Re: [ovirt-users] effectiveness of "discard=unmap"

2018-02-10 Thread Idan Shaby
Hi Matthias,

When the guest executes a discard call of any variation (fstrim,
blkdiscard, etc.), the underlying thinly provisioned LUN is the one that
changes -  it returns the unused blocks to the storage array and gets
Therefore, no change is visible to the guest OS.
If you want to check what has changed, go to the storage array and check
what's the size of the underlying thinly provisioned LUN before and after
the discard call.

The answer for your question and some more information can be found in the
feature page [1] (needs a bit of an update, but most of it is still
If you got any further questions, please don't hesitate to ask.


[1] Pass discard from guest to underlying storage -

On Thu, Feb 8, 2018 at 2:08 PM, Matthias Leopold <> wrote:

> Hi,
> i'm sorry to bother you again with my ignorance of the DISCARD feature for
> block devices in general.
> after finding several ways to enable "discard=unmap" for oVirt disks (via
> standard GUI option for iSCSI disks or via "diskunmap" custom property for
> Cinder disks) i wanted to check in the guest for the effectiveness of this
> feature. to my surprise i couldn't find a difference between Linux guests
> with and without "discard=unmap" enabled in the VM. "lsblk -D" reports the
> same in both cases and also fstrim/blkdiscard commands appear to work with
> no difference. Why is this? Do i have to look at the underlying storage to
> find out what really happens? Shouldn't this be visible in the guest OS?
> thx
> matthias
> ___
> Users mailing list
Users mailing list

[ovirt-users] Using network assigned to VM on CentOS host?

2018-02-10 Thread Wesley Stewart
This might be a stupid question.  But I am testing out a 10Gb network
directly connected to my Freenas box using a Cat6 crossover cable.

I setup the connection (on device eno4) and called the network "Crossover"
in oVirt.

I dont have DHCP on this, but I can easy assign VMs a NIC on the
"Crossover" network, assign them an ip address (10.10.10.x) and everything
works fine.  But I was curious about doing this for the CentOS host as
well.  I want to test out hosting VM's on the NFS share over the 10Gb
network but I wasn't quite sure how to do this without breaking other
connections and I did not want to do anything incorrectly.

I appreciate your feedback!  I apologize if this  is a stupid question.

Running oVirt 4.1.8 on CentOS 7.4
Users mailing list

Re: [ovirt-users] Issue with 4.2.1 RC and SSL

2018-02-10 Thread ~Stack~
On 02/08/2018 06:42 AM, Petr Kotas wrote:
> Hi Stack,

Greetings Petr

> have you tried it on other linux distributions? Scientific is not
> officially supported.

No, but SL isn't really any different than CentOS. If anything, we've
found it adheres closer to RH than CentOS does.

> My guess based on your log is there are somewhere missing certificates,
> maybe different path?.
> You can check the paths by the documentation:
> Hope this helps.

Thanks for the suggestion. It took a while but we dug into it and I
*think* the problem was because I may have over-written the wrong cert
file in one of my steps. I'm only about 80% certain of that, but it
seems to match what we found when we were digging through the log files.

We decided to just start from scratch and my coworker watched and
confirmed every step. It works! No problems at all this time. Further
evidence that I goofed _something_ up the first time.

Thank you for the suggestion!

Description: OpenPGP digital signature
Users mailing list

Re: [ovirt-users] Info about windows guest performance

2018-02-10 Thread Gianluca Cecchi
On Fri, Feb 9, 2018 at 4:32 PM, Gianluca Cecchi 

> If I edit the VM, in general settings I see "Other OS" as operating system.
> In General subtab after selecting the VM  in "Virtual Machines" tab I
> again see "Other OS" in "Operating System" and the field "Origin" filled
> with the value "VMware"
> During virt-v2v it seems it was recognized as Windows 2008 though...
> libguestfs: trace: v2v: hivex_value_utf8 = "Windows Server 2008 R2
> Enterprise"
> libguestfs: trace: v2v: hivex_value_key 11809408
> I can send all the log if it can help.
> Thanks,
> Gianluca

So it seems it has been a problem with virt-v2v conversion, because if I
shutdown the VM and set it to Windows 2008 R2 x86_64 and optimized for
server and I run it, I get this flag for the cpu:

-cpu Westmere,vmx=on,hv_time,hv_relaxed,hv_vapic,hv_spinlocks=0x1fff

BTW: what are the other flags for:


Complete command is:

-name guest=testmig,debug-threads=on
-machine pc-i440fx-rhel7.3.0,accel=kvm,usb=off,dump-guest-core=off
-cpu Westmere,vmx=on,hv_time,hv_relaxed,hv_vapic,hv_spinlocks=0x1fff
-m size=4194304k,slots=16,maxmem=16777216k
-realtime mlock=off
-smp 2,maxcpus=16,sockets=16,cores=1,threads=1
-numa node,nodeid=0,cpus=0-1,mem=4096
-uuid XXX
-smbios type=1,manufacturer=oVirt,product=oVirt
-mon chardev=charmonitor,id=monitor,mode=control
-rtc base=2018-02-10T18:32:22,driftfix=slew
-global kvm-pit.lost_tick_policy=delay
-boot strict=on
-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2
-device virtio-scsi-pci,id=scsi0,bus=pci.0,addr=0x5
-device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x4
-drive if=none,id=drive-ide0-1-0,readonly=on
-device ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0
-netdev tap,fd=30,id=hostnet0
-chardev spicevmc,id=charchannel2,name=vdagent
-msg timestamp=on

Users mailing list

Re: [ovirt-users] Maximum time node can be offline.

2018-02-10 Thread Thomas Letherby
That's exactly what I needed to know, thanks all.

I'll schedule a script for the nodes to reboot and patch once every week or
two and then I can let it run without me needing to worry about it.


On Fri, Feb 9, 2018, 2:26 AM Martin Sivak  wrote:

> Hi,
> the hosts are almost stateless and we set up most of what is needed
> during activation. Hosted engine has some configuration stored
> locally, but that is just the path to the storage domain.
> I think you should be fine unless you change the network topology
> significantly. I would also install security updates once in while.
> We can even shut down the hosts for you when you configure two cluster
> scheduling properties: EnableAutomaticPM and HostsInReserve.
> HostsInReserve should be at least 1 though. It behaves like this, as
> long as the reserve host is empty, we shut down all the other empty
> hosts. And we boot another host once a VM does not fit on other used
> hosts and is places on the running reserve host. That would save you
> the power of just one host, but it would still be highly available (if
> hosted engine and storage allows that too).
> Bear in mind that single host cluster is not highly available at all.
> Best regards
> Martin Sivak
> On Fri, Feb 9, 2018 at 8:25 AM, Gianluca Cecchi
>  wrote:
> > On Fri, Feb 9, 2018 at 2:30 AM, Thomas Letherby 
> wrote:
> >>
> >> Thanks, that answers my follow up question! :)
> >>
> >> My concern is that I could have a host off-line for a month say, is that
> >> going to cause any issues?
> >>
> >> Thanks,
> >>
> >> Thomas
> >>
> >
> > I think that if in the mean time you don't make any configuration changes
> > and you don't update anything, there is no reason to have problems.
> > In case of changes done, it could depend on what they are: are you
> thinking
> > about any particular scenario?
> >
> >
> > ___
> > Users mailing list
> >
> >
> >
Users mailing list