Let me explain them case by case, I hope it answers your question :-)

First Round:

Migrate VM-1 from Node84 to Node85 -> Migration cancelled because Host does not 
have enough capacity for vm.

CloudStack started the VM on the source host (Node84)



Second Round:

Deploy 4GB ram on Node84 -> Unsuccessful, unable to create a deployment for VM 
instance.

CloudStack created the VM in error state. The VM is not usable and I can only 
expunge it.



Third Round:

Deploy 4GB (without specifying the host id) -> Unsuccessful, unable to create a 
deployment for VM instance

The result was the same as the second round, CloudStack created the VM in error 
state. The VM is not usable and I can only expunge it.





------- Original Message -------
On Friday, March 31st, 2023 at 8:55 AM, jordan j <[email protected]> wrote:


> 

> 

> Thank you Sina!
> 

> By unsuccessful do you mean that CS allows the operation but it gets
> performed unsuccessfully (hypervisor create task fails)? Or does CS just
> refuse the operation ?
> 

> Regards,
> Jordan
> 

> On Thu, Mar 30, 2023 at 7:12 PM Sina Kashipazha
> [email protected] wrote:
> 

> > Hey Jordan,
> > 

> > It seems to be a race condition, I ran small scenario which failed. This
> > was my setup:
> > 

> > Node:
> > Node84: 8GB ram available, 4GB of that allocated to the VM-1
> > Node85: 8GB ram, NO VMs.{}
> > 

> > The following actions run at the same time using cmk:
> > 

> > Deploy 4GB ram on Node84
> > Migrate VM-1 from Node84 to Node85
> > Deploy 4GB (without specifying the host id)
> > 

> > First Round:
> > Deploy 4GB ram on Node84 -> Successful
> > Migrate VM-1 from Node84 to Node85 -> Migration cancelled because Host
> > does not have enough capacity for vm
> > Deploy 4GB (without specifying the host id) -> Successful
> > 

> > Second Round:
> > Deploy 4GB ram on Node84 -> Unsuccessful, unable to create a deployment
> > for VM instance
> > Migrate VM-1 from Node84 to Node85 -> Successful
> > Deploy 4GB (without specifying the host id) -> Successful
> > 

> > Third Round:
> > Deploy 4GB ram on Node84 -> Successful
> > Migrate VM-1 from Node84 to Node85 -> Successful
> > Deploy 4GB (without specifying the host id) -> Unsuccessful, unable to
> > create a deployment for VM instance
> > 

> > Fourth Round:
> > Same as first round.
> > 

> > Kind regards,
> > Sina
> > 

> > ------- Original Message -------
> > On Thursday, March 30th, 2023 at 2:24 PM, jordan j [email protected]
> > wrote:
> > 

> > > Hey everyone,
> > > 

> > > This week we are doing performance tests on the environment and we
> > > noticed
> > > something weird.
> > > 

> > > Setup:
> > > - Cloudstack 4.17.2 + XCP-NG advanced network with SG.
> > > - zone with 30 XCP hosts (in 30 clusters) each with 100 GB ram and 100
> > > cores
> > > - There is one compute offering with user dispersing planner. The
> > > offering
> > > has a local storage bound (no shared storage on servers) .
> > > 

> > > Using terraform we tried to deploy 60 instances, 49 GB of ram each and 50
> > > cores.
> > > Some of them were not deployed (about 5).
> > > Running the same task again and again eventually makes the failed
> > > instances
> > > be deployed eventually.
> > > 

> > > Wondering why this happens... looking at the logs i found out that the
> > > VMs
> > > fail because of not enough memory on the XCPs. Error comes from XAPI and
> > > not from Cloudstack which makes me conclude that Cloudstack allows the
> > > task
> > > but for some reason the scheduler/planner does not compute the memory
> > > resource properly. I wonder if there is a race condition problem where 2
> > > instances are assigned the same host server and what happens is sa both
> > > get
> > > created there is memory just for one of them.
> > > 

> > > Tried to simulate the issue by simultaneously creating instances from the
> > > GUI on a group of 2 servers but it seems GUI-created-instances even if
> > > launched together are executed in order so the scheduler detects when
> > > there
> > > is no more RAM and the rest of the processes are stopped.
> > > 

> > > Has anyone experienced such a problem?
> > > 

> > > Regards,
> > > Jordan

Attachment: signature.asc
Description: OpenPGP digital signature

Reply via email to