partitions

hi guys, could we implement raid partitions?
for example:
mdadm --create /dev/md0 --level=3D1 --devices /dev/sda /dev/sdb
fdisk /dev/md0
create pratition 1,2,3,4

mkfs.ext4 /dev/md0p1
mkfs.ext4 /dev/md0p2
mkfs.ext4 /dev/md0p3
mkfs.ext4 /dev/md0p4

?? any idea? could we implement it?
there=B4s a TODO list for linux software raid?

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Spadim Technology / SPAEmpresarial
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Re: partitions

i read about lvm (not a lot), it work with grub and lilo right?

2011/1/28 Doug Dumitru :
> This functionality already exists with two different solutions.
>
> The "normal" solution is to use LVM on top of /dev/md0.  LVM is =
usually
> considered "better" than partitions because it is a more flexible app=
roach.
>
> If you have to have partitions, you can do this with:
>
>     ... create partitions 1,2,3,4
>     kpartx -a /dev/md0
>     mkfs.ext4 /dev/mapper/md0p1
>     mkfs.ext4 /dev/mapper/md0p2
>     mkfs.ext4 /dev/mapper/md0p3
>     mkfs.ext4 /dev/mapper/md0p4
>
> This is not really a "linux-raid" issue, but just how to apply block =
device
> mapping tools.
>
> Doug Dumitru
> EasyCo LLC
>
> On Fri, Jan 28, 2011 at 1:24 PM, Roberto Spadim r>
> wrote:
>>
>> hi guys, could we implement raid partitions?
>> for example:
>> mdadm --create /dev/md0 --level=3D1 --devices /dev/sda /dev/sdb
>> fdisk /dev/md0
>> create pratition 1,2,3,4
>>
>> mkfs.ext4 /dev/md0p1
>> mkfs.ext4 /dev/md0p2
>> mkfs.ext4 /dev/md0p3
>> mkfs.ext4 /dev/md0p4
>>
>> ?? any idea? could we implement it?
>> thereæ„=80 a TODO list for linux software raid?
>>
>> --
>> Roberto Spadim
>> Spadim Technology / SPAEmpresarial
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-raid=
" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.h=
tml
>
>
>
> --
> Doug Dumitru
> EasyCo LLC
>
>



--=20
Roberto Spadim
Spadim Technology / SPAEmpresarial
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Re: partitions

On Fri, Jan 28, 2011 at 1:45 PM, Roberto Spadim =
wrote:
>
> i read about lvm (not a lot), it work with grub and lilo right?

grub and lilo need a "plain" boot partition. the raid setup is later
and your root partition can definitely be inside of an LVM volume.
This is the default install for many distros.

Doug Dumitru
EasyCo LLC

>
> 2011/1/28 Doug Dumitru :
> > This functionality already exists with two different solutions.
> >
> > The "normal" solution is to use LVM on top of /dev/md0.  LVM i=
s usually
> > considered "better" than partitions because it is a more flexible a=
pproach.
> >
> > If you have to have partitions, you can do this with:
> >
> >     ... create partitions 1,2,3,4
> >     kpartx -a /dev/md0
> >     mkfs.ext4 /dev/mapper/md0p1
> >     mkfs.ext4 /dev/mapper/md0p2
> >     mkfs.ext4 /dev/mapper/md0p3
> >     mkfs.ext4 /dev/mapper/md0p4
> >
> > This is not really a "linux-raid" issue, but just how to apply bloc=
k device
> > mapping tools.
> >
> > Doug Dumitru
> > EasyCo LLC
> >
> > On Fri, Jan 28, 2011 at 1:24 PM, Roberto Spadim br>
> > wrote:
> >>
> >> hi guys, could we implement raid partitions?
> >> for example:
> >> mdadm --create /dev/md0 --level=3D1 --devices /dev/sda /dev/sdb
> >> fdisk /dev/md0
> >> create pratition 1,2,3,4
> >>
> >> mkfs.ext4 /dev/md0p1
> >> mkfs.ext4 /dev/md0p2
> >> mkfs.ext4 /dev/md0p3
> >> mkfs.ext4 /dev/md0p4
> >>
> >> ?? any idea? could we implement it?
> >> thereæ„=80 a TODO list for linux software raid?
> >>
> >> --
> >> Roberto Spadim
> >> Spadim Technology / SPAEmpresarial
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-ra=
id" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info=
html
> >
> >
> >
> > --
> > Doug Dumitru
> > EasyCo LLC
> >
> >
>
>
>
> --
> Roberto Spadim
> Spadim Technology / SPAEmpresarial



--
Doug Dumitru
EasyCo LLC
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Re: partitions

humm.... ok... no problems i was think about making software raid 100%
compatible with hardware raid (transparently) but it´s not just a =
plug
and play, no problems it´s easy :)

