[linux-lvm] lvm on linux RAID5?

[linux-lvm] lvm on linux RAID5?

[Anders Henriksson]

Hej,

I have tried scanning the list archive and re-read the documentation but
still....

I want to run lvm over four linux raid5 devices, can I just treat the
raid devices as discs? i.e. run pvcreate on them directly and go on from
there.

I am running a linux 7.3 server almost out of the box.

/Anders

Re: [linux-lvm] lvm on linux RAID5?

[Patrick Boutilier]

Anders,

That should work. I run LVM on top of one raid5 device but I don't see 
why it wouldn't work over 4 of them.

For example run pvcreate on /dev/sda, then /dev/sdb, etc..

What kind of machine did you manage to get 4 RAID5 arrays into?



Anders Henriksson wrote:

> Hej,
>
> I have tried scanning the list archive and re-read the documentation but
> still....
>
> I want to run lvm over four linux raid5 devices, can I just treat the
> raid devices as discs? i.e. run pvcreate on them directly and go on from
> there.
>
> I am running a linux 7.3 server almost out of the box.
>
> /Anders
>
>
>
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Re: [linux-lvm] lvm on linux RAID5?

[Andreas Baier]

Hi,

here´s the quick way

1. define your raid-partitions with fdisk by asgning them 0xfd
2. setup your /etc/raidtab
3. issuning raidstart -c /etc/raidtab should start  your md-device
4. asume you just use one md device you would now have md0 as
    your raid-device
5. Now you can pvcreate /dev/md0
6. than vgcreate whatevervgname /dev/md0
7. lvcreate what you like on that vg


for creating the raid5 have a look at that sample:


# Sample raid-5 configuration
raiddev                 /dev/md0
raid-level              5
nr-raid-disks           3
chunk-size              32

# Parity placement algorithm

#parity-algorithm       left-asymmetric
parity-algorithm        left-symmetric
#parity-algorithm       right-asymmetric
#parity-algorithm       right-symmetric

# Spare disks for hot reconstruction (not supported yet)
#nr-spare-disks         0

device                  /dev/hda1
raid-disk               0

device                  /dev/hdb1
raid-disk               1

device                  /dev/hdc1
raid-disk               2


Best regards


Anders Henriksson wrote:

> Hej,
> 
> I have tried scanning the list archive and re-read the documentation but
> still....
> 
> I want to run lvm over four linux raid5 devices, can I just treat the
> raid devices as discs? i.e. run pvcreate on them directly and go on from
> there.
> 
> I am running a linux 7.3 server almost out of the box.
> 
> /Anders
> 
> 
> 
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> 
> 


-- 
Andreas Baier

Re: [linux-lvm] lvm on linux RAID5?

[Anders Henriksson]

On Wed, 2002-10-16 at 15:28, Patrick Boutilier wrote:
> Anders,
> 
> That should work. I run LVM on top of one raid5 device but I don't see 
> why it wouldn't work over 4 of them.
> 
> For example run pvcreate on /dev/sda, then /dev/sdb, etc..

It seems to work fine, I just tried it and it works smoother than
expected.

> 
> What kind of machine did you manage to get 4 RAID5 arrays into?

It is actually not that hard, take your one array and split it into 4.
I have 4 discs which are split into 4 raid partitions each.

/Anders



> 
> 
> 
> Anders Henriksson wrote:
> 
> > Hej,
> >
> > I have tried scanning the list archive and re-read the documentation but
> > still....
> >
> > I want to run lvm over four linux raid5 devices, can I just treat the
> > raid devices as discs? i.e. run pvcreate on them directly and go on from
> > there.
> >
> > I am running a linux 7.3 server almost out of the box.
> >
> > /Anders
> >
> >
> >
> >
> >
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

Re: [linux-lvm] lvm on linux RAID5?

[Goetz Bock]

On Wed, Oct 16 '02 at 15:02, Anders Henriksson wrote:
> I want to run lvm over four linux raid5 devices, can I just treat the
> raid devices as discs? i.e. run pvcreate on them directly and go on from
> there.
You've more than 12 discs in your box? No? Oh, if you ment you're trying
to run LVM ontop of a 4disk RAID5 drive (using linux md drivers), than
try:

pvcreate /dev/md0

vgcreate ... /dev/md0

lvcreate ... 

I'm running LVM since v1.0.0 ontop of a 6 device RAID5 drive using 2.4.x
MD driver.

> I am running a linux 7.3 server almost out of the box.
And what distribution are you using? But that should not matter.
-- 
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IT Consultant    GNU FDL 1.1    secure mobile Linux everNETting   \ /
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 ASCII Ribbon Campaign against HTML email & microsoft attachments / \

Re: [linux-lvm] lvm on linux RAID5?

[Jon Bendtsen]

Anders Henriksson wrote:
> 
> On Wed, 2002-10-16 at 15:28, Patrick Boutilier wrote:
> > Anders,
> >
> > That should work. I run LVM on top of one raid5 device but I don't see
> > why it wouldn't work over 4 of them.
> >
> > For example run pvcreate on /dev/sda, then /dev/sdb, etc..
> 
> It seems to work fine, I just tried it and it works smoother than
> expected.
> 
> >
> > What kind of machine did you manage to get 4 RAID5 arrays into?
> 
> It is actually not that hard, take your one array and split it into 4.
> I have 4 discs which are split into 4 raid partitions each.

Why would you split the raid, for then just to run LVM ontop of it ?



JonB

Re: [linux-lvm] lvm on linux RAID5?

[Jon Bendtsen]

Goetz Bock wrote:
> 
> On Wed, Oct 16 '02 at 15:02, Anders Henriksson wrote:
> > I want to run lvm over four linux raid5 devices, can I just treat the
> > raid devices as discs? i.e. run pvcreate on them directly and go on from
> > there.
> You've more than 12 discs in your box? No? Oh, if you ment you're trying
> to run LVM ontop of a 4disk RAID5 drive (using linux md drivers), than
> try:

No, he doesnt have 12 disks. He wrote he have 4 which is splitted into
4.
aka, 4 disks made into a raid5, and then 4 partitions, and he wants to
run
LVM ontop of (one of) those partitions. (rather silly to split it into
partitions
for then to run LVM...)




JonB

Re: [linux-lvm] lvm on linux RAID5?

[Anders Henriksson]

<snip>

> > > What kind of machine did you manage to get 4 RAID5 arrays into?
> > 
> > It is actually not that hard, take your one array and split it into 4.
> > I have 4 discs which are split into 4 raid partitions each.
> 
> Why would you split the raid, for then just to run LVM ontop of it ?

Just to have the flexibility to shrink the array and reuse partitions
for other purposes if needed, the same reason I have for wanting to use
lvm in the first place, just plain simple flexibility.

/Anders 
> 
> 
> 
> JonB
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 

Re: [linux-lvm] lvm on linux RAID5?

[Steven Lembark]

-- Anders Henriksson <anders.henriksson@xelin.se>

> Hej,
>
> I have tried scanning the list archive and re-read the documentation but
> still....
>
> I want to run lvm over four linux raid5 devices, can I just treat the
> raid devices as discs? i.e. run pvcreate on them directly and go on from
> there.
>
> I am running a linux 7.3 server almost out of the box.
>
> /Anders
>
>
>
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/



--
Steven Lembark                               2930 W. Palmer
Workhorse Computing                       Chicago, IL 60647
                                            +1 800 762 1582