2 RAID 1 or 1 RAID 10 for VM Server Host

kuyaz

Hi,

I have server with 2 x 1 TB SSD and 2 x 2 TB SATA.

I want to use this server as VM host.
My questions are :

Can I do RAID 1 for each SSD and SATA?
Can Raid 10 do different size and model (1TB SSD & 2TB SATA)?
What is the best RAID configuration for above use?
Should I go hardware RAID? or MDADM? I heard hardware is slower for SSD RAID?
What filesystem I should use on the host? ext4 or LVM? or other?
If I use CentOS 7, do you recommend XEN / VM for stability and user friendly system?

My aim is to get full speed with SSD for critical VM (database server VM guest, web apps, etc) and less critical VM on sata (mail server VM guest, etc).

Thank you.

Dashrender

You should use RAID 1 and create the two arrays.

While you could create a RAID 10 in many cases you’d be killing the performance of the SSD and not using all the storage of the SATA drives.

kuyaz

so I install the host XEN in ssd with RAID 1? and then add the sata as another raid 1?
How to do it properly?

Thanks.

KOOLER

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

Hi,

I have server with 2 x 1 TB SSD and 2 x 2 TB SATA.

I want to use this server as VM host.
My questions are :

Can I do RAID 1 for each SSD and SATA?

Can Raid 10 do different size and model (1TB SSD & 2TB SATA)?

What is the best RAID configuration for above use?

Should I go hardware RAID? or MDADM? I heard hardware is slower for SSD RAID?

What filesystem I should use on the host? ext4 or LVM? or other?

If I use CentOS 7, do you recommend XEN / VM for stability and user friendly system?

My aim is to get full speed with SSD for critical VM (database server VM guest, web apps, etc) and less critical VM on sata (mail server VM guest, etc).

Thank you.

Don't mix different types of the drives with different performance inside the same pool: you'll limit your resulting performance with the slowest (in your content - HDD).

DustinB3403

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

so I install the host XEN in ssd with RAID 1? and then add the sata as another raid 1?
How to do it properly?

Thanks.

You'd put the hypervisor on the slowest drives you have; hypervisors require almost nothing in terms of performance.

You'd create your storage array where the VM disks reside on the SSDs.

DustinB3403

I'd recommend hardware RAID over MDADM, the system should be fast enough if you aren't already 100% certain on what performance metrics you need to hit.

First create your installation target for the hypervisor on your HDD's, simply raid 1 will be fine.

Create a second array from on your server using the SSD's (raid5 might be a better option for you).

Install XenServer (you likely don't want to install XEN) onto this array.

During the installation process you'll be asked what storage you want to use to store your VM's. Choose the SSD array.

Proceed from here.

JaredBusch

@dustinb3403 said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

Create a second array from on your server using the SSD's (raid5 might be a better option for you).

Since when can you make a RAID5 with 2 drives?

Install XenServer (you likely don't want to install XEN) onto this array.

If he already uses CentOS 7 /RHEL / Fedora, then just use KVM.

DustinB3403

@jaredbusch said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@dustinb3403 said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

Create a second array from on your server using the SSD's (raid5 might be a better option for you).

Since when can you make a RAID5 with 2 drives?

Install XenServer (you likely don't want to install XEN) onto this array.

If he already uses CentOS 7 /RHEL / Fedora, then just use KVM.

Doh, yea didn't notice the 2 drive part. haha..

Harry Lui

What is this VM host will be used for?

You'd want 2 RAID 1, given the drives you have.

NO to RAID 10 with the drives you have.

kuyaz

Will be used for web apps, database, and hostings (whm).

Ok so 2 raid 1 it is then.

Is it better to use mdadm / onboard raid IT mode?
Not sure what IT mode means. Any one can help?

I use supermicron server board

scottalanmiller

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

so I install the host XEN in ssd with RAID 1? and then add the sata as another raid 1?
How to do it properly?

Thanks.

No, you'd install Xen to the slow array, not the fast one.

scottalanmiller

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

Is it better to use mdadm / onboard raid IT mode?

MD is Linux' enterprise software RAID and it is very good.

On board RAID is not at all the same thing and is what you almost always avoid. On board RAID is normally garbage and is most of the time FakeRAID.

scottalanmiller

MDADM is a command line tool for working with MD, it is not itself RAID of any sort.

scottalanmiller

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

What filesystem I should use on the host? ext4 or LVM? or other?

This will depend completely on the hypervisor that you expect to use. But LVM is not a filesystem, LVM is the LVM and goes on before the filesystem. You would not want EXT4 for any virtualization.

So there isn't enough info here to answer the question. But you always want an LVM, and you never want EXT4.

Obsolesce

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

What filesystem I should use on the host? ext4 or LVM? or other?

But you always want an LVM, and you never want EXT4.

When you install Fedora 26 for example, it will use EXT4 by default. So if you're not paying attention, you'll end up with that

scottalanmiller

@tim_g said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

What filesystem I should use on the host? ext4 or LVM? or other?

But you always want an LVM, and you never want EXT4.

When you install Fedora 26 for example, it will use EXT4 by default. So if you're not paying attention, you'll end up with that

Last I knew, that was only on workstations, where it doesn't matter so much. I'm using it on my laptop because... whatever.

Obsolesce

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@tim_g said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

What filesystem I should use on the host? ext4 or LVM? or other?

But you always want an LVM, and you never want EXT4.

When you install Fedora 26 for example, it will use EXT4 by default. So if you're not paying attention, you'll end up with that

Last I knew, that was only on workstations, where it doesn't matter so much. I'm using it on my laptop because... whatever.

It does it on Server too. I just installed F26 minimal a couple days ago... it's using EXT4. I'm redoing it now ^_^

coliver

@tim_g said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@tim_g said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

What filesystem I should use on the host? ext4 or LVM? or other?

But you always want an LVM, and you never want EXT4.

When you install Fedora 26 for example, it will use EXT4 by default. So if you're not paying attention, you'll end up with that

Last I knew, that was only on workstations, where it doesn't matter so much. I'm using it on my laptop because... whatever.

It does it on Server too. I just installed F26 minimal a couple days ago... it's using EXT4. I'm redoing it now ^_^

I think it was using XFS for me. Now I need to check my lab box.

scottalanmiller

@tim_g said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@tim_g said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@scottalanmiller said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

@kuyaz said in 2 RAID 1 or 1 RAID 10 for VM Server Host:

What filesystem I should use on the host? ext4 or LVM? or other?

But you always want an LVM, and you never want EXT4.

When you install Fedora 26 for example, it will use EXT4 by default. So if you're not paying attention, you'll end up with that

Last I knew, that was only on workstations, where it doesn't matter so much. I'm using it on my laptop because... whatever.

It does it on Server too. I just installed F26 minimal a couple days ago... it's using EXT4. I'm redoing it now ^_^

Well then that is just stupid. WTF Fedora.

Obsolesce

This should do the trick: