> -----Original Message----- > From: Chiradeep Vittal [mailto:chiradeep.vit...@citrix.com] > Sent: Thursday, July 05, 2012 3:54 PM > To: CloudStack DeveloperList > Subject: Re: First review of RBD support for primary storage > > I took a first glance at this. Really pleased about this feature. EBS- > like > scalable primary storage is within reach! > > A few comments: > 1. I see quite a few blocks of code ( > 20 times?) that are like > if (pool.getType() == StoragePoolType.RBD) > I realize that there is existing code that does these kinds of > checks > as well. To me this can be solved simply by the "chain of > responsibility" > pattern: you hand over the operation to a configured chain of handlers. > The first handler (usually) that says it can handle it, terminates the > chain.
It's in my to-do-list, refactor storage part code, to make adding a new storage type into cloudstack much easier. > 2. 'user_info' can actually be pushed into the 'storage_pool_details' > table. Generally we avoid modifying existing tables if we can. > 3. Copying a snapshot to secondary storage is desirable: to be > consistent > with other storage types, to be able to instantiate new volumes in > other > zones (when S3 support is available across the region). I'd like to > understand the blockers here. > > > On 7/2/12 5:59 AM, "Wido den Hollander" <w...@widodh.nl> wrote: > > >Hi, > > > >On 29-06-12 17:59, Wido den Hollander wrote: > >> Now, the RBD support for primary storage knows limitations: > >> > >> - It only works with KVM > >> > >> - You are NOT able to snapshot RBD volumes. This is due to > CloudStack > >> wanting to backup snapshots to the secondary storage and uses 'qemu- > img > >> convert' for this. That doesn't work with RBD, but it's also very > >> inefficient. > >> > >> RBD supports native snapshots inside the Ceph cluster. RBD disks > also > >> have the potential to reach very large sizes. Disks of 1TB won't be > the > >> exception. It would stress your network heavily. I'm thinking about > >> implementing "internal snapshots", but that is step #2. For now no > >> snapshots. > >> > >> - You are able create a template from a RBD volume, but creating a > new > >> instance with RBD storage from a template is still a hit-and-miss. > >> Working on that one. > >> > > > >I just pushed a fix for creating instances from a template. That > should > >work now! > > > >Wido
