Btrfs - Unable to mount, can't read superblock?

Btrfs - Unable to mount, can't read superblock?

[Victor Hooi]

heya,

This is on kernel 2.6.32.8-1, on Arch Linux 64-bit. I have an external
harddisk, with a btrfs filessystem on it. Just now, after a reboot, I
seem to be unable to mount it.

KDE gives a message about being unable to find the superblock, trying
to mount it from the command-line gives something similar:

> mount: /dev/sdc1: can't read superblock

I do know the last time I used the disk, it may not have been
unmounted cleanly. Could that have caused this current issue? Any
possible remedy? I'm really hoping it is, because that's a 1.5 Tb
external disk...lol.

Also, dmesg contains:
>
> usb 2-2: new high speed USB device using ehci_hcd and address 8
> usb 2-2: configuration #1 chosen from 1 choice
> scsi10 : SCSI emulation for USB Mass Storage devices
> usb-storage: device found at 8
> usb-storage: waiting for device to settle before scanning
> scsi 10:0:0:0: Direct-Access=A0=A0=A0=A0 WDC WD15 EADS-00P8B0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0 PQ: 0 ANSI: 2
> sd 10:0:0:0: Attached scsi generic sg2 type 0
> usb-storage: device scan complete
> sd 10:0:0:0: [sdc] 2930277168 512-byte logical blocks: (1.50 TB/1.36 =
TiB)
> sd 10:0:0:0: [sdc] Write Protect is off
> sd 10:0:0:0: [sdc] Mode Sense: 38 00 00 00
> sd 10:0:0:0: [sdc] Assuming drive cache: write through
> sd 10:0:0:0: [sdc] Assuming drive cache: write through
> =A0sdc: sdc1
> sd 10:0:0:0: [sdc] Assuming drive cache: write through
> sd 10:0:0:0: [sdc] Attached SCSI disk
> device label tessier-ashpool devid 1 transid 4882 /dev/sdc1
> open /dev/sdd1 failed

Cheers,
Victor
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Re: Btrfs - Unable to mount, can't read superblock?

[TARUISI Hiroaki]

Hi,

This disk was used as /dev/sdd previously, and now it's named
/dev/sdc, isn't it?
If so, you can use this usb disk after reboot, or adjusting
that the disk is recognized as /dev/sdd.
Btrfs does not support device file renaming yet.


Regards,
taruisi

(2010/02/13 21:45), Victor Hooi wrote:
> heya,
> 
> This is on kernel 2.6.32.8-1, on Arch Linux 64-bit. I have an external
> harddisk, with a btrfs filessystem on it. Just now, after a reboot, I
> seem to be unable to mount it.
> 
> KDE gives a message about being unable to find the superblock, trying
> to mount it from the command-line gives something similar:
> 
>> mount: /dev/sdc1: can't read superblock
> 
> I do know the last time I used the disk, it may not have been
> unmounted cleanly. Could that have caused this current issue? Any
> possible remedy? I'm really hoping it is, because that's a 1.5 Tb
> external disk...lol.
> 
> Also, dmesg contains:
>>
>> usb 2-2: new high speed USB device using ehci_hcd and address 8
>> usb 2-2: configuration #1 chosen from 1 choice
>> scsi10 : SCSI emulation for USB Mass Storage devices
>> usb-storage: device found at 8
>> usb-storage: waiting for device to settle before scanning
>> scsi 10:0:0:0: Direct-Access     WDC WD15 EADS-00P8B0           PQ: 0 ANSI: 2
>> sd 10:0:0:0: Attached scsi generic sg2 type 0
>> usb-storage: device scan complete
>> sd 10:0:0:0: [sdc] 2930277168 512-byte logical blocks: (1.50 TB/1.36 TiB)
>> sd 10:0:0:0: [sdc] Write Protect is off
>> sd 10:0:0:0: [sdc] Mode Sense: 38 00 00 00
>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>  sdc: sdc1
>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>> sd 10:0:0:0: [sdc] Attached SCSI disk
>> device label tessier-ashpool devid 1 transid 4882 /dev/sdc1
>> open /dev/sdd1 failed
> 
> Cheers,
> Victor
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Btrfs - Unable to mount, can't read superblock?

[Victor Hooi]

Taruisi,

Thanks for that.

I can't believe it was something as simple as that.

It's a laptop, so normally I suspend, But yeah, I've tried rebooting
since (actually before your message - but thanks anyway), and it's all
good now. Seriously gave me a bit of a shock there. Yes, I know, btrfs
isn't stable, but I nearly thought it all went like that, poof *touch
wood* =3D). I guess I wasn't used to it not re-mounting after that afte=
r
an unplug event.

Do you know if there's a timeline for device file renaming? I suppose
it's not that big a deal now that I'm aware it's not supported.

Thanks again for your advice.

