btrfs doesn't format eMMC if previous filesystem is ext4

btrfs doesn't format eMMC if previous filesystem is ext4

[Ankur Tank]

Hi,

I wanted to test btrfs on the eMMC of beaglebone black based custom board.
Precondition: eMMC is formatted with ext4 filesystem
Use case:
        Format eMMC with mkfs.btrfs  -L  <label>  <dev>
Result:
        Mkfs.btrfs denies formatting eMMC because its existing filesystem

# mkfs.btrfs -L "1storage" /dev/mmcblk0p2
/dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
Error: Use the -f option to force overwrite.

If I add "-f" its possible to format the eMMC.

# mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2
Detected a SSD, turning off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
Btrfs v3.17
See http://btrfs.wiki.kernel.org for more information.

Performing full device TRIM (1.72GiB) ...
Turning ON incompat feature 'extref': increased hardlink limit per file to 65536
[273917.692896] btrfs: device label 1storage devid 1 transid 3 /dev/mmcblk0p2
fs created label 1storage on /dev/mmcblk0p2
        nodesize 16384 leafsize 16384 sectorsize 4096 size 1.72GiB

I had downloaded debian package from following link
https://packages.debian.org/sid/armhf/btrfs-tools/download

Is it a bug ? or I am missing something ?

Thank you,

Regards,
Ankur
L&T Technology Services Ltd

www.LntTechservices.com<http://www.lnttechservices.com/>

This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.

Re: btrfs doesn't format eMMC if previous filesystem is ext4

[Zygo Blaxell]

[-- Attachment #1: Type: text/plain, Size: 2153 bytes --]

On Fri, Dec 26, 2014 at 03:24:59PM +0000, Ankur Tank wrote:
> I wanted to test btrfs on the eMMC of beaglebone black based custom board.
> Precondition: eMMC is formatted with ext4 filesystem
> Use case:
>         Format eMMC with mkfs.btrfs  -L  <label>  <dev>
> Result:
>         Mkfs.btrfs denies formatting eMMC because its existing filesystem
> 
> # mkfs.btrfs -L "1storage" /dev/mmcblk0p2
> /dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
> Error: Use the -f option to force overwrite.
> 
> If I add "-f" its possible to format the eMMC.

It seems to be a feature.  mkfs.btrfs will test the device with libblkid
to see if there is a filesystem present to prevent administrator mistakes.
If libblkid can identify and device, it will prevent format without -f.

If you're doing an automated script, you need the -f.  libblkid isn't
particularly reliable and can false-positive on random data (e.g. the
HFS module can detect a filesystem that is not there).  If you're doing
tests that involve reformatting the filesystem in a loop, you need the -f.

> # mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2
> Detected a SSD, turning off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
> Btrfs v3.17
> See http://btrfs.wiki.kernel.org for more information.
> 
> Performing full device TRIM (1.72GiB) ...
> Turning ON incompat feature 'extref': increased hardlink limit per file to 65536
> [273917.692896] btrfs: device label 1storage devid 1 transid 3 /dev/mmcblk0p2
> fs created label 1storage on /dev/mmcblk0p2
>         nodesize 16384 leafsize 16384 sectorsize 4096 size 1.72GiB
> 
> I had downloaded debian package from following link
> https://packages.debian.org/sid/armhf/btrfs-tools/download
> 
> Is it a bug ? or I am missing something ?

If your device is small or solid-state, btrfs will change the default
options (mixed-metadata, no duplicate metadata).

"extref" is a feature that enables large numbers of hardlinks to a
single file.  You can leave it enabled-it's unlikely your devices
will ever see a kernel old enough that it's not compatible.


[-- Attachment #2: Digital signature --]
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Re: btrfs doesn't format eMMC if previous filesystem is ext4

[Anand Jain]

On 12/26/2014 11:24 PM, Ankur Tank wrote:
> Hi,
>
> I wanted to test btrfs on the eMMC of beaglebone black based custom board.
> Precondition: eMMC is formatted with ext4 filesystem
> Use case:
>          Format eMMC with mkfs.btrfs  -L  <label>  <dev>
> Result:
>          Mkfs.btrfs denies formatting eMMC because its existing filesystem
>
> # mkfs.btrfs -L "1storage" /dev/mmcblk0p2
> /dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
> Error: Use the -f option to force overwrite.
>
> If I add "-f" its possible to format the eMMC.
>
> # mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2
> Detected a SSD, turning off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
> Btrfs v3.17
> See http://btrfs.wiki.kernel.org for more information.
>
> Performing full device TRIM (1.72GiB) ...
> Turning ON incompat feature 'extref': increased hardlink limit per file to 65536
> [273917.692896] btrfs: device label 1storage devid 1 transid 3 /dev/mmcblk0p2
> fs created label 1storage on /dev/mmcblk0p2
>          nodesize 16384 leafsize 16384 sectorsize 4096 size 1.72GiB
>
> I had downloaded debian package from following link
> https://packages.debian.org/sid/armhf/btrfs-tools/download
>
> Is it a bug ? or I am missing something ?

