Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Jens Kristian Søgaard
Hi, As far as I mind - IMHO problem is in acpi code creation (own bytecode language). After integrating this interaction into standard suspend/resume signals - there will only problem of guest suspend support for real hardware. So, nothing special. You're right - it is nothing special... but t

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Dzianis Kahanovich
As far as I mind - IMHO problem is in acpi code creation (own bytecode language). After integrating this interaction into standard suspend/resume signals - there will only problem of guest suspend support for real hardware. So, nothing special. Jens Kristian Søgaard пишет: > Hi, > >> IMHO interac

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Dzianis Kahanovich
Speed is not critical even for usual snapshot. I don't look into qemu code, but x86 arch normal fork process is in splitting virtual address space and copy-on-write both "compacted" copies. So, "snapshot" is momental in time (mean not copy nothing real RAM, just fix descriptors), but forked copy ca

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Jens Kristian Søgaard
Hi, IMHO interaction QEMU & kernel's FREEZER (part of hibernation & cgroups) can solve many of problems. It can be done via QEMU host-2-guest sockets and scripts That would require a cooperating VM. What I was looking at was how to do this for non-cooperating VMs. -- Jens Kristian Søgaard,

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Jens Kristian Søgaard
Hi, I`ve thought of the same mechanism a lot ago. After couple of tests I have concluded that coredump should be done not to Ceph directly, but to the tmpfs catalog to decrease VM` idle timeout(explicitly for QEMU, I see that more like as an implementation detail - i.e. the state is initially

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Andrey Korolyov
If I understood you right, your approach is a suspend VM via ACPI mechanism, then dump core, then restore it - this should be longer than simple coredump due timings for guest OS to sleep/resume, which seems unnecessary. Copy-on-write mechanism should reduce downtime to very acceptable values but u

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Dzianis Kahanovich
Freezer in guest agent? Exists or todo? Dzianis Kahanovich пишет: > IMHO interaction QEMU & kernel's FREEZER (part of hibernation & cgroups) can > solve many of problems. It can be done via QEMU host-2-guest sockets and > scripts > or embedded into virtual hardware (simulate real "suspend" behavi

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Dzianis Kahanovich
IMHO interaction QEMU & kernel's FREEZER (part of hibernation & cgroups) can solve many of problems. It can be done via QEMU host-2-guest sockets and scripts or embedded into virtual hardware (simulate real "suspend" behavior). Andrey Korolyov пишет: > Hello, > > I`ve thought of the same mechanis

Re: [ceph-users] Ceph and Qemu

2013-05-18 Thread Andrey Korolyov
Hello, I`ve thought of the same mechanism a lot ago. After couple of tests I have concluded that coredump should be done not to Ceph directly, but to the tmpfs catalog to decrease VM` idle timeout(explicitly for QEMU, if other hypervisor able to work with Ceph backend and has COW-like memory snaps

[ceph-users] Ceph and Qemu

2013-05-18 Thread Jens Kristian Søgaard
Hi guys, I was wondering if anyone has done some work on saving qemu VM state (RAM, registers, etc.) on Ceph itself? The purpose for me would be to enable easy backups of non-cooperating VMs - i.e. without the need to quiesce file systems, databases, etc. I'm thinking an automated process w