About ----- Ceph Windows support is currently a work in progress. For now, the main focus is the client side, allowing Windows hosts to consume rados, rbd and cephfs resources. .. _building: Building -------- At the moment, mingw gcc >= 8 is the only supported compiler for building ceph components for Windows. Support for msvc and clang will be added soon. `win32_build.sh`_ can be used for cross compiling Ceph and its dependencies. It may be called from a Linux environment, including Windows Subsystem for Linux. MSYS2 and CygWin may also work but those weren't tested. This script currently supports Ubuntu 20.04 and openSUSE Tumbleweed, but it may be easily adapted to run on other Linux distributions, taking into account different package managers, package names or paths (e.g. mingw paths). .. _win32_build.sh: win32_build.sh The script accepts the following flags: ================= =============================== =============================== Flag Description Default value ================= =============================== =============================== OS Host OS distribution, for mingw ubuntu (also valid: suse) and other OS specific settings. CEPH_DIR The Ceph source code directory. The same as the script. BUILD_DIR The directory where the $CEPH_DIR/build generated artifacts will be placed. DEPS_DIR The directory where the Ceph $CEPH_DIR/build.deps dependencies will be built. NUM_WORKERS The number of workers to use The number of vcpus when building Ceph. available CLEAN_BUILD Clean the build directory. SKIP_BUILD Run cmake without actually performing the build. SKIP_TESTS Skip building Ceph tests. SKIP_ZIP If unset, we'll build a zip archive containing the generated binaries. ZIP_DEST Where to put a zip containing $BUILD_DIR/ceph.zip the generated binaries. EMBEDDED_DBG_SYM By default, the generated archive will contain a .debug subfolder, having the debug symbols. If this flag is set, the debug symbols will remain embedded in the executables. ENABLE_SHARED Dynamically link Ceph libs. False ================= =============================== =============================== The following command will build the binaries and add them to a zip archive along with all the required DLLs. By default, the debug symbols are extracted from the binaries and placed in the ".debug" folder of the archive. .. code:: bash SKIP_TESTS=1 ./win32_build.sh In order to disable a flag, such as ``CLEAN_BUILD``, leave it undefined. ``win32_build.sh`` will fetch dependencies using ``win32_deps_build.sh``. If all dependencies are successfully prepared, this potentially time consuming step will be skipped by subsequent builds. Be aware that you may have to do a clean build (using the ``CLEAN_BUILD`` flag) when the dependencies change (e.g. after switching to a more recent Ceph version by doing a ``git pull``). Make sure to explicitly pass the "OS" parameter when directly calling ``win32_deps_build.sh``. Also, be aware of the fact that it will use the distro specific package manager, which will require privileged rights. Current status -------------- Ceph filesystems can be mounted using the ``ceph-dokan`` command, which requires the Dokany package to be installed. Note that dokany is a well maintained fork of the Dokan project, allowing filesystems to be implemented in userspace, pretty much like Fuse. RBD images can be mounted using the ``rbd`` or ``rbd-wnbd`` commands. The ``WNBD`` driver is required for mapping RBD images on Windows. A significant number of tests from the ``tests`` directory have been ported, providing adequate coverage. Supported platforms =================== Windows Server 2019 and Windows Server 2016 are supported. Previous Windows Server versions, including Windows client versions such as Windows 10, might work but haven't been tested. Windows Server 2016 does not provide unix sockets, in which case the Ceph admin socket feature will be unavailable. Compatibility ============= RBD images can be exposed to the OS and host Windows partitions or they can be attached to Hyper-V VMs in the same way as iSCSI disks. At the moment, the Microsoft Failover Cluster can't use WNBD disks as Cluster Shared Volumes (CSVs) underlying storage. The main reason is that ``WNBD`` and ``rbd-wnbd`` don't support the *SCSI Persistent Reservations* feature yet. OpenStack integration has been proposed as well and will most probably be included in the next OpenStack release, allowing RBD images managed by OpenStack Cinder to be attached to Hyper-V VMs managed by OpenStack Nova. .. _installing: Installing ---------- The following project allows building an MSI installer that bundles ``ceph`` and the ``WNBD`` driver: https://github.com/cloudbase/ceph-windows-installer In order to manually install ``ceph``, start by unzipping the binaries that you may have obtained by following the building_ step. You may want to update the environment PATH variable, including the Ceph path. Assuming that you've copied the Ceph binaries to ``C:\Ceph``, you may use the following Powershell command: .. code:: bash [Environment]::SetEnvironmentVariable("Path", "$env:PATH;C:\ceph", "Machine") In order to mount Ceph filesystems, you will have to install Dokany. You may fetch the installer as well as the source code from the Dokany Github repository: https://github.com/dokan-dev/dokany/releases The minimum supported Dokany version is 1.3.1. At the time of the writing, Dokany 2.0 is in Beta stage and is unsupported. In order to map RBD images, the ``WNBD`` driver must be installed. Please check out this page for more details about ``WNBD`` and the install process: https://github.com/cloudbase/wnbd Configuring ----------- ceph.conf ========= The default location for the ``ceph.conf`` file on Windows is ``%ProgramData%\ceph\ceph.conf``, which usually expands to ``C:\ProgramData\ceph\ceph.conf``. Below you may find a sample. Please fill in the monitor addresses accordingly. .. code:: ini [global] log to stderr = true run dir = C:/ProgramData/ceph/out crash dir = C:/ProgramData/ceph/out [client] keyring = C:/ProgramData/ceph/keyring ; log file = C:/ProgramData/ceph/out/$name.$pid.log admin socket = C:/ProgramData/ceph/out/$name.$pid.asok ; client_permissions = true ; client_mount_uid = 1000 ; client_mount_gid = 1000 [global] mon host = Assuming that you're going to use this config sample, don't forget to also copy your keyring file to the specified location and make sure that the configured directories exist (e.g. ``C:\ProgramData\ceph\out``). Please use slashes ``/`` instead of backslashes ``\`` as path separators within ``ceph.conf`` for the time being. .. _windows_service: Windows service =============== On Windows, rbd-wnbd daemons are managed by a centralized service. This allows decoupling the daemons from the Windows session from which they originate. At the same time, the service is responsible of recreating persistent mappings, usually when the host boots. Note that only one such service may run per host. By default, all image mappings are persistent. Non-persistent mappings can be requested using the ``-onon-persistent`` ``rbd`` flag. Persistent mappings are recreated when the service starts, unless explicitly unmapped. The service disconnects the mappings when being stopped. This also allows adjusting the Windows service start order so that rbd images can be mapped before starting services that may depend on it, such as VMMS. In order to be able to reconnect the images, ``rbd-wnbd`` stores mapping information in the Windows registry at the following location: ``SYSTEM\CurrentControlSet\Services\rbd-wnbd``. The following command can be used to configure the service. Please update the ``rbd-wnbd.exe`` path accordingly. .. code:: PowerShell New-Service -Name "ceph-rbd" ` -Description "Ceph RBD Mapping Service" ` -BinaryPathName "c:\ceph\rbd-wnbd.exe service" ` -StartupType Automatic Usage ----- Cephfs ====== Please check the `ceph-dokan documentation`_ for more details. RBD === The ``rbd`` command can be used to create, remove, import, export, map or unmap images exactly like it would on Linux. Mapping images .............. In order to map RBD images, please install ``WNBD``, as mentioned by the installing_ guide. The behavior and CLI is similar to the Linux counterpart, with a few notable differences: * device paths cannot be requested. The disk number and path will be picked by Windows. If a device path is provided by the used when mapping an image, it will be used as an identifier, which can also be used when unmapping the image. * the ``show`` command was added, which describes a specific mapping. This can be used for retrieving the disk path. * the ``service`` command was added, allowing rbd-wnbd to run as a Windows service. All mappings are currently perisistent, being recreated when the service stops, unless explicitly unmapped. The service disconnects the mappings when being stopped. * the ``list`` command also includes a ``status`` column. The purpose of the ``service`` mode is to ensure that mappings survive reboots and that the Windows service start order can be adjusted so that rbd images can be mapped before starting services that may depend on it, such as VMMS. Please follow the