Standalone API for VM Quiesce/Unquiesce

[prajasek-netapp]

The required feature described as a wish

Description:
Currently, Apache CloudStack does not provide a dedicated API to quiesce or unquiesce a VM without performing snapshot operations. The only mechanisms available are embedded within the snapshot APIs. For instance:

• When taking a snapshot, the system internally invokes methods to quiesce (freeze the filesystem) and unquiesce (thaw the filesystem) the VM.

Proposal:
I propose that a standalone API for quiescing and unquiescing VMs be implemented in CloudStack. This would help in scenarios such as storage vendor backup procedures that require the VM filesystem to be temporarily frozen without affecting the VM’s overall running state.

Benefits:

• Enhanced backup capabilities without intervening in the VM's operation.
• Better alignment with hypervisor-level features for improved consistency in handling VM states.

[boring-cyborg]

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[DaanHoogland]

@prajasek-netapp , sounds good, will you be implementing such a service/API call?

[prajasek-netapp]

Team, Is it acceptable to implement this API solely for the KVM hypervisor? Considering that CloudStack supports other hypervisors as well, I want to confirm if restricting this API to KVM is a viable approach. Looking forward to your thoughts. Regards, Raj From: dahn ***@***.***> Sent: 12 March 2025 17:53 To: apache/cloudstack ***@***.***> Cc: P, Rajasekar ***@***.***>; Mention ***@***.***> Subject: Re: [apache/cloudstack] Standalone API for VM Quiesce/Unquiesce (Issue #10534) EXTERNAL EMAIL - USE CAUTION when clicking links or attachments @prajasek-netapp<https://urldefense.com/v3/__https:/github.com/prajasek-netapp__;!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF3yW-zogq$> , sounds good, will you be implementing such a service/API call? — Reply to this email directly, view it on GitHub<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/10534*issuecomment-2717706886__;Iw!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF320Krr-D$>, or unsubscribe<https://urldefense.com/v3/__https:/github.com/notifications/unsubscribe-auth/ASEC5OVFEMFI5RTJGUUTMKL2UARJTAVCNFSM6AAAAABYV5F6CKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMJXG4YDMOBYGY__;!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF3_G8CQ0X$>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>> [DaanHoogland]DaanHoogland left a comment (apache/cloudstack#10534)<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/10534*issuecomment-2717706886__;Iw!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF320Krr-D$> @prajasek-netapp<https://urldefense.com/v3/__https:/github.com/prajasek-netapp__;!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF3yW-zogq$> , sounds good, will you be implementing such a service/API call? — Reply to this email directly, view it on GitHub<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/10534*issuecomment-2717706886__;Iw!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF320Krr-D$>, or unsubscribe<https://urldefense.com/v3/__https:/github.com/notifications/unsubscribe-auth/ASEC5OVFEMFI5RTJGUUTMKL2UARJTAVCNFSM6AAAAABYV5F6CKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMJXG4YDMOBYGY__;!!Nhn8V6BzJA!SQdkQdG1QF3sjzlQZP3J8C2hhKLj0EjeGOgbHvLbY1ipMhMIEIkv1ALl9V8DFWoF1ADDv-mgjWNHaphF3_G8CQ0X$>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>>

[DaanHoogland]

Is it acceptable to implement this API solely for the KVM hypervisor? Considering that CloudStack supports other hypervisors as well, I want to confirm if restricting this API to KVM is a viable approach.

It is understandable, some hypervisors support different features than others. It is not desirable. So if it can be avoided that is good. It also needs to be made clear in both the API docs and in error messages returned by the API.

That all said @prajasek-netapp , yes, why not?

[weizhouapache]

@prajasek-netapp
there were some discussion between João and you on the security concerns. will you still want this feature ?

there was a discussion on sending commands to vm via qemu guest agent #9577
I think libvirt also quiesce the vm via qemu GA command (maybe guest-fsfreeze-freeze), right ?

[prajasek-netapp]

Hi, We discussed on API, like libvirt, which allows us to run the arbitrary commands on the VM host. But not on exposing the Quiesce API. Thanks, Raj. From: Wei Zhou ***@***.***> Sent: 13 March 2025 14:43 To: apache/cloudstack ***@***.***> Cc: P, Rajasekar ***@***.***>; Mention ***@***.***> Subject: Re: [apache/cloudstack] Standalone API for VM Quiesce/Unquiesce (Issue #10534) EXTERNAL EMAIL - USE CAUTION when clicking links or attachments @prajasek-netapp<https://urldefense.com/v3/__https:/github.com/prajasek-netapp__;!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCnr0VYbvR$> there were some discussion between João and you on the security concerns. will you still want this feature ? there was a discussion on sending commands to vm via qemu guest agent #9577<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/9577__;!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCno5E5twL$> I think libvirt also quiesce the vm via qemu GA command (maybe guest-fsfreeze-freeze), right ? — Reply to this email directly, view it on GitHub<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/10534*issuecomment-2720521826__;Iw!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCni215M9I$>, or unsubscribe<https://urldefense.com/v3/__https:/github.com/notifications/unsubscribe-auth/ASEC5OQCUBYQRMPGGABKAYD2UFDY7AVCNFSM6AAAAABYV5F6CKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMRQGUZDCOBSGY__;!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCnqE-vPNS$>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>> [weizhouapache]weizhouapache left a comment (apache/cloudstack#10534)<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/10534*issuecomment-2720521826__;Iw!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCni215M9I$> @prajasek-netapp<https://urldefense.com/v3/__https:/github.com/prajasek-netapp__;!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCnr0VYbvR$> there were some discussion between João and you on the security concerns. will you still want this feature ? there was a discussion on sending commands to vm via qemu guest agent #9577<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/9577__;!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCno5E5twL$> I think libvirt also quiesce the vm via qemu GA command (maybe guest-fsfreeze-freeze), right ? — Reply to this email directly, view it on GitHub<https://urldefense.com/v3/__https:/github.com/apache/cloudstack/issues/10534*issuecomment-2720521826__;Iw!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCni215M9I$>, or unsubscribe<https://urldefense.com/v3/__https:/github.com/notifications/unsubscribe-auth/ASEC5OQCUBYQRMPGGABKAYD2UFDY7AVCNFSM6AAAAABYV5F6CKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMRQGUZDCOBSGY__;!!Nhn8V6BzJA!Qu2gfBwZuJ-tU2n23DQD9sRs5-g5pMQNtb4JvZnMbCmL5w5tRyi8bsb6VO97qtv-9H1hLEap_N8zL_VCnqE-vPNS$>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>>