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Content Owner: Roman Macek | ||||
Summary
SPM and support for shared FS; manual SPM role assigment
Details
A host known as the Storage Pool Manager (SPM) manages access between hosts and storage.
The SPM host is the only node that has full access within the storage pool; the SPM can modify the images data, and meta-data and the pools meta-data.
In RHV 3.3 ability was added to manually assigned or re-assigned the Storage Pool Manager role to hosts, using the administration portal or via the REST API.
Additionally RHV has the capability of using any shared file system that the Linux kernel supports (support varies depending on vendor and implementation). For example, IBMs GPFS could be used as a backing store for virtual machines, configured as a POSIX file system for the Storage Domain. Other shared file systems like GFS, future versions of GlusterFS (Red Hat Storage) are considerations, as well. This provides maximum flexibility between traditional NAS (NFS), direct-to-block (standard RHV FC/iSCSI/SAS) and shared file systems (POSIX).
Background: Prior to Red Hat Virtualization 3.1, SPM exclusivity (ensuring the existence of a single arbitrator to avoid data corruption) was maintained and tracked using a feature called safelease. Safe lease only maintained exclusivity of one resource, the SPM role.
Sanlock provides the same functionality, but treats the SPM role as one of the resources that can be locked while allowing additional resources to be locked. Applications that require resource locking can register with Sanlock.
The SPM host is the only node that has full access within the storage pool; the SPM can modify the images data, and meta-data and the pools meta-data.
In RHV 3.3 ability was added to manually assigned or re-assigned the Storage Pool Manager role to hosts, using the administration portal or via the REST API.
Additionally RHV has the capability of using any shared file system that the Linux kernel supports (support varies depending on vendor and implementation). For example, IBMs GPFS could be used as a backing store for virtual machines, configured as a POSIX file system for the Storage Domain. Other shared file systems like GFS, future versions of GlusterFS (Red Hat Storage) are considerations, as well. This provides maximum flexibility between traditional NAS (NFS), direct-to-block (standard RHV FC/iSCSI/SAS) and shared file systems (POSIX).
Background: Prior to Red Hat Virtualization 3.1, SPM exclusivity (ensuring the existence of a single arbitrator to avoid data corruption) was maintained and tracked using a feature called safelease. Safe lease only maintained exclusivity of one resource, the SPM role.
Sanlock provides the same functionality, but treats the SPM role as one of the resources that can be locked while allowing additional resources to be locked. Applications that require resource locking can register with Sanlock.
