[pve-devel] iothread

[Alexandre DERUMIER]

>>I have just discovered that when iothread is enabled on a disk this 
>>disk cannot be moved online using move disk. 

>>>just tested from ceph to ceph, with iothread enabled, indeed it's hanging the qemu process when doing the switch to new disk. 
>>>data copy itself seem to works. 
>>>I think this is a qemu bug, it should work. 

qemu bug report 
https://bugzilla.redhat.com/show_bug.cgi?id=1339498


The fix is in qemu 2.7
"
commit 348295838384941d1e5420d10e57366c4e303d45
Author: Fam Zheng <famz at redhat.com>
Date:   Mon May 23 10:19:37 2016 +0800

    virtio-blk: Remove op blocker for dataplane

"
https://lists.gnu.org/archive/html/qemu-devel/2016-05/msg03713.html




----- Mail original -----
De: "aderumier" <aderumier at odiso.com>
À: "pve-devel" <pve-devel at pve.proxmox.com>
Envoyé: Vendredi 19 Août 2016 05:43:52
Objet: Re: [pve-devel] iothread

>>I have just discovered that when iothread is enabled on a disk this 
>>disk cannot be moved online using move disk. 

just tested from ceph to ceph, with iothread enabled, indeed it's hanging the qemu process when doing the switch to new disk. 
data copy itself seem to works. 
I think this is a qemu bug, it should work. 

>>Also as discovered 
>>previously you cannot make a backup of such disk either. 

native qemu backup support them since 2014, but proxmox backup code don't implemented it. 
"block: let backup blockjob run in BDS AioContext" 
http://git.qemu.org/?p=qemu.git;a=commit;h=761731b1805f6ef64eb615e5b82a0801db3cde78 

(Note that I don't known how much code share proxmox vma backup code with qemu backup) 


>>The iothread 
>>current implementation in Proxmox in my opinion is totally useless! 

Well, this is the 2 only things that didn't work currently. I don't think it's "useless". 
Personnaly, I'm using iothread with big databases on ceph, where I need a lot of iops for database journal disk, database datas disk,.... 

----- Mail original ----- 
De: "datanom.net" <mir at datanom.net> 
À: "pve-devel" <pve-devel at pve.proxmox.com> 
Envoyé: Vendredi 19 Août 2016 00:47:58 
Objet: [pve-devel] iothread 

Hi all, 

I have just discovered that when iothread is enabled on a disk this 
disk cannot be moved online using move disk. Also as discovered 
previously you cannot make a backup of such disk either. The iothread 
current implementation in Proxmox in my opinion is totally useless! 

-- 
Hilsen/Regards 
Michael Rasmussen 

Get my public GnuPG keys: 
michael <at> rasmussen <dot> cc 
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xD3C9A00E 
mir <at> datanom <dot> net 
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE501F51C 
mir <at> miras <dot> org 
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE3E80917 
-------------------------------------------------------------- 
/usr/games/fortune -es says: 
I know you believe you understand what you think this fortune says, but 
I'm not sure you realize that what you are reading is not what it means. 

_______________________________________________ 
pve-devel mailing list 
pve-devel at pve.proxmox.com 
http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel