Hi all,
I have a project where I require to treat a file as a block-device
(specifically, I want a file on an ext3 fs to act as one of the
raid-members in a md-based stripe-set. I know that I can make a
/filesystem/ on a file because both mkfs and mount (with -o loop) will
accept a file as a block-device, but I have found no such function for
mdadm, and am thus asking for a kernel-internal way to re-plug a file
into the block-device layer.
Is this possible?
My current platform i CentOS5, a RHEL5 rebuild (modified 2.6.18-kernel).
-S
--
Simen Thoresen - Dolphin ICS Systems Administrator
On Wed, 22 Oct 2008, Simen Thoresen wrote:
> I have a project where I require to treat a file as a block-device
> (specifically, I want a file on an ext3 fs to act as one of the raid-members
> in a md-based stripe-set. I know that I can make a /filesystem/ on a file
> because both mkfs and mount (with -o loop) will accept a file as a
> block-device, but I have found no such function for mdadm, and am thus asking
> for a kernel-internal way to re-plug a file into the block-device layer.
>
> Is this possible?
Sure! You just have to create the loop device (/dev/loop*) yourself using
losetup(8). `mount -o loop' does it itself behind your back.
With kind regards,
Geert Uytterhoeven
Software Architect
Sony Techsoft Centre Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium
Phone: +32 (0)2 700 8453
Fax: +32 (0)2 700 8622
E-mail: [email protected]
Internet: http://www.sony-europe.com/
A division of Sony Europe (Belgium) N.V.
VAT BE 0413.825.160 · RPR Brussels
Fortis · BIC GEBABEBB · IBAN BE41293037680010
Geert Uytterhoeven wrote:
> On Wed, 22 Oct 2008, Simen Thoresen wrote:
>> I have a project where I require to treat a file as a block-device
>> (specifically, I want a file on an ext3 fs to act as one of the raid-members
>> in a md-based stripe-set. I know that I can make a /filesystem/ on a file
>> because both mkfs and mount (with -o loop) will accept a file as a
>> block-device, but I have found no such function for mdadm, and am thus asking
>> for a kernel-internal way to re-plug a file into the block-device layer.
>>
>> Is this possible?
>
> Sure! You just have to create the loop device (/dev/loop*) yourself using
> losetup(8). `mount -o loop' does it itself behind your back.
Ah! Perfect, thank you.
-S
> With kind regards,
>
> Geert Uytterhoeven
> Software Architect
>
> Sony Techsoft Centre Europe
> The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium
>
> Phone: +32 (0)2 700 8453
> Fax: +32 (0)2 700 8622
> E-mail: [email protected]
> Internet: http://www.sony-europe.com/
>
> A division of Sony Europe (Belgium) N.V.
> VAT BE 0413.825.160 · RPR Brussels
> Fortis · BIC GEBABEBB · IBAN BE41293037680010
--
Simen Thoresen - Dolphin ICS Systems Administrator
also sprach Simen Thoresen <[email protected]> [2008.10.22.1456 +0200]:
> accept a file as a block-device, but I have found no such function
> for mdadm, and am thus asking for a kernel-internal way to
> re-plug a file into the block-device layer.
I suggest you search the web first.
http://en.wikipedia.org/wiki/Loopback_disk_device
--
martin | http://madduck.net/ | http://two.sentenc.es/
"you don't sew with a fork, so i see no reason
to eat with knitting needles."
-- miss piggy, on eating chinese food
spamtraps: [email protected]
martin f krafft wrote:
> also sprach Simen Thoresen <[email protected]> [2008.10.22.1456 +0200]:
>> accept a file as a block-device, but I have found no such function
>> for mdadm, and am thus asking for a kernel-internal way to
>> re-plug a file into the block-device layer.
>
> I suggest you search the web first.
> http://en.wikipedia.org/wiki/Loopback_disk_device
Thank you - I missed googling for the absolutely obvious.
Sigh.
-S
--
Simen Thoresen - Dolphin ICS Systems Administrator