  I don't see any bug. Can you be more specific ? Thanks.

> Thank you,
>
> Regards,
> Ankur
> L&T Technology Services Ltd
>
> www.LntTechservices.com<http://www.lnttechservices.com/>
>
> This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.
> --
> 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 doesn't format eMMC if previous filesystem is ext4

[Ankur Tank]

Hi Anand,

Precondition : Previous filesystem on eMMC  was --- ext4----
Use case : Now format eMMC to btrfs format, using ---mkfs.btrfs---
mkfs.btrfs denies formatting eMMC telling that eMMC contain an existing filesystem(ext4).

In my opinion mkfs.btrfs must allow to format eMMC with btrfs even if there is other filesystem on it.

mkfs.ext4 and mkfs.f2fs does allow formatting even if eMMC contains some other file system on it.

Note: If I add "-f" option mkfs.btrf does allow formatting eMMC to btrfs filesytem.

Regards,
Ankur
-----Original Message-----
From: Anand Jain [mailto:Anand.Jain@oracle.com]
Sent: Monday, December 29, 2014 8:21 AM
To: Ankur Tank; linux-btrfs@vger.kernel.org
Subject: Re: btrfs doesn't format eMMC if previous filesystem is ext4



On 12/26/2014 11:24 PM, Ankur Tank wrote:
> Hi,
>
> I wanted to test btrfs on the eMMC of beaglebone black based custom board.
> Precondition: eMMC is formatted with ext4 filesystem Use case:
>          Format eMMC with mkfs.btrfs  -L  <label>  <dev>
> Result:
>          Mkfs.btrfs denies formatting eMMC because its existing
> filesystem
>
> # mkfs.btrfs -L "1storage" /dev/mmcblk0p2
> /dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
> Error: Use the -f option to force overwrite.
>
> If I add "-f" its possible to format the eMMC.
>
> # mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2 Detected a SSD, turning
> off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
> Btrfs v3.17
> See http://btrfs.wiki.kernel.org for more information.
>
> Performing full device TRIM (1.72GiB) ...
> Turning ON incompat feature 'extref': increased hardlink limit per
> file to 65536 [273917.692896] btrfs: device label 1storage devid 1
> transid 3 /dev/mmcblk0p2 fs created label 1storage on /dev/mmcblk0p2
>          nodesize 16384 leafsize 16384 sectorsize 4096 size 1.72GiB
>
> I had downloaded debian package from following link
> https://packages.debian.org/sid/armhf/btrfs-tools/download
>
> Is it a bug ? or I am missing something ?

  I don't see any bug. Can you be more specific ? Thanks.

> Thank you,
>
> Regards,
> Ankur
> L&T Technology Services Ltd
>
> www.LntTechservices.com<http://www.lnttechservices.com/>
>
> This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.
> --
> 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
>
L&T Technology Services Ltd

www.LntTechservices.com<http://www.lnttechservices.com/>

This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.

Re: btrfs doesn't format eMMC if previous filesystem is ext4

[Martin Steigerwald]

Am Montag, 29. Dezember 2014, 07:15:11 schrieb Ankur Tank:

