subject:"\[ovirt\-users\] Re\: oVirt \+ TrueNAS\: Unable to create iSCSI domain \- I am missing something obvious"

[ovirt-users] Re: oVirt + TrueNAS: Unable to create iSCSI domain - I am missing something obvious

2023-01-19 Thread None via Users

FYI the fix is to check the "Disabled Physical Block Size Reporting" box in the 
extent window. Note in testing this I had to delete the extent and create a new 
one, toggling the switch on and then restarting the iscsi service didn't seem 
to do it, maybe the client cached something.
___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: 
https://www.ovirt.org/community/about/community-guidelines/
List Archives: 
https://lists.ovirt.org/archives/list/users@ovirt.org/message/W5XSBQD6Z6X4HOHIQC2EVBBL6AJRXNDW/

[ovirt-users] Re: oVirt + TrueNAS: Unable to create iSCSI domain - I am missing something obvious

2022-03-03 Thread David Johnson

I'm looking at a 50 TB system right now, and we have had discussions about
petabyte systems.

*David Johnson*
*Director of Development, Maxis Technology*
844.696.2947 ext 702 (o) | 479.531.3590 (c)




*Follow us:*  


On Thu, Mar 3, 2022 at 1:45 PM Strahil Nikolov 
wrote:

> How much is 'massive amounts of data' ?
>
> Best Regards,
> Strahil Nikolov
>
> On Thu, Mar 3, 2022 at 15:58, David Johnson
>  wrote:
> ___
> Users mailing list -- users@ovirt.org
> To unsubscribe send an email to users-le...@ovirt.org
> Privacy Statement: https://www.ovirt.org/privacy-policy.html
> oVirt Code of Conduct:
> https://www.ovirt.org/community/about/community-guidelines/
> List Archives:
> https://lists.ovirt.org/archives/list/users@ovirt.org/message/TZHWXMG45F2IMAM3WCBLUA2W5L5MXHHH/
>
>
___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: 
https://www.ovirt.org/community/about/community-guidelines/
List Archives: 
https://lists.ovirt.org/archives/list/users@ovirt.org/message/5PHATYFL6EDFNQPIH4J7MTEK7NHZAG3M/

[ovirt-users] Re: oVirt + TrueNAS: Unable to create iSCSI domain - I am missing something obvious

2022-03-03 Thread Strahil Nikolov via Users

How much is 'massive amounts of data' ?
Best Regards,Strahil Nikolov
 
 
  On Thu, Mar 3, 2022 at 15:58, David Johnson 
wrote:   ___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: 
https://www.ovirt.org/community/about/community-guidelines/
List Archives: 
https://lists.ovirt.org/archives/list/users@ovirt.org/message/TZHWXMG45F2IMAM3WCBLUA2W5L5MXHHH/
  
___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: 
https://www.ovirt.org/community/about/community-guidelines/
List Archives: 
https://lists.ovirt.org/archives/list/users@ovirt.org/message/2ACAKV7C4SUYOGMPW65PSC2JPYET4GS5/

[ovirt-users] Re: oVirt + TrueNAS: Unable to create iSCSI domain - I am missing something obvious

2022-03-03 Thread David Johnson

Thank you both. This is certainly good information.

If I'm going to jump to a different backing store, now it's the time to do
it. But I'm not going to jump simply for the sake of jumping.

The nfs issue was reproduced at redhat on a storage appliance other than
truenas (QNAP I believe), so I am leaning away from nfs, at least until I
see something that indicates this has been fixed.

As I read these notes, and others on a TrueNAS forum, it is beginning to
look like truenas may not necessarily be the best choice for a backing
store for ovirt in my environment. TrueNAS iSCSI (more specifically the
underlying ZFS) struggles with heavy write usage with small block sizes,
and the entire intent of my cluster is to write massive amounts of data as
fast as possible.

My storage server is a superMicro. Today it runs TrueNAS, but I can change
that if the benefit is there. I note that OpenStack prefers Cinder.

More research coming ...

