590fb76238
For '-drive', qemu-server sets special cache options for EFI disk using RBD. In preparation to seamlessly switch to the new '-blockdev' interface, do the same here. Note that the issue from bug #3329, which is solved by these cache options, still affects current versions. With -blockdev, the cache options are split up. While cache.direct and cache.no-flush can be set in the -blockdev options, cache.writeback is a front-end property and was intentionally removed from the -blockdev options by QEMU commit aaa436f998 ("block: Remove cache.writeback from blockdev-add"). It needs to be configured as the 'write-cache' property for the ide-hd/scsi-hd/virtio-blk device. The default is already 'writeback' and no cache mode can be set for an EFI drive configuration in Proxmox VE currently, so there will not be a clash. ┌─────────────┬─────────────────┬──────────────┬────────────────┐ │ │ cache.writeback │ cache.direct │ cache.no-flush │ ├─────────────┼─────────────────┼──────────────┼────────────────┤ │writeback │ on │ off │ off │ ├─────────────┼─────────────────┼──────────────┼────────────────┤ │none │ on │ on │ off │ ├─────────────┼─────────────────┼──────────────┼────────────────┤ │writethrough │ off │ off │ off │ ├─────────────┼─────────────────┼──────────────┼────────────────┤ │directsync │ off │ on │ off │ ├─────────────┼─────────────────┼──────────────┼────────────────┤ │unsafe │ on │ off │ on │ └─────────────┴─────────────────┴──────────────┴────────────────┘ Table from 'man kvm'. Alternatively, the option could only be set once when allocating the RBD volume. However, then we would need to detect all cases were a volume could potentially be used as an EFI disk later. Having a custom disk type would help a lot there. The approach here was chosen as it is catch-all and should not be too costly either. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>