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Cybercool 03-09-2004 05:06 AM

LVM and Raid
I want to works with LVM so i can out in harddisk when the other harddisk are full.
And I want to work with a Software raid so i can mirror the Logical Volume.

Can this be done??

I work with a Debian distribution.

If you need extra info ask me!! I'm here whole day

fractal_chaos 03-09-2004 12:09 PM

i am running raid-5 with LVM on RH9. i do this so that 1) i have some parity in case of disk failure and 2) so that i can add another raid array and addend a LV without having to lose any data. is this the kind of thing you wish to do?

Cybercool 03-10-2004 02:09 AM

Yes that's what I want, only I want work with raid 1 (mirroring)
Do you hace a example or something I can use to set up what I want??

And what must I do first.
Create the Raid or create the LVM??

And thanks for youre help!!

fractal_chaos 03-10-2004 09:00 AM

you should set up the raid configuration first. it is likely that you will only be able to add whole raid arrays in the future (at least 2 for mirroring?), and not simply single disks so keep that in mind when creating your arrays.

after you have your arrays set, linux will see them as individual disks. let's say you have four disks, and you've made two arrays from those disks. linux will call these arrays something like /dev/sda and /dev/sdb and see them as ordinary drives.

you should then create partitions on these "drives." you can do this by fdisk. make sure when you create your partitions to make them of type 8e -- local volume partition.

the next steps involve makeing physical volumes and volume groups, but i shouldn't say any more until i understand what you want to do.

how many disks do you have?

do you want all raid arrays to be under LV managment?

do you want all raid arrays to be combined into one big LV?

Cybercool 03-11-2004 01:57 AM

I will explain what I want!!

I want to set up an Debian fileserver with a raid1 control (mirroring)
But when there's no room on the disks anymore I have to put a new disk into the system.
With LVM you can put a disk into the system and al disks will look as 1 disk.

So i begin with 2 disks.
But I most extend it with 2 more (for mirroring I need 2 more i think) if the first 2 disks are full. But it must al look as 1 disk.
So i don't have a lot of work to change the fileserver.

I also want to work with a SAN or NAS because the server will be a little case.

Do you understand what I explained??

P.S. If I make a raid from 2 disks.
And from those to disks I make LV disks.
Will the new disks that I put in the LV be mirrored??

JZL240I-U 03-11-2004 02:34 AM

Here is some general information pertaining to lvm (and raid):

HTH :)

Cybercool 03-11-2004 02:56 AM

Thanks for the link, but I know them already.

But I can't work it out. Doesn't understand it.

I don't get it when and how I create my raid1 and LVM ect.

Must this be done before debian installatie.
Because when I do it after i lose my data.
But it can't be done before I think.

So al to getter, I'm just stuck!!

JZL240I-U 03-11-2004 03:22 AM

If your raid is to be a hardware solution you sure must do it first.

As I understand it that also holds true for sorftware raid. Only then you can meaningfully create the physical volumes, the volume group and the logical volumes in LVM, since they are to be mirrored as well.

I did it using SuSE's Yast (without raid) painlessly and fast. Don't forget to adapt /etc/fstab after the deed ;).

Cybercool 03-11-2004 03:29 AM

But what is the order.

Because when I make a boot partition and a root partition.
And i install Debian.
And then try to create a logical volume the data from the partition is going to be removed when I change the type from 83 (linux) to 8e (linux lvm)

Can you explain the order of intallatie??

JZL240I-U 03-11-2004 03:49 AM

The order is just as I wrote in my previous post ...

1st you install (hardware) raid
2nd you create the appropriate partitions
3rd you create physical volumes
4th you format the physical volumes (as LVM)
5th you create the volome group(s) and logical volumes
6th you install your distro

Note: the /boot partition should not be managed by the LVM due to problems with the reading of the Kernel from /boot without the LVM-layer of the OS loaded ...

Cybercool 03-11-2004 03:51 AM

ok but, i want to work with software raid.

And do you know how to install and work with lvm in the debian installation??

p.s. sorry If I'm giving you a hard time!!

JZL240I-U 03-11-2004 03:56 AM


Originally posted by Cybercool
ok but, i want to work with software raid.
Look at post #8 of the thread ;)


Originally posted by Cybercool
p.s. sorry If I'm giving you a hard time!!
No problem...

Cybercool 03-11-2004 04:03 AM

But Debian doen'st have Yast!!!

JZL240I-U 03-11-2004 04:08 AM

Do an ftp-install offered by SuSE/Novell...

Either complete it (and overwrite it later with Debian), or break it off after step 5 of my previous posting and carry on with installing Debian.

Cybercool 03-11-2004 04:33 AM

That's not an option.
There has to be a debian way,
I will search for it.

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