On Wed, Mar 2, 2022, 9:28 PM Vinícius Ferrão 
wrote:

> David do yourself a favor a move away from NFS on TrueNAS for VM hosting.
>
> As a personal experience hosting VMs on NFS may cause your entire
> infrastructure to be down if you change something on TrueNAS, even adding a
> new NFS share may trigger a NFS server restart and suddenly all your VMs
> will be trashed. Emphasis on _may_.
>
> I’ve been using the product since FreeNAS 8, which was 2012 and that’s
> observed behavior.
>
> Also oVirt has its quirks with iSCSI, mainly on MPIO (Multipath I/O) but
> as for the combination with TrueNAS just stick with iSCSI.
>
> Sent from my iPhone
>
> On 3 Mar 2022, at 00:02, David Johnson 
> wrote:
>
> 
> The cluster is on nfs today, with 500gb NVME SiLOG. Under heavy IO the
> vm's are thrown into paused state instead of iowait. A prior email chain
> identified a code error in qemu, with a repro using nothing more than DD to
> set 2 gb on the virtual disk to 0's .
>
> Since the point of the system is to handle massive IO workloads, this is
> obviously not acceptable.
>
> If there is a way to make the nfs Mount more robust I'm all for it over
> the headaches that go with managing block io.
>
> On Wed, Mar 2, 2022, 8:46 AM Nir Soffer  wrote:
>
>> On Wed, Mar 2, 2022 at 3:01 PM David Johnson <
>> djohn...@maxistechnology.com> wrote:
>>
>>> Good morning folks, and thank you in advance.
>>>
>>> I am working on migrating my oVirt backing store from NFS to iSCSI.
>>>
>>> *oVirt Environment:*
>>>
>>> oVirt Open Virtualization Manager
>>> Software Version:4.4.4.7-1.el8
>>>
>>> *TrueNAS environment:*
>>>
>>> FreeBSD truenas.local 12.2-RELEASE-p11 75566f060d4(HEAD) TRUENAS amd64
>>>
>>>
>>> The iSCSI share is on a TrueNAS server, exposed to user VDSM and group
>>> 36.
>>>
>>> oVirt sees the targeted share, but is unable to make use of it.
>>>
>>> The latest issue is "Error while executing action New SAN Storage
>>> Domain: Volume Group block size error, please check your Volume Group
>>> configuration, Supported block size is 512 bytes."
>>>
>>> As near as I can tell, oVirt does not support any block size other than
>>> 512 bytes, while TrueNAS's smallest OOB block size is 4k.
>>>
>>
>> This is correct, oVirt does not support 4k block storage.
>>
>>
>>>
>>> I know that oVirt on TrueNAS is a common configuration, so I expect I am
>>> missing something really obvious here, probably a TrueNAS configuration
>>> needed to make TrueNAS work with 512 byte blocks.
>>>
>>> Any advice would be helpful.
>>>
>>
>> You can use NFS exported by TrueNAS. With NFS the underlying block size
>> is hidden
>> since direct I/O on NFS does not perform direct I/O on the server.
>>
>> Another way is to use Managed Block Storage (MBS) - if there a Cinder
>> driver that can manage
>> your storage server, you can use MBS disks with any block size. The block
>> size limit comes from
>> the traditional lvm based storage domain code. When using MBS, you use
>> one LUN per disk, and
>> qemu does not have any issue working with such LUNs.
>>
>> Check with TrueNAS if they support emulating 512 block size of have
>> another way to
>> support clients that do not support 4k storage.
>>
>> Nir
>>
> ___
> Users mailing list -- users@ovirt.org
> To unsubscribe send an email to users-le...@ovirt.org
> Privacy Statement: https://www.ovirt.org/privacy-policy.html
> oVirt Code of Conduct:
> https://www.ovirt.org/community/about/community-guidelines/
> List Archives:
> https://lists.ovirt.org/archives/list/users@ovirt.org/message/6NLGE4Q2ABJ2DEP7MXFRZ3QLQNP37A5V/
>
>
___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: 
https://www.ovirt.org/community/about/community-guidelines/
List Archives: 
https://lists.ovirt.org/archives/list/users@ovirt.org/message/TZHWXMG45F2IMAM3WCBLUA2W5L5MXHHH/

[ovirt-users] Re: oVirt + TrueNAS: Unable to create iSCSI domain - I am missing something obvious

2022-03-02 Thread Vinícius Ferrão via Users

And as a complement for the last message, having 500GB of SLOG is almost
irrelevant.

