Need some recommendations for a new setup

[guedouarj]

Hey everybody !


I'm making a new server with some VM's, regarding the hardware I have one question :

I have 2 Raptors 150gb to make it raid, but I want to add a 2 * 1TB hard disk for data storage (raid too on the same controller but second raid partition ), is it possible to install proxmox master node on the raptor ( 2*150 gb ) and to add another raid partition to store a new data storage VM ?
So it will be something like this :

Proxmox master node ( 150 gb * 2 RAID ) -------------- some vm's

Another raid partition for 1 VM only ( 1 TB * 2 RAID ) can we see this vm on the web interface...


Is it the best configuration with my hardware ? ( 2 * 150 Gb raptor + 2 * 1 Tb WD with Raid card )


Thx !

 

[tom]

yes, it´s possible. search the forum (use terms like 'second hard disk') for explanations, its already discussed several times.

 

[guedouarj]

Yes it's possible but my main question is about the best practice ?


I mean is it better to put all the vm on 1 partition ( ex : 1TB hard disk ) and to run proxmox on the small hdd ? Or to run everything on the RAID partition ?

I'm looking for performances too but not for all and I know that data storage doesn't need a fast hard disk...


So here is the choice :

4 * 150 GB Raptor in RAID 10 ( or RAID 1, to store everything )

or

2 * 150 GB Raptor ( RAID 1, to store important vms like applications server ) + 2 * 1TB WD ( in RAID 1 too, to store data storage vm ) ---> of course on the same raid controller


This is my question

 

[tom]

depends on your needs and budget. raid10 is always faster and raptors are also faster than 1TB WD drives.

 

[guedouarj]

If I put proxmox on the RAID raptor partition and store the data storage vm on the other hard disk, I will lose some perfs ? Because there is a latency between the master node ( proxmox ) and the other hard disk partition no ?

 

[tom]

you are talking about several Proxmox VE nodes in a cluster?

 

[guedouarj]

No, I'm not talking bout clusters, Im talking about 1 proxmox server with several vm but in different physical hard disks...

 

[tom]

ok, but I do do not get the question.

e.g. if you want full speed, go for raptors in raid10.

 

[udo]

Hi,
i have good experiences with following setup (handmade, but based on a normal PVE-installation):
System and backup-partition on a raid-1 (2*2TB Sata)
VM-Storage for VMs (and DRBD...) on a raid-10 with 4 * SAS-Drives

The different between SAS to SATA are huge (with a fast controller) - for more speed use 6 SAS instead of 4.
Raid-1 for VMs is not very fast.

Udo

 

[guedouarj]

So putting the VM in another partition is not good ? It's better to store them on the same system partition ? ( proxmox )

 

[tom]

So putting the VM in another partition is not good ? It's better to store them on the same system partition ? ( proxmox )

I suggest you make yourself familiar with the difference of RAID Level and our LVM partitioning (root/data/swap).

Or just use RAID10 as this is the recommended setup.

 

[guedouarj]

Yes I already did some search about it, but for example, taking this scenario :

system local 2*150 gb raptor - LVM pve

I will create another LVM for the second partition to store the VM so : 2 * 1 TB WD - LVM datas

As the VM are stored in another partition ( and another hdd ), I will lose some performences ? because the VM are stored in simple hdd ( WD ones ) but the system ( pve local ) is stored on the raptor HDD, so ?

The question is : If the main partition is stored on fast HDD, is it ok to have the best perfs ? even if the VM are stored in slow HDD ? No lag or no latency ?



Thx !

 

[udo]

Yes I already did some search about it, but for example, taking this scenario :

system local 2*150 gb raptor - LVM pve

I will create another LVM for the second partition to store the VM so : 2 * 1 TB WD - LVM datas

As the VM are stored in another partition ( and another hdd ), I will lose some performences ? because the VM are stored in simple hdd ( WD ones ) but the system ( pve local ) is stored on the raptor HDD, so ?

The question is : If the main partition is stored on fast HDD, is it ok to have the best perfs ? even if the VM are stored in slow HDD ? No lag or no latency ?



Thx !

Hi,
the best perfomance you need there where the VM-disks/files are!
If you use kvm with lvm-storage it's enough if this lvm-storage is fast. If you also use OpenVZ-VMs (they use local storage) then also the logical volume pve-data should also fast.

You don't need top performance for the system. But all this things are in my posting before (system raid1, lvm-storage raid10).

Udo

 

[guedouarj]

Then it's better to store the main VM on the 2*150gb raptor hdd ( a specific lvm ) and the data storage on the 2* 1 TB WD ( another lvm ), I will always use the KVM as I have a i7 cpu and a lot of ram ( 16 go ).

Thanks for your comments !

