Nikolay Shirokovskiy 318d807a0b qemu: don't log error for missing optional storage sources on stats
Every time we call all domain stats for inactive domain with
unavailable storage source we get error message in logs [1]. It's a bit noisy.
While it's arguable whether we need such message or not for mandatory
disks we would like not to see messages for optional disks. Let's
filter at least for cases of local files. Fixing other cases would
require passing flag down the stack to .backendInit of storage
which is ugly.

Stats for active domain are fine because we either drop disks
with unavailable sources or clean source which is handled
by virStorageSourceIsEmpty in qemuDomainGetStatsOneBlockFallback.

We have these logs for successful stats since 25aa7035d (version 1.2.15)
which in turn fixes 596a13713 (version 1.2.12 )which added substantial
stats for offline disks.

[1] error message example:
qemuOpenFileAs:3324 : Failed to open file '/path/to/optional/disk': No such file or directory

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
2018-12-21 12:13:31 +03:00
..
2018-12-17 17:52:46 +01:00
2018-12-19 15:32:43 +01:00
2018-12-17 17:52:46 +01:00
2018-12-17 17:52:46 +01:00

       libvirt library code README
       ===========================

The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.

The files directly in this directory are supporting the public API
entry points & data structures.

There are two core shared modules to be aware of:

 * util/  - a collection of shared APIs that can be used by any
            code. This directory is always in the include path
            for all things built

 * conf/  - APIs for parsing / manipulating all the official XML
            files used by the public API. This directory is only
            in the include path for driver implementation modules

 * vmx/   - VMware VMX config handling (used by esx/ and vmware/)


Then there are the hypervisor implementations:

 * bhyve         - bhyve - The BSD Hypervisor
 * esx/          - VMware ESX and GSX support using vSphere API over SOAP
 * hyperv/       - Microsoft Hyper-V support using WinRM
 * lxc/          - Linux Native Containers
 * openvz/       - OpenVZ containers using cli tools
 * phyp/         - IBM Power Hypervisor using CLI tools over SSH
 * qemu/         - QEMU / KVM using qemu CLI/monitor
 * remote/       - Generic libvirt native RPC client
 * test/         - A "mock" driver for testing
 * vbox/         - Virtual Box using native API
 * vmware/       - VMware Workstation and Player using the vmrun tool
 * xen/          - Xen using hypercalls, XenD SEXPR & XenStore
 * xenapi/       - Xen using libxenserver


Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU and Xen drivers.
The ESX, Hyper-V, Power Hypervisor, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly

 * cpu/          - CPU feature management
 * interface/    - Host network interface management
 * network/      - Virtual NAT networking
 * nwfilter/     - Network traffic filtering rules
 * node_device/  - Host device enumeration
 * secret/       - Secret management
 * security/     - Mandatory access control drivers
 * storage/      - Storage management drivers


Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories