Open Stack

Excerpts from Samuel Merritt's message of 2014-11-14 10:06:53 -0800:
> On 11/13/14, 10:19 PM, Sachin Goswami wrote:
> > In OpenStack Swift - xfs file system is integrated which provides a
> > maximum file system size of 8 exbibytes minus one byte (263-1 bytes).
> 
> Not exactly. The Swift storage nodes keep their data on POSIX 
> filesystems with support for extended attributes. While XFS filesystems 
> are typically used, XFS is not required.
> 
> > We are studying use of LTFS integration with OpenStack Swift for
> > scenario like - *Data Archival as a Service* .
> >
> > Was integration of LTFS with Swift considered before? If so, can you
> >  please share your study output? Will integration of LTFS with Swift
> > fit into existing Swift architecture ?
> 
> Assuming it's POSIX enough and supports extended attributes, a tape 
> filesystem on a spinning disk might technically work, but I don't see it 
> performing well at all.
> 
> If you're talking about using actual tapes for data storage, I can't 
> imagine that working out for you. Most clients aren't prepared to wait 
> multiple minutes for HTTP responses while a tape laboriously spins back 
> and forth, so they'll just time out.
> 

Agreed. You'd need to have a separate API for freezing and thawing data
I think, similar to the way glacier works. However, my understanding of
glacier is that it is simply a massive bank of cheap disks which are
largely kept powered off until either a ton of requests for data on a
single disk arrive, or a certain amount of time has passed. The benefit
of this is that there is no intermediary storage required. The disks
are either online, and you can read your data, or offline, and you have
to wait.