 

[lou1z]

i think the point here is the difference between raid 1 and raid 10.
with the underlying hardware, you will always get a faster write on a raid 10 than a raid 1 (due to striping) and you can't do a raid 10 with 2x hd.
so 4x hd in a raid 10 for everything will have faster writes than 2x hd (raid 1, system drive) & 2x hd (raid1, vm drive)

your raid card could probably do raid 0 ie 2x hd (raid 0, system) & 2x hd (raid 0,vm drive) but i wouldn't recommend it.

and if going for SAS, watch out for the nearline SAS as it's only a SATA drive with a SAS bus, not on a par with 10k or 15k SAS drives.

as stated, it depends on what your needs are as performance comes with a price. i've seen an exsi server perform quite well with 4 x samsung F3 SATA's in a raid 10 for 4-6 vms.

 

[maxprox]

i think the point here is the difference between raid 1 and raid 10.
...
as stated, it depends on what your needs are as performance comes with a price. i've seen an exsi server perform quite well with 4 x samsung F3 SATA's in a raid 10 for 4-6 vms.

Hello,
I hope it is okay to pick the thread up again?
As you say, I now have a system with 4 x 1TB (WD-RE4) in RAID 10 => 2 TB
Now I want a linux file server (maybe sme-server) virtualization. I want to work with two disks (two VM Storages) for the system:

1: maybe 20 GB for the SME-Server installation, as a normal virtual machine (for example/var/lib/vz/images/102/vm-102-disk-1.qcow2)
2: maybe 300 GB for the shared user files (in the SME-Server mounted as /home)

My question:
How do I solve point two at best, what is the best practic?
Like point one as a normal lokal Storage? New Disk Storage - local (dir) with Image format qcow2
Or it would be a better solution to shrink the main LV /dev/pve/data to make a new LV, which I then put to the SME server available?
regards
maxprox

 

[udo]

Hello,
I hope it is okay to pick the thread up again?
As you say, I now have a system with 4 x 1TB (WD-RE4) in RAID 10 => 2 TB
Now I want a linux file server (maybe sme-server) virtualization. I want to work with two disks (two VM Storages) for the system:

1: maybe 20 GB for the SME-Server installation, as a normal virtual machine (for example/var/lib/vz/images/102/vm-102-disk-1.qcow2)
2: maybe 300 GB for the shared user files (in the SME-Server mounted as /home)

My question:
How do I solve point two at best, what is the best practic?
Like point one as a normal lokal Storage? New Disk Storage - local (dir) with Image format qcow2
Or it would be a better solution to shrink the main LV /dev/pve/data to make a new LV, which I then put to the SME server available?
regards
maxprox

Hi,
if you don't have shared storage i prefer the simple way: use local pve-data with diskimages in raw-format. If your 300GB-partition will be heavily used, look for enough free space in the VG for backup.

Udo

 

[maxprox]

Hi,
if you don't have shared storage i prefer the simple way: use local pve-data with diskimages in raw-format. If your 300GB-partition will be heavily used, look for enough free space in the VG for backup.
Udo

Hello Udo,
thank you for the answer.

Okay, and yes it "will be heavily used" ...
And raw has a better performance than qcow2?
So far, I've always used qcow2, because the book by Robert Warnke "qemu-kvm and libvirt":
1: because of the sparce file with only use the currently used memory size -
is that also the same with raw diskimages and ext3?
2: simply because I've read that this is the newest (=best?) format ;-)

but I'll try raw
Regards,
maxprox

 

[udo]

Hello Udo,
thank you for the answer.

Okay, and yes it "will be heavily used" ...
And raw has a better performance than qcow2?
So far, I've always used qcow2, because the book by Robert Warnke "qemu-kvm and libvirt":
1: because of the sparce file with only use the currently used memory size -
is that also the same with raw diskimages and ext3?
2: simply because I've read that this is the newest (=best?) format ;-)

but I'll try raw
Regards,
maxprox

Hi maxprox,
i had one time trouble with an qcow2-disk. After converting to raw no trouble anymore.
With raw you have one layer less between guest-os and the harddisk.
Of course you have some nice features with qcow2 (snapshot) but speed and reliability are very good with raw. And i use allways raw like you allways use qcow2 ;-)

Udo

 

[maxprox]

Hi maxprox,
i had one time trouble with an qcow2-disk. After converting to raw no trouble anymore.
With raw you have one layer less between guest-os and the harddisk.
Of course you have some nice features with qcow2 (snapshot) but speed and reliability are very good with raw. And i use allways raw like you allways use qcow2 ;-)
Udo

Hi Udo,

okay,
In this case, I will test raw, because there are only user data that I safe with normal backup program (backuppc) ...
That's it - thank you

maxprox