[libvirt] 答复: Help：Can libvirt restore several xen snapshots more faster at same time?

[Chenjia (C)]

Dear libvirt expert:
	Thanks for your reply.
	May be our description is not suitable, in last message,'snapshot' means the domain state file which 'virsh save ' generate.

	Our project detailed steps are as follows:
	1) create 40 xen guestOS by 'vrish create xen*.xml' 
	2) save 40 guest OS to domain state file by 'virsh save' cmd
	3) Start multiple processes, each process cycle to do the following job:
		a)virsh restore the domain state file
		b)do same job in guest OS in 20 seconds
		c)virsh destroy the guest OS

	We need higher performance on the project , so our question is these as last message:
	1)	each our xen state file is almost same except IP address(Win7 OS with 1G memory), does there have some way to reduce the 40 state file space? 
	2)	Do you have some suggestion to improve the performance of restore as much as  xen state file at same time?

Best regards, wish for your reply.
 
-----邮件原件-----
发件人: Jim Fehlig [mailto:jfehlig at suse.com] 
发送时间: 2017年11月14日 10:01
收件人: Chenjia (C) <chenjia09 at huawei.com>; libvir-list at redhat.com
抄送: HUANG SHENGQIANG <huang.shengqiang at huawei.com>; Yaoshaomin <yaoshaomin at huawei.com>
主题: Re: [libvirt] Help：Can libvirt restore several xen snapshots more faster at same time?

On 11/13/2017 03:31 AM, Chenjia (C) wrote:
> Dear libvirt expert,
> 
> we find a blocker issue in our project. Would you please offer us some feedback?
> 
> Our project have a requirement: restore as much as xen snapshot at same time.  
>   we have done the following test(our environment is cpu E52620,  256G 
> memory, SSD hard disk. The xen snapshot is Win7 OS with 1G memory):
> 
> 1)Save 40 xen snapshots to disk, then restore these snapshot at 
> sametime, we found the restore speed is too slow, and the bottleneck is the IO speed.

You'll have to define "snapshots", since the libvirt Xen drivers do not support any of the virDomainSnapshot* APIs. By snapshot do you mean saving domain state to a file with e.g. 'virsh save ...'?

> 
> 2)we save all the 40 xen snapshot to ramdisk,  then we got a good 
> performance, but the space is too big, about 40G, it is too expensive .
> 
> Our question is :
> 
> 1)each our xen snapshot is almost same except IP address(Win7 OS with 
> 1G memory), does there have some way to reduce the 40 snapshots space?

Maybe I'm being dense, but it is still not clear to me what you mean by "snapshot", or how your snapshots are created and restored.

Regards,
Jim