> > -----Original Message-----
> > From: Anand Jain [mailto:Anand.Jain@oracle.com]
> > Sent: Monday, December 29, 2014 8:21 AM
> > To: Ankur Tank; linux-btrfs@vger.kernel.org
> > Subject: Re: btrfs doesn't format eMMC if previous filesystem is ext4
> > 
> > On 12/26/2014 11:24 PM, Ankur Tank wrote:
> > > Hi,
> > > 
> > > I wanted to test btrfs on the eMMC of beaglebone black based custom
> > > board.
> > > 
> > > Precondition: eMMC is formatted with ext4 filesystem Use case:
> > >          Format eMMC with mkfs.btrfs  -L  <label>  <dev>
> > > 
> > > Result:
> > >          Mkfs.btrfs denies formatting eMMC because its existing
> > > 
> > > filesystem
> > > 
> > > # mkfs.btrfs -L "1storage" /dev/mmcblk0p2
> > > /dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
> > > Error: Use the -f option to force overwrite.
> > > 
> > > If I add "-f" its possible to format the eMMC.
> > > 
> > > # mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2 Detected a SSD, turning
> > > off metadata duplication.  Mkfs with -m dup if you want to force
> > > metadata duplication. Btrfs v3.17
> > > See http://btrfs.wiki.kernel.org for more information.
> > > 
> > > Performing full device TRIM (1.72GiB) ...
> > > Turning ON incompat feature 'extref': increased hardlink limit per
> > > file to 65536 [273917.692896] btrfs: device label 1storage devid 1
> > > transid 3 /dev/mmcblk0p2 fs created label 1storage on /dev/mmcblk0p2
> > > 
> > >          nodesize 16384 leafsize 16384 sectorsize 4096 size 1.72GiB
> > > 
> > > I had downloaded debian package from following link
> > > https://packages.debian.org/sid/armhf/btrfs-tools/download
> > > 
> > > Is it a bug ? or I am missing something ?
> > > 
> >   I don't see any bug. Can you be more specific ? Thanks.

> Hi Anand,
> 
> Precondition : Previous filesystem on eMMC  was --- ext4----
> Use case : Now format eMMC to btrfs format, using ---mkfs.btrfs---
> mkfs.btrfs denies formatting eMMC telling that eMMC contain an existing filesystem(ext4).
> 
> In my opinion mkfs.btrfs must allow to format eMMC with btrfs even if there is other filesystem on it.
> 
> mkfs.ext4 and mkfs.f2fs does allow formatting even if eMMC contains some other file system on it.
> 
> Note: If I add "-f" option mkfs.btrf does allow formatting eMMC to btrfs filesytem.

Thats intended.

It is like mkfs.xfs does it as well.

And I really like this.

Don´t just format an existing filesystem without an explicit request to do
so. I always disliked that on Linux / UNIX tools don´t ask at least once for
dangerous operations. Well some do very toroughly:

merkaba:~> LANG=C apt-get purge bash
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  bash* foomatic-db-engine*
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  bash
0 upgraded, 0 newly installed, 2 to remove and 2 not upgraded.
After this operation, 5887 kB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase 'Yes, do as I say!'
 ?]


Yeah, I know the saying that "root" should know about own actions, yeah I
think alias rm="rm -i" is too much and doesn´t do much good cause people
are motivated to do "rm -f" then to override it after having been asked a
hundred times for each to delete file and if you want, and yeah I think
alias rm="rm -I" or how Z-Shell does it, is much better, but heck we are all
human beings, so I like being warned on actions that may make a ton of data
inaccessible real fast.

So if you want to script it, use "-f". :)

Ciao,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

RE: btrfs doesn't format eMMC if previous filesystem is ext4

[Ankur Tank]

Thank you for reply Anand & Matrin,

Okay I understand the intention now.
I know it's not the forum to address issues related to mkfs commands
But I think, options used should be same across the mkfs.XXX commands.
Another irregularity is
mkfs.f2fs takes "-l" to apply label, while
mkfs.ext4 take  "-L" to apply label.
If one has to write a common script these cases has to be handled separately.

Anyways thank you for help,

Best regards,
Ankur
-----Original Message-----
From: Martin Steigerwald [mailto:Martin@lichtvoll.de]
Sent: Monday, December 29, 2014 3:09 PM
To: Ankur Tank
Cc: Anand Jain; linux-btrfs@vger.kernel.org
Subject: Re: btrfs doesn't format eMMC if previous filesystem is ext4

Am Montag, 29. Dezember 2014, 07:15:11 schrieb Ankur Tank:

> > -----Original Message-----
> > From: Anand Jain [mailto:Anand.Jain@oracle.com]
> > Sent: Monday, December 29, 2014 8:21 AM
> > To: Ankur Tank; linux-btrfs@vger.kernel.org
> > Subject: Re: btrfs doesn't format eMMC if previous filesystem is
> > ext4
> >
> > On 12/26/2014 11:24 PM, Ankur Tank wrote:
> > > Hi,
> > >
> > > I wanted to test btrfs on the eMMC of beaglebone black based
> > > custom board.
> > >
> > > Precondition: eMMC is formatted with ext4 filesystem Use case:
> > >          Format eMMC with mkfs.btrfs  -L  <label>  <dev>
> > >
> > > Result:
> > >          Mkfs.btrfs denies formatting eMMC because its existing
> > >
> > > filesystem
> > >
> > > # mkfs.btrfs -L "1storage" /dev/mmcblk0p2
> > > /dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
> > > Error: Use the -f option to force overwrite.
> > >
> > > If I add "-f" its possible to format the eMMC.
> > >
> > > # mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2 Detected a SSD,
> > > turning off metadata duplication.  Mkfs with -m dup if you want to
> > > force metadata duplication. Btrfs v3.17 See
> > > http://btrfs.wiki.kernel.org for more information.
> > >
> > > Performing full device TRIM (1.72GiB) ...
> > > Turning ON incompat feature 'extref': increased hardlink limit per
> > > file to 65536 [273917.692896] btrfs: device label 1storage devid 1
> > > transid 3 /dev/mmcblk0p2 fs created label 1storage on
> > > /dev/mmcblk0p2
> > >
> > >          nodesize 16384 leafsize 16384 sectorsize 4096 size
> > > 1.72GiB
> > >
> > > I had downloaded debian package from following link
> > > https://packages.debian.org/sid/armhf/btrfs-tools/download
> > >
> > > Is it a bug ? or I am missing something ?
> > >
> >   I don't see any bug. Can you be more specific ? Thanks.

> Hi Anand,
>
> Precondition : Previous filesystem on eMMC  was --- ext4---- Use case
> : Now format eMMC to btrfs format, using ---mkfs.btrfs--- mkfs.btrfs
> denies formatting eMMC telling that eMMC contain an existing filesystem(ext4).
>
> In my opinion mkfs.btrfs must allow to format eMMC with btrfs even if there is other filesystem on it.
>
> mkfs.ext4 and mkfs.f2fs does allow formatting even if eMMC contains some other file system on it.
>
> Note: If I add "-f" option mkfs.btrf does allow formatting eMMC to btrfs filesytem.

Thats intended.

It is like mkfs.xfs does it as well.

And I really like this.

Don´t just format an existing filesystem without an explicit request to do so. I always disliked that on Linux / UNIX tools don´t ask at least once for dangerous operations. Well some do very toroughly:

merkaba:~> LANG=C apt-get purge bash
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  bash* foomatic-db-engine*
WARNING: The following essential packages will be removed.
This should NOT be done unless you know exactly what you are doing!
  bash
0 upgraded, 0 newly installed, 2 to remove and 2 not upgraded.
After this operation, 5887 kB disk space will be freed.
You are about to do something potentially harmful.
To continue type in the phrase 'Yes, do as I say!'
 ?]


Yeah, I know the saying that "root" should know about own actions, yeah I think alias rm="rm -i" is too much and doesn´t do much good cause people are motivated to do "rm -f" then to override it after having been asked a hundred times for each to delete file and if you want, and yeah I think alias rm="rm -I" or how Z-Shell does it, is much better, but heck we are all human beings, so I like being warned on actions that may make a ton of data inaccessible real fast.

So if you want to script it, use "-f". :)

Ciao,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7
L&T Technology Services Ltd

www.LntTechservices.com<http://www.lnttechservices.com/>

This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.

Re: btrfs doesn't format eMMC if previous filesystem is ext4

[Anand Jain]

     That's by design. More over this is nothing specific to eMMC.

Thanks.

