[PVE-User] Ceph RBD image striping

[Alwin Antreich]

Hi Markus,

On 07/06/2016 02:06 PM, Markus Dellermann wrote:
> Hi..
> Am Mittwoch, 6. Juli 2016, 13:56:21 CEST schrieb Alwin Antreich:
>> Hi,
>>
>> On 07/06/2016 09:33 AM, Eneko Lacunza wrote:
>>> Hi,
>>>
>>> El 06/07/16 a las 09:26, Alwin Antreich escribió:
>>>> On 07/06/2016 08:27 AM, Eneko Lacunza wrote:
>>>>> Hi Alwin,
>>>>>
>>>>> In Proxmox Ceph client integration is done using librbd, not krbd.
>>>>> Stripe parameters can't be defined from Proxmox GUI.>> 
>>>> If I understood correctly, this depends, if you add a ceph pool to
>>>> proxmox with the KRBD option enabled or not. I know that these settings
>>>> aren't done through the GUI, as you need to create the image with ceph
>>>> tools manually.> 
>>> Sorry, I didn't recall the "new" krbd checkbox in storage config, never
>>> used that myself. Why are you using it?
>> For LXC it's required, as this maps the rbd image, so it can be mounted by
>> lxc.
>>>>> Why are you changing striping parameters?
>>>>
>>>> We have some write intense tasks to perform and stripping can boost write
>>>> performance. To test this I would like to add such a disk to a VM.
>>>
>>> I would do as follows:
>>> - Create the VM rbd disk from GUI
>>> - Then from CLI, remove rbd volume and recreate with the same name and the
>>> striping parameters you want.
>> That's the way I went, but the disk isn't picked up and the only thing I see
>> is the timeout.
>>> Are you using SSDs for journals?
>>>
>>>
>>> Cheers
>>
>> It is working now, but in the end, I found two different issues. The first
>> one, had to do with the VM I was testing, once I tried the same setup with
>> a different VM it gave me the second issue. Apparently there is a
>> difference between mon_host address list formatting with comma or space
>> between IPs.
>>
>> ==with KRBD==
>> monhost 192.168.4.50,192.168.4.51,192.168.4.52
>> ==w/o KRBD==
>> monhost 192.168.4.50 192.168.4.51 192.168.4.52
>>
> 
> You should use semicolon 

But this gives me the error message, when I try to mount the image. I created a separate email on this to follow up.

Thanks.

> 
> 
> 
>> ==error message==
>> kvm: -drive
>> file=rbd:rbd2/vm-101-disk-1:mon_host=192.168.4.50,192.168.4.51,192.168.4.52:
>> id=admin:auth_supported=cephx:keyring=/etc/pve/priv/ceph/rbd2.keyring,if=non
>> e,id=drive-virtio0,cache=writeback,discard=on,format=raw,aio=threads,detect-
>> zeroes=unmap: Block format 'raw' used by device 'drive-virtio0' doesn't
>> support the option '192.168.4.51'
>>
>> Now, is this a ceph issue or proxmox? I will send a new email to follow up
>> on this separately.
>>
>> Cheers,
>> Alwin
>>
> 
> Markus
> 
>> _______________________________________________
>> pve-user mailing list
>> pve-user at pve.proxmox.com
>> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
> 
> 
> _______________________________________________
> pve-user mailing list
> pve-user at pve.proxmox.com
> http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
> 

Cheers,
Alwin