From: Marcus Sorensen [mailto:shadow...@gmail.com] Sent: Monday, December 10, 2012 3:37 PM To: Edison Su Cc: cloudstack-dev@incubator.apache.org Subject: Re: pluggable storage implementation
Ok, that makes sense. So this will be a part of the storage refactor? If you're not already working on it I'll play with it and see if I can create a working implementation. No plan yet, so many stuff on the management server side to refactor. If you will work on it, that'll be great! I'm assuming we'd have in your example both a getStoragePool(String uuid) that selects the old/default LibvirtStorageAdaptor and a getStoragePool(String storagePoolType, String uuid), so as not to have to redo any existing code? If you are just implementing a new storage for primary storage, then add a new api called getprimarystorage(string pooltype, string uuid). On Mon, Dec 10, 2012 at 1:31 PM, Edison Su <edison...@citrix.com<mailto:edison...@citrix.com>> wrote: KVMStoragePoolManager should manage the mapping between storage pool type and storageadaptor. 1. In KVMStoragePoolManager's constructor, create a map between storage pool type and storageadaptor: sample code: map<String, storageadaptor> storageMapper = new HashMap<String, storageadaptor>(); storageMapper.add("your-storage-type", new your-storage-adaptor); storageMapper.add("libvirt-managed-storage", new LibvirtStorageAdaptor); 2. For each api of KVMStoragePoolManager, should pass down a storage pool type, e.g: public KVMStoragePool getStoragePool(String storagePoolType, String uuid) { storageadaptor adaptor = storageMapper.get(storagepoolType); if (adaptor == null) { adaptor = storageMapper.get("libvirt-managed-storage"); } return adaptor.getStoragePool(uuid); } From: Marcus Sorensen [mailto:shadow...@gmail.com<mailto:shadow...@gmail.com>] Sent: Monday, December 10, 2012 3:06 PM To: Edison Su Cc: cloudstack-dev@incubator.apache.org<mailto:cloudstack-dev@incubator.apache.org> Subject: Re: pluggable storage implementation Yeah, but I'm not seeing an easy/pluggable way to implement a storage adaptor, where LibvirtComputingResource relies exclusively on KVMStoragePoolManager, which is implementing LibvirtStorageAdaptor. I don't see how to switch between storage adaptors in KVMStoragePoolManager.java based on what primary storage type I happen to be acting upon. On Mon, Dec 10, 2012 at 12:51 PM, Edison Su <edison...@citrix.com<mailto:edison...@citrix.com>> wrote: From: Marcus Sorensen [mailto:shadow...@gmail.com<mailto:shadow...@gmail.com>] Sent: Monday, December 10, 2012 2:06 PM To: Edison Su Cc: cloudstack-dev@incubator.apache.org<mailto:cloudstack-dev@incubator.apache.org> Subject: pluggable storage implementation Just curious, hadn't thought about this before but it seems that at least on KVM (probably similar in Xen and VMware too?), there are two separate issues with storage in the existing code. First, adding a new storage type is a matter of adding in a new 'else if' or something in a bunch of different places, as well as tweaking behavior to match the storage type. Second, everything about the storage is tightly integrated with Libvirt, meaning that if your storage type is not supported by Libvirt it's much, much more difficult to implement. Are these both being addressed by the storage changes, for example can we write a storage plugin that creates pools/volumes that libvirt doesn't know about and still attach those to instances? Or would we need to patch libvirt to utilize our storage first? [Edison] That's the storageadaptor used for: https://git-wip-us.apache.org/repos/asf?p=incubator-cloudstack.git;a=blob;f=plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/storage/StorageAdaptor.java;h=ef1e7c9302ab6ac8f197cf75bbf7235bba0235cf;hb=HEAD The LibvirtStorageAdaptor is one of implementation of storageadaptor, which is totally based on libvirt, If you have a new storage, not supported by libvirt, then you can add a new implementation of storageadaptor.