On 29/12/2014 15:15, Ankur Tank wrote:
> Hi Anand,
>
> Precondition : Previous filesystem on eMMC  was --- ext4----
> Use case : Now format eMMC to btrfs format, using ---mkfs.btrfs---
> mkfs.btrfs denies formatting eMMC telling that eMMC contain an existing filesystem(ext4).
>
> In my opinion mkfs.btrfs must allow to format eMMC with btrfs even if there is other filesystem on it.
>
> mkfs.ext4 and mkfs.f2fs does allow formatting even if eMMC contains some other file system on it.
>
> Note: If I add "-f" option mkfs.btrf does allow formatting eMMC to btrfs filesytem.
>
> Regards,
> Ankur
> -----Original Message-----
> From: Anand Jain [mailto:Anand.Jain@oracle.com]
> Sent: Monday, December 29, 2014 8:21 AM
> To: Ankur Tank; linux-btrfs@vger.kernel.org
> Subject: Re: btrfs doesn't format eMMC if previous filesystem is ext4
>
>
>
> On 12/26/2014 11:24 PM, Ankur Tank wrote:
>> Hi,
>>
>> I wanted to test btrfs on the eMMC of beaglebone black based custom board.
>> Precondition: eMMC is formatted with ext4 filesystem Use case:
>>           Format eMMC with mkfs.btrfs  -L  <label>  <dev>
>> Result:
>>           Mkfs.btrfs denies formatting eMMC because its existing
>> filesystem
>>
>> # mkfs.btrfs -L "1storage" /dev/mmcblk0p2
>> /dev/mmcblk0p2 appears to contain an existing filesystem (ext4).
>> Error: Use the -f option to force overwrite.
>>
>> If I add "-f" its possible to format the eMMC.
>>
>> # mkfs.btrfs -f -L "1storage" /dev/mmcblk0p2 Detected a SSD, turning
>> off metadata duplication.  Mkfs with -m dup if you want to force metadata duplication.
>> Btrfs v3.17
>> See http://btrfs.wiki.kernel.org for more information.
>>
>> Performing full device TRIM (1.72GiB) ...
>> Turning ON incompat feature 'extref': increased hardlink limit per
>> file to 65536 [273917.692896] btrfs: device label 1storage devid 1
>> transid 3 /dev/mmcblk0p2 fs created label 1storage on /dev/mmcblk0p2
>>           nodesize 16384 leafsize 16384 sectorsize 4096 size 1.72GiB
>>
>> I had downloaded debian package from following link
>> https://packages.debian.org/sid/armhf/btrfs-tools/download
>>
>> Is it a bug ? or I am missing something ?
>    I don't see any bug. Can you be more specific ? Thanks.
>
>> Thank you,
>>
>> Regards,
>> Ankur
>> L&T Technology Services Ltd
>>
>> www.LntTechservices.com<http://www.lnttechservices.com/>
>>
>> This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.
>> --
>> 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
>>
> L&T Technology Services Ltd
>
> www.LntTechservices.com<http://www.lnttechservices.com/>
>
> This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.
> --
> 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 doesn't format eMMC if previous filesystem is ext4

[Martin Steigerwald]

Am Montag, 29. Dezember 2014, 09:55:13 schrieb Ankur Tank:
> Thank you for reply Anand & Matrin,
> 
> Okay I understand the intention now.
> I know it's not the forum to address issues related to mkfs commands
> But I think, options used should be same across the mkfs.XXX commands.
> Another irregularity is
> mkfs.f2fs takes "-l" to apply label, while
> mkfs.ext4 take  "-L" to apply label.
> If one has to write a common script these cases has to be handled separately.
> 
> Anyways thank you for help,

Well, it is *one* of the forums. For that you probably need to CC every
filesystem development mailing list :) or as an alternative the common
fsdevel mailing list.

And yes, mkfs.reiserfs also takes -l. And the mkfs wrapper does *not* convert
the option. So if you use mkfs -t reiserfs -L it doesn´t work. That is why I
always use the mkfs.<FS> manpage and tool directly.

I think all mkfs tools should do the blkid check and not overwrite an
existing filesystem just so.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

RE: btrfs doesn't format eMMC if previous filesystem is ext4

[Ankur Tank]

Martin,

I agree as of now it's better to refer mkfs.<FS> manpage and use it appropriately.
I will write separate email to fsdevel mailing list.

Thank you,

Regards,
Ankur
-----Original Message-----
From: Martin Steigerwald [mailto:Martin@lichtvoll.de]
Sent: Monday, December 29, 2014 3:48 PM
To: Ankur Tank
Cc: Anand Jain; linux-btrfs@vger.kernel.org
Subject: Re: btrfs doesn't format eMMC if previous filesystem is ext4

Am Montag, 29. Dezember 2014, 09:55:13 schrieb Ankur Tank:
> Thank you for reply Anand & Matrin,
>
> Okay I understand the intention now.
> I know it's not the forum to address issues related to mkfs commands
> But I think, options used should be same across the mkfs.XXX commands.
> Another irregularity is
> mkfs.f2fs takes "-l" to apply label, while
> mkfs.ext4 take  "-L" to apply label.
> If one has to write a common script these cases has to be handled separately.
>
> Anyways thank you for help,

Well, it is *one* of the forums. For that you probably need to CC every filesystem development mailing list :) or as an alternative the common fsdevel mailing list.

And yes, mkfs.reiserfs also takes -l. And the mkfs wrapper does *not* convert the option. So if you use mkfs -t reiserfs -L it doesn´t work. That is why I always use the mkfs.<FS> manpage and tool directly.

I think all mkfs tools should do the blkid check and not overwrite an existing filesystem just so.

--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7
L&T Technology Services Ltd

www.LntTechservices.com<http://www.lnttechservices.com/>

This Email may contain confidential or privileged information for the intended recipient (s). If you are not the intended recipient, please do not use or disseminate the information, notify the sender and delete it from your system.