What hardware for PVE ? (IO delay ...)

[ledufakademy]

Always having IODelays and again and again.(14Tb of sas hdd, megaraid hardware raid)
Which hardware is enough to work with Proxmox ?

=> 60 mn restoring 64Gb LXC, IO delay : 38% ... weird and painfull for all other VM ... freezing ...!)
Last update (7.3)

48 x Intel(R) Xeon(R) CPU E5-2697 v2 @ 2.70GHz (2 Sockets) (supermicro)
128GB
16TB , raid 5 , megaraid, 4TB sas HDD 15K, => LVM-THIN
(proxmox OS on two 128GB SSD in ZFS mirror)



Totally freeze some VM ... Awesome !

 

[Dunuin]

Raid5 is a terrible idea for a VM/LXC storage as IOPS won't scale with the number of disks. So no matter if you use 3 or 100 HDDs, IOPS performance will only be as fast as a single HDD. With a raid10 it would at least scale with half the number of disks.
And HDDs in general are a bad choice to store VMs, as these primarily need a good IOPS performance and HDDs are really horrible at that.

So for best performance Enterprise grade SSDs in a raid10 would be the best choice. And if you still don't want to use enterprise SSDs, atleast run those HDDs in a raid10 setup.

 

[hkais]

most important details are missing, the IO during normal operation

As written by Dunuin, RAID5 is great for reading... On writing it depends on the quality of controller how well it can "push back" the IO load for the disks to optimize access.

BUT
you can limit bandwidth on your disk on the VM you're restoring. E.g. try 5MB/s and increase stepwise by 5MB to see how much "disk load" oyur system can eat before getting into saturation.

BUT2
get faster disks, e.g. SSDs
restore to SSDs and move from SSD to HDD to reduce downtime