Question about blocksize, I want to use 16k

Question about blocksize, I want to use 16k

[Mike Audia]

Wanting to use 16k block for my btrfs, I did so via:

# mkfs.btrfs -l 16k -s 16k -L arch64 -f /dev/sda3

WARNING! - Btrfs v0.20-rc1-253-g7854c8b IS EXPERIMENTAL
WARNING! - see http://btrfs.wiki.kernel.org before using

Detected a SSD, turning off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
fs created label arch64 on /dev/sda3
 nodesize 16384 leafsize 16384 sectorsize 16384 size 119.00GB
Btrfs v0.20-rc1-253-g7854c8b

But when I tried to mount it, dmesg showed these errors aobut sector sizes:

# mount /dev/sda3 /newarch
mount: wrong fs type, bad option, bad superblock on /dev/sda3,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.

[ 1463.366701] device label arch64 devid 1 transid 4 /dev/sda3
[ 1463.367186] btrfs: disk space caching is enabled
[ 1463.367189] btrfs flagging fs with big metadata feature
[ 1463.367539] btrfs: Incompatible sector size(16384) found on sda3
[ 1463.419215] btrfs: open_ctree failed

So I made the filesystem like this and all is well... what am I missing?

# mkfs.btrfs -l 16k -L arch64 -f /dev/sda3       

WARNING! - Btrfs v0.20-rc1-253-g7854c8b IS EXPERIMENTAL
WARNING! - see http://btrfs.wiki.kernel.org before using

Detected a SSD, turning off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
fs created label arch64 on /dev/sda3
 nodesize 16384 leafsize 16384 sectorsize 4096 size 119.00GB
Btrfs v0.20-rc1-253-g7854c8b

Re: Question about blocksize, I want to use 16k

[Chris Murphy]

On Aug 10, 2013, at 9:42 AM, Mike Audia <mikey_a@gmx.com> wrote:

> -s 16k

One answer is the drive doesn't expose a 16KB sector. It's basically lying when it reports a 512 byte physical sector, but there isn't anything that can be done about this on the software side. The other answer:

http://permalink.gmane.org/gmane.comp.file-systems.btrfs/20746



Chris Murphy

Re: Question about blocksize, I want to use 16k

[Chris Murphy]

On Aug 10, 2013, at 10:17 AM, Chris Murphy <lists@colorremedies.com> wrote:

> 
> On Aug 10, 2013, at 9:42 AM, Mike Audia <mikey_a@gmx.com> wrote:
> 
>> -s 16k
> 
> One answer is the drive doesn't expose a 16KB sector. It's basically lying when it reports a 512 byte physical sector, but there isn't anything that can be done about this on the software side. The other answer:
> 
> http://permalink.gmane.org/gmane.comp.file-systems.btrfs/20746

And also:
http://permalink.gmane.org/gmane.comp.file-systems.btrfs/19661


Chris Murphy