7Tb XFS partition lost on reboot

7Tb XFS partition lost on reboot

[Amandine AUPETIT]

Hi !
(I'm on Ubuntu 7.10 64 bits)
I have array of 12 750gb disks in hardware Raid 6 that gives me a 7Tb 
partition. I tried to format it in ext3, but it took too much time, so I 
tried in Reiserfs, but the partition were lost on reboot, and now i'm 
trying XFS.

So I created the partition with parted, because fdisk can't do more that 
2tb partitions.
It's ok, I can do what I want but...

on reboot, there is a Superblock problem, something like that. When I 
check with xfs_check :

xfs_check: unexpected XFS SB magic number 0x00000000
xfs_check: read failed: Invalid argument
xfs_check: data size check failed
cache_node_purge: refcount was 1, not zero (node=0x681420)
xfs_check: cannot read root inode (22)
bad superblock magic number 0, giving up

So, I tried to delete the partition with parted, to recreate a new one. 
No problem. But when I mount the new partition, all the data that were 
on my deleted partition are there !!! That's of course not a problem, 
but I'm wondering if there's a way to have this partition work directly 
without having to delete and recreate it ?

I checked the /proc/partition before and after doing parted :

BEFORE
major minor  #blocks  name
 104     0   35532720 cciss/c0d0
 104     1   34025638 cciss/c0d0p1
 104     2          1 cciss/c0d0p2
 104     5    1502046 cciss/c0d0p5
 105     0 7325417080 cciss/c1d0
 105     1  [B]882966102[/B] cciss/c1d0p1

AFTER
major minor  #blocks  name
 104     0   35532720 cciss/c0d0
 104     1   34025638 cciss/c0d0p1
 104     2          1 cciss/c0d0p2
 104     5    1502046 cciss/c0d0p5
 105     0 7325417080 cciss/c1d0
 105     1 [B]7325417046[/B] cciss/c1d0p1


So, any idea what I could do ?

Thanks a lot
Amandine

Re: 7Tb XFS partition lost on reboot

[Joshua Baker-LePain]

On Tue, 6 Nov 2007 at 2:58pm, Amandine AUPETIT wrote

> So I created the partition with parted, because fdisk can't do more that 2tb 
> partitions.
> It's ok, I can do what I want but...
>
> on reboot, there is a Superblock problem, something like that. When I check 
> with xfs_check :

First guess -- did you use a gpt disklabel on that device?  Standard 
(msdos) disklabels don't work on devices >2TB.  The usual symptom of a big 
device with an msdos disklabel is that the partition table goes away on 
reboot.

-- 
Joshua Baker-LePain
QB3 Shared Cluster Sysadmin
UCSF

Re: 7Tb XFS partition lost on reboot

[Eric Sandeen]

Joshua Baker-LePain wrote:
> On Tue, 6 Nov 2007 at 2:58pm, Amandine AUPETIT wrote
> 
>> So I created the partition with parted, because fdisk can't do more that 2tb 
>> partitions.
>> It's ok, I can do what I want but...
>>
>> on reboot, there is a Superblock problem, something like that. When I check 
>> with xfs_check :
> 
> First guess -- did you use a gpt disklabel on that device?  Standard 
> (msdos) disklabels don't work on devices >2TB.  The usual symptom of a big 
> device with an msdos disklabel is that the partition table goes away on 
> reboot.

I second that hunch.  :)

-Eric

Re: 7Tb XFS partition lost on reboot

[Amandine AUPETIT]

Hi,
Thanks for the advice !
I checked the label with xfs_admin -l :
# xfs_admin -l /dev/cciss/c1d0p1
label = ""

I tried to blank it in case there is something invisible :
# xfs_admin -L -- /dev/cciss/c1d0p1
writing all SBs
new label = ""

But it seems to be the same. :(

Amandine


Eric Sandeen a écrit :
> Joshua Baker-LePain wrote:
>   
>> On Tue, 6 Nov 2007 at 2:58pm, Amandine AUPETIT wrote
>>
>>     
>>> So I created the partition with parted, because fdisk can't do more that 2tb 
>>> partitions.
>>> It's ok, I can do what I want but...
>>>
>>> on reboot, there is a Superblock problem, something like that. When I check 
>>> with xfs_check :
>>>       
>> First guess -- did you use a gpt disklabel on that device?  Standard 
>> (msdos) disklabels don't work on devices >2TB.  The usual symptom of a big 
>> device with an msdos disklabel is that the partition table goes away on 
>> reboot.
>>     
>
> I second that hunch.  :)
>
> -Eric
>   

Re: 7Tb XFS partition lost on reboot

[Eric Sandeen]

Amandine AUPETIT wrote:
> Hi,
> Thanks for the advice !
> I checked the label with xfs_admin -l :
> # xfs_admin -l /dev/cciss/c1d0p1
> label = ""
> 
> I tried to blank it in case there is something invisible :
> # xfs_admin -L -- /dev/cciss/c1d0p1
> writing all SBs
> new label = ""
> 
> But it seems to be the same. :(

No, not the filesystem label, the disklabel, otherwise known as the
partition table - dos vs. gpt.  This is something you set with parted or
fdisk, not xfs_admin.

-Eric

Re: 7Tb XFS partition lost on reboot

[Amandine AUPETIT]

Ok, sorry for the mix-up.
You were right, the problem was about the partition table.
Actually, even if it was a gpt partition table, it was corrupted. I 
seems to be a ubuntu parted problem. I had to rebuild pared from the 
sources and when I ran it, it said :

# ./parted
GNU Parted 1.8.8
Using /dev/cciss/c1d0
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print                                                           
print
Warning: /dev/cciss/c1d0 contains GPT signatures, indicating that it has 
a GPT
table.  However, it does not have a valid fake msdos partition table, as it
should.  Perhaps it was corrupted -- possibly by a program that doesn't
understand GPT partition tables.  Or perhaps you deleted the GPT table, 
and are
now using an msdos partition table.  Is this a GPT partition table?
Yes/No? yes                                                              
yes
Model: Compaq Smart Array (cpqarray)
Disk /dev/cciss/c1d0: 7501GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system  Name     Flags
 1      17.4kB  7501GB  7501GB  xfs          primary      



So I deleted the existing partition and recreated a new one. I found 
back all my data on this new partition, and on reboot there is no 
problem anymore.

Thanks a lot for your help ! :)

Amandine


Eric Sandeen a écrit :
> Amandine AUPETIT wrote:
>   
>> Hi,
>> Thanks for the advice !
>> I checked the label with xfs_admin -l :
>> # xfs_admin -l /dev/cciss/c1d0p1
>> label = ""
>>
>> I tried to blank it in case there is something invisible :
>> # xfs_admin -L -- /dev/cciss/c1d0p1
>> writing all SBs
>> new label = ""
>>
>> But it seems to be the same. :(
>>     
>
> No, not the filesystem label, the disklabel, otherwise known as the
> partition table - dos vs. gpt.  This is something you set with parted or
> fdisk, not xfs_admin.
>
> -Eric
>   

Re: 7Tb XFS partition lost on reboot

[Eric Sandeen]

Amandine AUPETIT wrote:

> So I deleted the existing partition and recreated a new one. I found 
> back all my data on this new partition, and on reboot there is no 
> problem anymore.


Wow, I love a happy ending, especially when it involves 7T of data ;-)

-Eric