2011/1/28 Doug Dumitru :
> On Fri, Jan 28, 2011 at 1:45 PM, Roberto Spadim r> wrote:
>>
>> i read about lvm (not a lot), it work with grub and lilo right?
>
> grub and lilo need a "plain" boot partition.  the raid setup is =
later
> and your root partition can definitely be inside of an LVM volume.
> This is the default install for many distros.
>
> Doug Dumitru
> EasyCo LLC
>
>>
>> 2011/1/28 Doug Dumitru :
>> > This functionality already exists with two different solutions.
>> >
>> > The "normal" solution is to use LVM on top of /dev/md0.  LVM =
is usually
>> > considered "better" than partitions because it is a more flexible =
approach.
>> >
>> > If you have to have partitions, you can do this with:
>> >
>> >     ... create partitions 1,2,3,4
>> >     kpartx -a /dev/md0
>> >     mkfs.ext4 /dev/mapper/md0p1
>> >     mkfs.ext4 /dev/mapper/md0p2
>> >     mkfs.ext4 /dev/mapper/md0p3
>> >     mkfs.ext4 /dev/mapper/md0p4
>> >
>> > This is not really a "linux-raid" issue, but just how to apply blo=
ck device
>> > mapping tools.
>> >
>> > Doug Dumitru
>> > EasyCo LLC
>> >
>> > On Fri, Jan 28, 2011 at 1:24 PM, Roberto Spadim m.br>
>> > wrote:
>> >>
>> >> hi guys, could we implement raid partitions?
>> >> for example:
>> >> mdadm --create /dev/md0 --level=3D1 --devices /dev/sda /dev/sdb
>> >> fdisk /dev/md0
>> >> create pratition 1,2,3,4
>> >>
>> >> mkfs.ext4 /dev/md0p1
>> >> mkfs.ext4 /dev/md0p2
>> >> mkfs.ext4 /dev/md0p3
>> >> mkfs.ext4 /dev/md0p4
>> >>
>> >> ?? any idea? could we implement it?
>> >> thereæ„=80 a TODO list for linux software raid?
>> >>
>> >> --
>> >> Roberto Spadim
>> >> Spadim Technology / SPAEmpresarial
>> >> --
>> >> To unsubscribe from this list: send the line "unsubscribe linux-r=
aid" in
>> >> the body of a message to majordomo@vger.kernel.org
>> >> More majordomo info at  http://vger.kernel.org/majordomo-inf=
o.html
>> >
>> >
>> >
>> > --
>> > Doug Dumitru
>> > EasyCo LLC
>> >
>> >
>>
>>
>>
>> --
>> Roberto Spadim
>> Spadim Technology / SPAEmpresarial
>
>
>
> --
> Doug Dumitru
> EasyCo LLC
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid"=
in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.ht=
ml
>



--=20
Roberto Spadim
Spadim Technology / SPAEmpresarial
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Re: partitions

On Fri, Jan 28, 2011 at 4:39 PM, Doug Dumitru wrote:
>
> grub and lilo need a "plain" boot partition. =A0the raid setup is lat=
er
..

One exception: Grub (and perhaps LILO) can boot from a RAID1 partition
because the individual partition looks like a plain file system. It
requires v 0.9 metadata which stores the superblock at the end of the
partition. (Don't ask me how I know! ;) )

I have used LVM to partition a RAID5. I have no idea if it adds
significant overhead vs. partitioning the RAID itself if that were
possible. It was arcane enough for me to not care to do it again. It
appears to have some powerful capabilities that were not needed by me.

best,
hank

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Re: partitions

It already is.

On 01/28/2011 04:24 PM, Roberto Spadim wrote:
> hi guys, could we implement raid partitions?
> for example:
> mdadm --create /dev/md0 --level=3D1 --devices /dev/sda /dev/sdb
> fdisk /dev/md0
> create pratition 1,2,3,4
>
> mkfs.ext4 /dev/md0p1
> mkfs.ext4 /dev/md0p2
> mkfs.ext4 /dev/md0p3
> mkfs.ext4 /dev/md0p4
>
> ?? any idea? could we implement it?
> there=B4s a TODO list for linux software raid?
>

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Re: partitions

On 01/28/2011 08:22 PM, Hank Barta wrote:
> One exception: Grub (and perhaps LILO) can boot from a RAID1 partition
> because the individual partition looks like a plain file system. It
> requires v 0.9 metadata which stores the superblock at the end of the
> partition. (Don't ask me how I know! ;) )

Grub2 can boot from raid1, raid0, raid5, it doesn't care ( without a
plain /boot partition ).

> I have used LVM to partition a RAID5. I have no idea if it adds
> significant overhead vs. partitioning the RAID itself if that were
> possible. It was arcane enough for me to not care to do it again. It
> appears to have some powerful capabilities that were not needed by me.

With LVM you can do online resize and moves, and don't run into issues
trying to expand a partition and having to take forever to move an
adjacent one over to make room, or other issues with the 4 primary
partition limit. I find these to be pretty handy.

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Re: partitions

nice i don't know if LVM make a more overhead but it's a very feature
=3D) thanks again guys!

2011/1/29 Phillip Susi :
> On 01/28/2011 08:22 PM, Hank Barta wrote:
>>
>> One exception: Grub (and perhaps LILO) can boot from a RAID1 partiti=
on
>> because the individual partition looks like a plain file system. It
>> requires v 0.9 metadata which stores the superblock at the end of th=
e
>> partition. (Don't ask me how I know! ;) )
>
> Grub2 can boot from raid1, raid0, raid5, it doesn't care ( without a =
plain
> /boot partition ).
>
>> I have used LVM to partition a RAID5. I have no idea if it adds
>> significant overhead vs. partitioning the RAID itself if that were
>> possible. It was arcane enough for me to not care to do it again. It
>> appears to have some powerful capabilities that were not needed by m=
e.
>
> With LVM you can do online resize and moves, and don't run into issue=
s
> trying to expand a partition and having to take forever to move an ad=
jacent
> one over to make room, or other issues with the 4 primary partition l=
imit.
> =A0I find these to be pretty handy.
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid"=
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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Roberto Spadim
Spadim Technology / SPAEmpresarial
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