[Qemu-devel] 答复： Re: RFC: Make 'info snapshots' show all of snapshots with multiple devices info

[Lin Ma]

>>> Kevin Wolf <address@hidden> 2016/5/23 星期一 下午 5:00 >>>
>Am 22.05.2016 um 11:55 hat Lin Ma geschrieben:
>> Currently, the output of 'info snapshots' show fully available snapshots.
>>  
>> In my opinion there are 2 disadvantages:
>> 1. It's opaque, hides some snapshot information to users. It's not convenient
>> if users want to know more about all of snapshots on every block device via
>> monitor.
>>  
>> 2. It uses snapshot id to determine whether the snapshots are 'fully
>> available'.
>> It causes incorrect output in some scenario.
>>  
>> For instance:
>> (qemu) info block
>> drive_image1 (#block113): /opt/vms/SLES12-SP1-JeOS-x86_64-GM/disk0.qcow2
>> (qcow2)
>>       Cache mode:       writeback
>>  
>> drive_image2 (#block349): /opt/vms/SLES12-SP1-JeOS-x86_64-GM/disk1.qcow2
>> (qcow2)
>>       Cache mode:       writeback
>> (qemu)
>> (qemu) info snapshots
>> There is no snapshot available.
>> (qemu)
>> (qemu) snapshot_blkdev_internal drive_image1 snap1
>> (qemu)
>> (qemu) info snapshots
>> There is no suitable snapshot available
>> (qemu)
>> (qemu) savevm checkpoint-1
>> (qemu)
>> (qemu) info snapshots
>> ID       TAG                             VM SIZE                        DATE 
>>          VM CLOCK
>> 1             snap1                                   0 2016-05-22 16:57:31  
>>  00:01:30.567
>> (qemu)
>> 
>> $ qemu-img snapshot -l disk0.qcow2
>> Snapshot list:
>> ID       TAG                             VM SIZE                        DATE 
>>          VM CLOCK
>> 1             snap1                                   0 2016-05-22 16:57:31  
>>  00:01:30.567
>> 2             checkpoint-1              165M 2016-05-22 16:58:07   
>> 00:02:06.813
>> 
>> $ qemu-img snapshot -l disk1.qcow2
>> Snapshot list:
>> ID       TAG                             VM SIZE                        DATE 
>>          VM CLOCK
>> 1             checkpoint-1                     0 2016-05-22 16:58:07   
>> 00:02:06.813
>>  
>>  
>>  
>> I'd like to patch it to make the output looking like this:
>> (qemu) info snapshots
>>  
>> Snapshot list from drive_image1:
>> ID       TAG                             VM SIZE                        DATE 
>>          VM CLOCK
>> 1             snap1                                   0 2016-05-22 16:57:31  
>>  00:01:30.567
>> 2             checkpoint-1              165M 2016-05-22 16:58:07   
>> 00:02:06.813
>>  
>> 
>> Snapshot list from  drive_image2:
>> ID       TAG                             VM SIZE                        DATE 
>>          VM CLOCK
>> 1             checkpoint-1                     0 2016-05-22 16:58:07   
>> 00:02:06.813
>
>I think that would clutter the output too much in the common case where
>all images have the same snapshots. How about having a list with all
>loadable snapshots first, and then only an additional list for images
>that have snapshots that aren't present on all images?
>
>(qemu) info snapshots
>List of snapshots present on all disks:
>ID         TAG                             VM SIZE                        DATE 
>         VM CLOCK
>--         checkpoint-1                  165M 2016-05-22 16:58:07   
>00:02:06.813
Double short dash, good idea.

>List of partial (non-loadable) snapshots on 'drive_image1':
>ID         TAG                             VM SIZE                        DATE 
>         VM CLOCK
>1               snap1                                   0 2016-05-22 16:57:31  
> 00:01:30.567
These looks more convenient. I'll do it follow this format, Thanks.
 
 
Lin