windows_service_ guide in order to configure the service. The mapped images can either be consumed by the host directly or exposed to Hyper-V VMs. Hyper-V VM disks ~~~~~~~~~~~~~~~~ The following sample imports an RBD image and boots a Hyper-V VM using it. .. code:: PowerShell # Feel free to use any other image. This one is convenient to use for # testing purposes because it's very small (~15MB) and the login prompt # prints the pre-configured password. wget http://download.cirros-cloud.net/0.5.1/cirros-0.5.1-x86_64-disk.img ` -OutFile cirros-0.5.1-x86_64-disk.img # We'll need to make sure that the imported images are raw (so no qcow2 or vhdx). # You may get qemu-img from https://cloudbase.it/qemu-img-windows/ # You can add the extracted location to $env:Path or update the path accordingly. qemu-img convert -O raw cirros-0.5.1-x86_64-disk.img cirros-0.5.1-x86_64-disk.raw rbd import cirros-0.5.1-x86_64-disk.raw # Let's give it a hefty 100MB size. rbd resize cirros-0.5.1-x86_64-disk.raw --size=100MB rbd device map cirros-0.5.1-x86_64-disk.raw # Let's have a look at the mappings. rbd device list Get-Disk $mappingJson = rbd-wnbd show cirros-0.5.1-x86_64-disk.raw --format=json $mappingJson = $mappingJson | ConvertFrom-Json $diskNumber = $mappingJson.disk_number New-VM -VMName BootFromRBD -MemoryStartupBytes 512MB # The disk must be turned offline before it can be passed to Hyper-V VMs Set-Disk -Number $diskNumber -IsOffline $true Add-VMHardDiskDrive -VMName BootFromRBD -DiskNumber $diskNumber Start-VM -VMName BootFromRBD Windows partitions ~~~~~~~~~~~~~~~~~~ The following sample creates an empty RBD image, attaches it to the host and initializes a partition. .. code:: PowerShell rbd create blank_image --size=1G rbd device map blank_image -onon-persistent $mappingJson = rbd-wnbd show blank_image --format=json $mappingJson = $mappingJson | ConvertFrom-Json $diskNumber = $mappingJson.disk_number # The disk must be online before creating or accessing partitions. Set-Disk -Number $diskNumber -IsOffline $false # Initialize the disk, partition it and create a fileystem. Get-Disk -Number $diskNumber | ` Initialize-Disk -PassThru | ` New-Partition -AssignDriveLetter -UseMaximumSize | ` Format-Volume -Force -Confirm:$false Troubleshooting ............... Wnbd ~~~~ For ``WNBD`` troubleshooting, please check this page: https://github.com/cloudbase/wnbd#troubleshooting Privileges ~~~~~~~~~~ Most ``rbd-wnbd`` and ``rbd device`` commands require privileged rights. Make sure to use an elevated PowerShell or CMD command prompt. Crash dumps ~~~~~~~~~~~ Userspace crash dumps can be placed at a configurable location and enabled for all applications or just predefined ones, as outlined here: https://docs.microsoft.com/en-us/windows/win32/wer/collecting-user-mode-dumps. Whenever a Windows application crashes, an event will be submitted to the ``Application`` Windows Event Log, having Event ID 1000. The entry will also include the process id, the faulting module name and path as well as the exception code. Please note that in order to analyze crash dumps, the debug symbols are required. We're currently buidling Ceph using ``MinGW``, so by default ``DWARF`` symbols will be embedded in the binaries. ``windbg`` does not support such symbols but ``gdb`` can be used. ``gdb`` can debug running Windows processes but it cannot open Windows minidumps. The following ``gdb`` fork may be used until this functionality is merged upstream: https://github.com/ssbssa/gdb/releases. As an alternative, ``DWARF`` symbols can be converted using ``cv2pdb`` but be aware that this tool has limitted C++ support. ceph tool ~~~~~~~~~ The ``ceph`` Python tool can't be used on Windows natively yet. With minor changes it may run, but the main issue is that Python doesn't currently allow using ``AF_UNIX`` on Windows: https://bugs.python.org/issue33408 As an alternative, the ``ceph`` tool can be used through Windows Subsystem for Linux (WSL). For example, running Windows RBD daemons may be contacted by using: .. code:: bash ceph daemon /mnt/c/ProgramData/ceph/out/ceph-client.admin.61436.1209215304.asok help IO counters ~~~~~~~~~~~ Along with the standard RBD perf counters, the ``libwnbd`` IO counters may be retrieved using: .. code:: PowerShell rbd-wnbd stats $imageName At the same time, WNBD driver counters can be fetched using: .. code:: PowerShell wnbd-client stats $mappingId Note that the ``wnbd-client`` mapping identifier will be the full RBD image spec (the ``device`` column of the ``rbd device list`` output). .. _ceph-dokan documentation: https://docs.ceph.com/en/latest/cephfs/ceph-dokan/