I don't see any other bottleneck. CPUs are quite idle. Seems that the load
is mostly due to high latency on IO.

Reading further the gluster docs:

https://github.com/gluster/glusterfs-specs/blob/master/done/GlusterFS%203.5/libgfapi%20with%20qemu%20libvirt.md

I see that I am missing the following options:

/etc/glusterfs/glusterd.vol :
option rpc-auth-allow-insecure on

gluster volume set vms gluster server.allow-insecure on

It says that the above allow qemu to use libgfapi.
When checking the VM XML, I don't see any gluster protocol at the disk
drive:

<disk type='file' device='disk' snapshot='no'>
      <driver name='qemu' type='raw' cache='none' error_policy='stop'
io='threads'/>
      <source
file='/rhev/data-center/00000001-0001-0001-0001-000000000311/94741028-e765-4300-a618-c3eeb7dbb7c8/images/222a1312-5efa-4731-8914-9a9d24dccba5/d691e6b3-c8e7-4820-9042-555d30c8a21b'/>
      <target dev='sda' bus='scsi'/>
      <serial>222a1312-5efa-4731-8914-9a9d24dccba5</serial>
      <boot order='1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>



While at gluster docs it mentions the below type of disk:

<disk type='network' device='disk'>
       <driver name='qemu' type='raw' cache='none'/>
       <source protocol='gluster' name='distrepvol/vm3.img'>
            <host name='10.70.37.106' port='24007'/>
        </source>
       <target dev='vda' bus='virtio'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04'
function='0x0'/>
    </disk>


Does the above indicate that ovirt/qemu is not using libgfapi but FUSE only?
This could be the reason of such slow perf.


On Thu, Sep 7, 2017 at 1:47 PM, Yaniv Kaul <yk...@redhat.com> wrote:

>
>
> On Thu, Sep 7, 2017 at 12:52 PM, Abi Askushi <rightkickt...@gmail.com>
> wrote:
>
>>
>>
>> On Thu, Sep 7, 2017 at 10:30 AM, Yaniv Kaul <yk...@redhat.com> wrote:
>>
>>>
>>>
>>> On Thu, Sep 7, 2017 at 10:06 AM, Yaniv Kaul <yk...@redhat.com> wrote:
>>>
>>>>
>>>>
>>>> On Wed, Sep 6, 2017 at 6:08 PM, Abi Askushi <rightkickt...@gmail.com>
>>>> wrote:
>>>>
>>>>> For a first idea I use:
>>>>>
>>>>> dd if=/dev/zero of=testfile bs=1GB count=1
>>>>>
>>>>
>>>> This is an incorrect way to test performance, for various reasons:
>>>> 1. You are not using oflag=direct , thus not using DirectIO, but using
>>>> cache.
>>>> 2. It's unrealistic - it is very uncommon to write large blocks of
>>>> zeros (sometimes during FS creation or wiping). Certainly not 1GB
>>>> 3. It is a single thread of IO - again, unrealistic for VM's IO.
>>>>
>>>> I forgot to mention that I include oflag=direct in my tests. I agree
>> though that dd is not the correct way to test, hence I mentioned I just use
>> it to get a first feel. More tests are done within the VM benchmarking its
>> disk IO (with tools like IOmeter).
>>
>> I suggest using fio and such. See https://github.com/pcuzner/fio-tools
>>>> for example.
>>>>
>>> Do you have any recommended config file to use for VM workload?
>>
>
> Desktops and Servers VMs behave quite differently, so not really. But the
> 70/30 job is typically a good baseline.
>
>
>>
>>
>>>>
>>>>>
>>>>> When testing on the gluster mount point using above command I hardly
>>>>> get 10MB/s. (On the same time the network traffic hardly reaches 100Mbit).
>>>>>
>>>>> When testing our of the gluster (for example at /root) I get 600 -
>>>>> 700MB/s.
>>>>>
>>>>
>>>> That's very fast - from 4 disks doing RAID5? Impressive (unless you use
>>>> caching!). Are those HDDs or SSDs/NVMe?
>>>>
>>>>
>>> These are SAS disks. But there is also a RAID controller with 1GB cache.
>>
>>
>>>>> When I mount the gluster volume with NFS and test on it I get 90 - 100
>>>>> MB/s, (almost 10x from gluster results) which is the max I can get
>>>>> considering I have only 1 Gbit network for the storage.
>>>>>
>>>>> Also, when using glusterfs the general VM performance is very poor and
>>>>> disk write benchmarks show that is it at least 4 times slower then when 
>>>>> the
>>>>> VM is hosted on the same data store when NFS mounted.
>>>>>
>>>>> I don't know why I hitting such a significant performance penalty, and
>>>>> every possible tweak that I was able to find out there did not make any
>>>>> difference on the performance.
>>>>>
>>>>> The hardware I am using is pretty decent for the purposes intended:
>>>>> 3 nodes, each node having with 32 MB of RAM, 16 physical CPU cores, 2
>>>>> TB of storage in RAID5 (4 disks), of which 1.5 TB are sliced for the data
>>>>> store of ovirt where VMs are stored.
>>>>>
>>>>
>>> I forgot to ask why are you using RAID 5 with 4 disks and not RAID 10?
>>> Same usable capacity, higher performance, same protection and faster
>>> recovery, I believe.
>>>
>> Correction: there are 5 disks of 600GB each. The main reason going with
>> RAID 5 was the capacity. With RAID 10 I can use only 4 of them and get only
>> 1.1 TB usable, with RAID 5 I get 2.2 TB usable. I agree going with RAID 10
>> (+ one additional drive to go with 6 drives) would be better but this is
>> what I have now.
>>
>> Y.
>>>
>>>
>>>> You have not mentioned your NIC speeds. Please ensure all work well,
>>>> with 10g.
>>>> Is the network dedicated for Gluster traffic? How are they connected?
>>>>
>>>>
>>> I have mentioned that I have 1 Gbit dedicated for the storage. A
>> different network is used for this and a dedicated 1Gbit switch. The
>> throughput has been confirmed between all nodes with iperf.
>>
>
> Oh.... With 1Gb, you can't get more than 100+MBps...
>
>
>> I know 10Gbit would be better, but when using native gluster at ovirt the
>> network pipe was hardly reaching 100Mbps thus the bottleneck was gluster
>> and not the network. If I can saturate 1Gbit and I still have performance
>> issues then I may think to go with 10Gbit. With NFS on top gluster I see
>> traffic reaching 800Mbit when testing with dd which is much better.
>>
>
> Agreed. Do you see the bottleneck elsewhere? CPU?
>
>
>>
>>
>>>>> The gluster configuration is the following:
>>>>>
>>>>
>>>> Which version of Gluster are you using?