Cheers,
Victor

On 15 February 2010 11:28, TARUISI Hiroaki
<taruishi.hiroak@jp.fujitsu.com> wrote:
> Hi,
>
> This disk was used as /dev/sdd previously, and now it's named
> /dev/sdc, isn't it?
> If so, you can use this usb disk after reboot, or adjusting
> that the disk is recognized as /dev/sdd.
> Btrfs does not support device file renaming yet.
>
>
> Regards,
> taruisi
>
> (2010/02/13 21:45), Victor Hooi wrote:
>> heya,
>>
>> This is on kernel 2.6.32.8-1, on Arch Linux 64-bit. I have an extern=
al
>> harddisk, with a btrfs filessystem on it. Just now, after a reboot, =
I
>> seem to be unable to mount it.
>>
>> KDE gives a message about being unable to find the superblock, tryin=
g
>> to mount it from the command-line gives something similar:
>>
>>> mount: /dev/sdc1: can't read superblock
>>
>> I do know the last time I used the disk, it may not have been
>> unmounted cleanly. Could that have caused this current issue? Any
>> possible remedy? I'm really hoping it is, because that's a 1.5 Tb
>> external disk...lol.
>>
>> Also, dmesg contains:
>>>
>>> usb 2-2: new high speed USB device using ehci_hcd and address 8
>>> usb 2-2: configuration #1 chosen from 1 choice
>>> scsi10 : SCSI emulation for USB Mass Storage devices
>>> usb-storage: device found at 8
>>> usb-storage: waiting for device to settle before scanning
>>> scsi 10:0:0:0: Direct-Access =A0 =A0 WDC WD15 EADS-00P8B0 =A0 =A0 =A0=
 =A0 =A0 PQ: 0 ANSI: 2
>>> sd 10:0:0:0: Attached scsi generic sg2 type 0
>>> usb-storage: device scan complete
>>> sd 10:0:0:0: [sdc] 2930277168 512-byte logical blocks: (1.50 TB/1.3=
6 TiB)
>>> sd 10:0:0:0: [sdc] Write Protect is off
>>> sd 10:0:0:0: [sdc] Mode Sense: 38 00 00 00
>>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>> =A0sdc: sdc1
>>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>> sd 10:0:0:0: [sdc] Attached SCSI disk
>>> device label tessier-ashpool devid 1 transid 4882 /dev/sdc1
>>> open /dev/sdd1 failed
>>
>> Cheers,
>> Victor
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-btrf=
s" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at =A0http://vger.kernel.org/majordomo-info.html
>
>
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Re: Btrfs - Unable to mount, can't read superblock?

[TARUISI Hiroaki]

That's good for you. :)

It may be surprising that simple suspending causes disk error.
I posted a simple patch jast a week ago, I hope it will be
merged soon.

Regards,
taruisi

(2010/02/15 18:57), Victor Hooi wrote:
> Taruisi,
> 
> Thanks for that.
> 
> I can't believe it was something as simple as that.
> 
> It's a laptop, so normally I suspend, But yeah, I've tried rebooting
> since (actually before your message - but thanks anyway), and it's all
> good now. Seriously gave me a bit of a shock there. Yes, I know, btrfs
> isn't stable, but I nearly thought it all went like that, poof *touch
> wood* =). I guess I wasn't used to it not re-mounting after that after
> an unplug event.
> 
> Do you know if there's a timeline for device file renaming? I suppose
> it's not that big a deal now that I'm aware it's not supported.
> 
> Thanks again for your advice.
> 
> Cheers,
> Victor
> 
> On 15 February 2010 11:28, TARUISI Hiroaki
> <taruishi.hiroak@jp.fujitsu.com> wrote:
>> Hi,
>>
>> This disk was used as /dev/sdd previously, and now it's named
>> /dev/sdc, isn't it?
>> If so, you can use this usb disk after reboot, or adjusting
>> that the disk is recognized as /dev/sdd.
>> Btrfs does not support device file renaming yet.
>>
>>
>> Regards,
>> taruisi
>>
>> (2010/02/13 21:45), Victor Hooi wrote:
>>> heya,
>>>
>>> This is on kernel 2.6.32.8-1, on Arch Linux 64-bit. I have an external
>>> harddisk, with a btrfs filessystem on it. Just now, after a reboot, I
>>> seem to be unable to mount it.
>>>
>>> KDE gives a message about being unable to find the superblock, trying
>>> to mount it from the command-line gives something similar:
>>>
>>>> mount: /dev/sdc1: can't read superblock
>>>
>>> I do know the last time I used the disk, it may not have been
>>> unmounted cleanly. Could that have caused this current issue? Any
>>> possible remedy? I'm really hoping it is, because that's a 1.5 Tb
>>> external disk...lol.
>>>
>>> Also, dmesg contains:
>>>>
>>>> usb 2-2: new high speed USB device using ehci_hcd and address 8
>>>> usb 2-2: configuration #1 chosen from 1 choice
>>>> scsi10 : SCSI emulation for USB Mass Storage devices
>>>> usb-storage: device found at 8
>>>> usb-storage: waiting for device to settle before scanning
>>>> scsi 10:0:0:0: Direct-Access     WDC WD15 EADS-00P8B0           PQ: 0 ANSI: 2
>>>> sd 10:0:0:0: Attached scsi generic sg2 type 0
>>>> usb-storage: device scan complete
>>>> sd 10:0:0:0: [sdc] 2930277168 512-byte logical blocks: (1.50 TB/1.36 TiB)
>>>> sd 10:0:0:0: [sdc] Write Protect is off
>>>> sd 10:0:0:0: [sdc] Mode Sense: 38 00 00 00
>>>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>>>  sdc: sdc1
>>>> sd 10:0:0:0: [sdc] Assuming drive cache: write through
>>>> sd 10:0:0:0: [sdc] Attached SCSI disk
>>>> device label tessier-ashpool devid 1 transid 4882 /dev/sdc1
>>>> open /dev/sdd1 failed
>>>
>>> Cheers,
>>> Victor
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>


-- 
taruisi

Re: Btrfs - Unable to mount, can't read superblock?

[Chris Mason]

On Mon, Feb 15, 2010 at 07:16:51PM +0900, TARUISI Hiroaki wrote:
> That's good for you. :)
> 
> It may be surprising that simple suspending causes disk error.
> I posted a simple patch jast a week ago, I hope it will be
> merged soon.

I have this in the .34 queue, thanks!

-chris