* Total fs size does not match with the actual size of the setup
@ 2013-10-27 20:09 Lester B
2013-10-27 20:17 ` Hugo Mills
0 siblings, 1 reply; 5+ messages in thread
From: Lester B @ 2013-10-27 20:09 UTC (permalink / raw)
To: linux-btrfs
The btrfs setup only have one device of size 7 GiB but
when I run df, the total size shown is 15 GiB. Running
btrfs --repair displays an error "cache and super
generation don't match, space cache will be invalidated."
How can I correct the total fs size as shown in df?
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Total fs size does not match with the actual size of the setup
2013-10-27 20:09 Total fs size does not match with the actual size of the setup Lester B
@ 2013-10-27 20:17 ` Hugo Mills
2013-10-27 20:27 ` Lester B
0 siblings, 1 reply; 5+ messages in thread
From: Hugo Mills @ 2013-10-27 20:17 UTC (permalink / raw)
To: Lester B; +Cc: linux-btrfs
[-- Attachment #1: Type: text/plain, Size: 1301 bytes --]
On Mon, Oct 28, 2013 at 04:09:18AM +0800, Lester B wrote:
> The btrfs setup only have one device of size 7 GiB but
> when I run df, the total size shown is 15 GiB. Running
> btrfs --repair
I'd recommend not running btrfs check --repair unless you really
know what you're doing, or you've checked with someone knowledgable
and they say you should try it. On a non-broken filesystem (as here),
it's probably OK, though.
> displays an error "cache and super
> generation don't match, space cache will be invalidated."
This is harmless.
> How can I correct the total fs size as shown in df?
You can't. It's an artefact of the fact that you've got a RAID-1
(or RAID-10, or --mixed and DUP) filesystem, and that the standard
kernel interface for df doesn't allow us to report the correct figures
-- see [1] (and the subsequent entry as well) for a more detailed
description.
Hugo.
[1] https://btrfs.wiki.kernel.org/index.php/FAQ#Why_does_df_show_incorrect_free_space_for_my_RAID_volume.3F
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
--- Nothing right in my left brain. Nothing left in ---
my right brain.
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: Total fs size does not match with the actual size of the setup
2013-10-27 20:17 ` Hugo Mills
@ 2013-10-27 20:27 ` Lester B
2013-10-27 21:34 ` Brendan Hide
0 siblings, 1 reply; 5+ messages in thread
From: Lester B @ 2013-10-27 20:27 UTC (permalink / raw)
To: Hugo Mills, Lester B, linux-btrfs
2013/10/28 Hugo Mills <hugo@carfax.org.uk>:
> On Mon, Oct 28, 2013 at 04:09:18AM +0800, Lester B wrote:
>> The btrfs setup only have one device of size 7 GiB but
>> when I run df, the total size shown is 15 GiB. Running
>> btrfs --repair
>
> I'd recommend not running btrfs check --repair unless you really
> know what you're doing, or you've checked with someone knowledgable
> and they say you should try it. On a non-broken filesystem (as here),
> it's probably OK, though.
>
>> displays an error "cache and super
>> generation don't match, space cache will be invalidated."
>
> This is harmless.
>
>> How can I correct the total fs size as shown in df?
>
> You can't. It's an artefact of the fact that you've got a RAID-1
> (or RAID-10, or --mixed and DUP) filesystem, and that the standard
> kernel interface for df doesn't allow us to report the correct figures
> -- see [1] (and the subsequent entry as well) for a more detailed
> description.
>
> Hugo.
>
> [1] https://btrfs.wiki.kernel.org/index.php/FAQ#Why_does_df_show_incorrect_free_space_for_my_RAID_volume.3F
>
> --
> === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
> PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
> --- Nothing right in my left brain. Nothing left in ---
> my right brain.
But my setup is a simple one without any RAID levels or other things so at least
df size column should show the actual size of my setup.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Total fs size does not match with the actual size of the setup
2013-10-27 20:27 ` Lester B
@ 2013-10-27 21:34 ` Brendan Hide
2013-10-27 21:49 ` Lester B
0 siblings, 1 reply; 5+ messages in thread
From: Brendan Hide @ 2013-10-27 21:34 UTC (permalink / raw)
To: Lester B, linux-btrfs; +Cc: Hugo Mills
On 2013/10/27 10:27 PM, Lester B wrote:
> 2013/10/28 Hugo Mills <hugo@carfax.org.uk>:
>> On Mon, Oct 28, 2013 at 04:09:18AM +0800, Lester B wrote:
>>> The btrfs setup only have one device of size 7 GiB but
>>> when I run df, the total size shown is 15 GiB. Running
>>> btrfs --repair
>> I'd recommend not running btrfs check --repair unless you really
>> know what you're doing, or you've checked with someone knowledgable
>> and they say you should try it. On a non-broken filesystem (as here),
>> it's probably OK, though.
>>
>>> displays an error "cache and super
>>> generation don't match, space cache will be invalidated."
>> This is harmless.
>>
>>> How can I correct the total fs size as shown in df?
>> You can't. It's an artefact of the fact that you've got a RAID-1
>> (or RAID-10, or --mixed and DUP) filesystem, and that the standard
>> kernel interface for df doesn't allow us to report the correct figures
>> -- see [1] (and the subsequent entry as well) for a more detailed
>> description.
>>
>> Hugo.
>>
>> [1] https://btrfs.wiki.kernel.org/index.php/FAQ#Why_does_df_show_incorrect_free_space_for_my_RAID_volume.3F
>>
>> --
>> === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
>> PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
>> --- Nothing right in my left brain. Nothing left in ---
>> my right brain.
>
> But my setup is a simple one without any RAID levels or other things so at least
> df size column should show the actual size of my setup.
Could you send us the output of the following?:
btrfs fi df <mountpoint>
(where <mountpoint> is the path where the btrfs is mounted.)
--
__________
Brendan Hide
http://swiftspirit.co.za/
http://www.webafrica.co.za/?AFF1E97
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-10-27 21:49 UTC | newest]
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2013-10-27 20:09 Total fs size does not match with the actual size of the setup Lester B
2013-10-27 20:17 ` Hugo Mills
2013-10-27 20:27 ` Lester B
2013-10-27 21:34 ` Brendan Hide
2013-10-27 21:49 ` Lester B
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