : mdadm -C /dev/md0 -f --meta-version 0.9 -l5 -n7 -x1 /dev/sd[a-h]1

Obviously, you already created partitions on your harddisks.

> After the RAID operation is completed when we check the status,

Beware, the raid creation is a long process, working in background.

To check your md, use: "cat /proc/mdstat". This is the most important command 
in using linux md.

> We are
> getting the following errors.
 
>  # parted - s  /dev/md0 print
>  Model: Linux Software RAID Array (md)
>  Disk /dev/md0: 6001GB
>  Sector size (logical/physical): 512B/512B
>  Partition Table: gpt
>  Number Start End Size File system Name Flags
>  1 1049kB 60.0GB 60.0GB xfs primary
>  2 60.0GB 6001GB 5941GB primary

Now, you want to access the md partition as a harddisk?!?

What you're trying to do makes little sense. Think of the md partition as an 
ordinary one. Partitioning happens *before* md creation (if necessary at all, 
as you can create your mds directly on the harddisks, as long as you need just 
one md, and don't want to boot from it). The *next* logical step here is 
creating a filesystem on the md partition. 

E.g.: mkfs.xfs /dev/md0

Then assign a mount point (in /etc/fstab), and use it. Call back (to this ML), 
when you reached this point, as there are a few more important steps to follow 
for maximum enjoyment.

Cheers,
Pete

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Re: Need some information about mdadm 3.2.5

[Sam Bingner]

On Mar 26, 2013, at 11:28 PM, Hans-Peter Jansen <hpj@urpla.net> wrote:

> Hi Tarak,
> 
> On Mittwoch, 27. März 2013 05:17:19 Tarak Anumolu wrote:
>> Hi
>> 
>> My name is TARAK.
>> 
>> We got some problem in using mdadm 3.2.5.
>> 
>> We are trying to do RAID operation on 8 harddisks each of size 1TB with 7
>> harddisks as raid devices and 1 hard disk as spare device.
> 
>> Command : mdadm -C /dev/md0 -f --meta-version 0.9 -l5 -n7 -x1 /dev/sd[a-h]1
> 
> Obviously, you already created partitions on your harddisks.
> 
>> After the RAID operation is completed when we check the status,
> 
> Beware, the raid creation is a long process, working in background.
> 
> To check your md, use: "cat /proc/mdstat". This is the most important command 
> in using linux md.
> 
>> We are
>> getting the following errors.
> 
>> # parted - s  /dev/md0 print
>> Model: Linux Software RAID Array (md)
>> Disk /dev/md0: 6001GB
>> Sector size (logical/physical): 512B/512B
>> Partition Table: gpt
>> Number Start End Size File system Name Flags
>> 1 1049kB 60.0GB 60.0GB xfs primary
>> 2 60.0GB 6001GB 5941GB primary
> 
> Now, you want to access the md partition as a harddisk?!?
> 
> What you're trying to do makes little sense. Think of the md partition as an 
> ordinary one. Partitioning happens *before* md creation (if necessary at all, 
> as you can create your mds directly on the harddisks, as long as you need just 
> one md, and don't want to boot from it). The *next* logical step here is 
> creating a filesystem on the md partition. 
> 
> E.g.: mkfs.xfs /dev/md0
> 
> Then assign a mount point (in /etc/fstab), and use it. Call back (to this ML), 
> when you reached this point, as there are a few more important steps to follow 
> for maximum enjoyment.
> 
> Cheers,
> Pete
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


I would only add that if you do want to split it into smaller sections, you may be interested in LVM on RAID.  I also wonder why you chose metadata 0.9 as that limits you in the future if you ever wish to use large devices (>2TB or 4TB depending on your kernel)
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Problem with XOR Engine

[Tarak]

Hi

My name is Tarak.

I got some problem with the XOR engine while creating the RAID array.

The parity data is getting corrupted and my system is not able to recognize 
it and some how we are getting the hard disk error.

I found the above issue is happening when I  enable  
CONFIG_RAID_ZERO_COPY=y in my Linux configuration.


Without this option everything is working fine.
 

Following are the version details

Linux : 3.0.34
GCC : 4.6.2 (GCC) ) 
mdadm : v3.2.5 
 

I want to know the way to fix the RAID parity error.

Please help me on this.

Thanks and Regards
Tarak

Re: Need some information about mdadm 3.2.5

[Tarak Anumolu]

Hi

 
My name is Tarak.
 

I got some problem with the XOR engine while creating the RAID array.
 

The parity data is getting corrupted and my system is not able to recognize 
it and some how we are getting the hard disk error.


I found the above issue is happening when I  enable  
CONFIG_RAID_ZERO_COPY=y in my Linux configuration.


Without this option everything is working fine.


Following are the version details

Linux : 3.0.34

GCC : 4.6.2 (GCC) ) 
mdadm : v3.2.5 


 

I want to know the way to fix the RAID parity error.

 
Please help me on this.

 


Thanks & Regards



Tarak Ramgopal Anumolu 

Security Solution Division

SAMSUNG TECHWIN CO.,LTD

Phone : +82-70-7147-8396

Mobile: +82-10-7249-8396

E-mail : tarak.a@samsung.com

Re: Need some information about mdadm 3.2.5

[Tarak Anumolu]

Hi
 
My name is Tarak.

I got some problem with the XOR engine while creating the RAID array.

The parity data is getting corrupted and my system is not able to recognize 
it and some how we are getting the hard disk error.

I found the above issue is happening when I  enable  
CONFIG_RAID_ZERO_COPY=y in my Linux configuration.


Without this option everything is working fine.

Following are the version details

Linux : 3.0.34

GCC : 4.6.2 (GCC) ) 
mdadm : v3.2.5 


I want to know the way to fix the RAID parity error.

Please help me on this.


Thanks & Regards

Tarak Ramgopal Anumolu 

Security Solution Division

SAMSUNG TECHWIN CO.,LTD

Phone : +82-70-7147-8396

Mobile: +82-10-7249-8396

E-mail : tarak.a@samsung.com