Raid5 + Drbd + LVM ; Block size and alignment optimization ?

[gohu]

Hi

I use Proxmox 1.7. I have "not so bad" performances but I think it could be better on hard drives.
Indeed, how can I be sure that stacking various layer of "virtual storage" wont degrade disk performances ?

I think that if block size isn't the same at every level and if block aren't aligned so that you write many block at the Raid5 layer instead of just one on the LVM level.

To that, you can also add the parity computing of the Raid 5 layer.

Does anybody have already thought about it ? What can I do to check theses aspects of my configuration ?

Thank you

Hugo

 

[udo]

Hi

I use Proxmox 1.7. I have "not so bad" performances but I think it could be better on hard drives.
Indeed, how can I be sure that stacking various layer of "virtual storage" wont degrade disk performances ?

I think that if block size isn't the same at every level and if block aren't aligned so that you write many block at the Raid5 layer instead of just one on the LVM level.

To that, you can also add the parity computing of the Raid 5 layer.

Does anybody have already thought about it ? What can I do to check theses aspects of my configuration ?

Thank you

Hugo

Hi,
this was discussed some time ago. See here: http://forum.proxmox.com/threads/2460-Best-RAID-configuration-for-PVE?p=13694#poststop

Udo

 

[gohu]

Thanks, sorry I didn't found this topic