SLOG isn’t a write cache mechanism, it’s a write offload one. The maximum size
used by SLOG is equal to the maximum transaction group that you could have.

I don’t know the maths to measure this for you, but I do know that a saturated
10GbE link will only generate 8GB of SLOG.

The reason you want to use a bigger device for SLOG is endurance and some
vendors only achieve full performance with bigger devices. It’s not the
capacity you’re looking for.

This information is not easily gathered on the web, but TrueNAS documentation
is getting better, as you could see here:
https://www.truenas.com/docs/references/slog/

Please excuse-me if any information I provided is wrong about SLOG on ZFS. I
don’t think it is but I haven’t rechecked it for a while (maybe 3-5 years).

Sent from my iPhone

On 3 Mar 2022, at 00:28, Vinícius Ferrão wrote:

David do yourself a favor a move away from NFS on TrueNAS for VM hosting.

As a personal experience hosting VMs on NFS may cause your entire
infrastructure to be down if you change something on TrueNAS, even adding a new
NFS share may trigger a NFS server restart and suddenly all your VMs will be
trashed. Emphasis on _may_.

I’ve been using the product since FreeNAS 8, which was 2012 and that’s observed
behavior.

Also oVirt has its quirks with iSCSI, mainly on MPIO (Multipath I/O) but as for
the combination with TrueNAS just stick with iSCSI.

Sent from my iPhone

On 3 Mar 2022, at 00:02, David Johnson wrote:

The cluster is on nfs today, with 500gb NVME SiLOG. Under heavy IO the vm's are
thrown into paused state instead of iowait. A prior email chain identified a
code error in qemu, with a repro using nothing more than DD to set 2 gb on the
virtual disk to 0's .

Since the point of the system is to handle massive IO workloads, this is
obviously not acceptable.

If there is a way to make the nfs Mount more robust I'm all for it over the
headaches that go with managing block io.

On Wed, Mar 2, 2022, 8:46 AM Nir Soffer
mailto:nsof...@redhat.com>> wrote:
On Wed, Mar 2, 2022 at 3:01 PM David Johnson
mailto:djohn...@maxistechnology.com>> wrote:
Good morning folks, and thank you in advance.

I am working on migrating my oVirt backing store from NFS to iSCSI.

oVirt Environment:
oVirt Open Virtualization Manager
Software Version:4.4.4.7-1.el8
TrueNAS environment:
FreeBSD truenas.local 12.2-RELEASE-p11 75566f060d4(HEAD) TRUENAS amd64

The iSCSI share is on a TrueNAS server, exposed to user VDSM and group 36.

oVirt sees the targeted share, but is unable to make use of it.

The latest issue is "Error while executing action New SAN Storage Domain:
Volume Group block size error, please check your Volume Group configuration,
Supported block size is 512 bytes."

As near as I can tell, oVirt does not support any block size other than 512
bytes, while TrueNAS's smallest OOB block size is 4k.

This is correct, oVirt does not support 4k block storage.

I know that oVirt on TrueNAS is a common configuration, so I expect I am
missing something really obvious here, probably a TrueNAS configuration needed
to make TrueNAS work with 512 byte blocks.

Any advice would be helpful.

You can use NFS exported by TrueNAS. With NFS the underlying block size is
hidden
since direct I/O on NFS does not perform direct I/O on the server.

Another way is to use Managed Block Storage (MBS) - if there a Cinder driver
that can manage
your storage server, you can use MBS disks with any block size. The block size
limit comes from
the traditional lvm based storage domain code. When using MBS, you use one LUN
per disk, and
qemu does not have any issue working with such LUNs.

Check with TrueNAS if they support emulating 512 block size of have another way
to
support clients that do not support 4k storage.

Nir
___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct:
https://www.ovirt.org/community/about/community-guidelines/
List Archives:
https://lists.ovirt.org/archives/list/users@ovirt.org/message/6NLGE4Q2ABJ2DEP7MXFRZ3QLQNP37A5V/
___
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-le...@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct:
https://www.ovirt.org/community/about/community-guidelines/
List Archives:
https://lists.ovirt.org/archives/list/users@ovirt.org/message/2FPJSYW6LKWOQISRI26X4REYJSQVWL7E/