>>>>
>>>>
>>> The version is  3.8.12
>>
>
> I think it's a very old release (near end of life?). I warmly suggest
> 3.10.x or 3.12.
> There are performance improvements (AFAIR) in both.
> Y.
>
>
>>
>>>>> Volume Name: vms
>>>>> Type: Replicate
>>>>> Volume ID: 4513340d-7919-498b-bfe0-d836b5cea40b
>>>>> Status: Started
>>>>> Snapshot Count: 0
>>>>> Number of Bricks: 1 x (2 + 1) = 3
>>>>> Transport-type: tcp
>>>>> Bricks:
>>>>> Brick1: gluster0:/gluster/vms/brick
>>>>> Brick2: gluster1:/gluster/vms/brick
>>>>> Brick3: gluster2:/gluster/vms/brick (arbiter)
>>>>> Options Reconfigured:
>>>>> nfs.export-volumes: on
>>>>> nfs.disable: off
>>>>> performance.readdir-ahead: on
>>>>> transport.address-family: inet
>>>>> performance.quick-read: off
>>>>> performance.read-ahead: off
>>>>> performance.io-cache: off
>>>>> performance.stat-prefetch: on
>>>>>
>>>>
>>>> I think this should be off.
>>>>
>>>>
>>>>> performance.low-prio-threads: 32
>>>>> network.remote-dio: off
>>>>>
>>>>
>>>> I think this should be enabled.
>>>>
>>>>
>>>>> cluster.eager-lock: off
>>>>> cluster.quorum-type: auto
>>>>> cluster.server-quorum-type: server
>>>>> cluster.data-self-heal-algorithm: full
>>>>> cluster.locking-scheme: granular
>>>>> cluster.shd-max-threads: 8
>>>>> cluster.shd-wait-qlength: 10000
>>>>> features.shard: on
>>>>> user.cifs: off
>>>>> storage.owner-uid: 36
>>>>> storage.owner-gid: 36
>>>>> network.ping-timeout: 30
>>>>> performance.strict-o-direct: on
>>>>> cluster.granular-entry-heal: enable
>>>>> features.shard-block-size: 64MB
>>>>>
>>>>
>>>> I'm not sure if this should not be 512MB.  I don't remember the last
>>>> resolution on this.
>>>> Y.
>>>>
>>>>
>>>>> performance.client-io-threads: on
>>>>> client.event-threads: 4
>>>>> server.event-threads: 4
>>>>> performance.write-behind-window-size: 4MB
>>>>> performance.cache-size: 1GB
>>>>>
>>>>> I have been playing with all above with very little difference on
>> performance I was getting.
>>
>> In case I can provide any other details let me know.
>>>>>
>>>>
>>>> What is your tuned profile?
>>>>
>>>>
>>> the tuned profile is virtual-host
>>
>> At the moment I already switched to gluster based NFS but I have a
>>>>> similar setup with 2 nodes  where the data store is mounted through 
>>>>> gluster
>>>>> (and again relatively good hardware) where I might check any tweaks or
>>>>> improvements on this setup.
>>>>>
>>>>> Thanx
>>>>>
>>>>>
>>>>> On Wed, Sep 6, 2017 at 5:32 PM, Yaniv Kaul <yk...@redhat.com> wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> On Wed, Sep 6, 2017 at 3:32 PM, Abi Askushi <rightkickt...@gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Hi All,
>>>>>>>
>>>>>>> I've playing with ovirt self hosted engine setup and I even use it
>>>>>>> to production for several VM. The setup I have is 3 server with gluster
>>>>>>> storage in replica 2+1 (1 arbiter).
>>>>>>> The data storage domain where VMs are stored is mounted with gluster
>>>>>>> through ovirt. The performance I get for the VMs is very low and I was
>>>>>>> thinking to switch and mount the same storage through NFS instead of
>>>>>>> glusterfs.
>>>>>>>
>>>>>>
>>>>>> I don't see how it'll improve performance.
>>>>>> I suggest you share the gluster configuration (as well as the storage
>>>>>> HW) so we can understand why the performance is low.
>>>>>> Y.
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> The only think I am hesitant is how can I ensure high availability
>>>>>>> of the storage when I loose one server? I was thinking to have at
>>>>>>> /etc/hosts sth like below:
>>>>>>>
>>>>>>> 10.100.100.1 nfsmount
>>>>>>> 10.100.100.2 nfsmount
>>>>>>> 10.100.100.3 nfsmount
>>>>>>>
>>>>>>> then use nfsmount as the server name when adding this domain through
>>>>>>> ovirt GUI.
>>>>>>> Are there any other more elegant solutions? What do you do for such
>>>>>>> cases?
>>>>>>> Note: gluster has the back-vol-file option which provides a lean way
>>>>>>> to have redundancy on the mount point and I am using this when mounting
>>>>>>> with glusterfs.
>>>>>>>
>>>>>>> Thanx
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Users mailing list
>>>>>>> Users@ovirt.org
>>>>>>> http://lists.ovirt.org/mailman/listinfo/users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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