[OpenAFS] Re: why afs backup is so poorly supported

Marcus Watts mdw@umich.edu
Tue, 10 Oct 2006 17:57:50 -0400

"chas williams - CONTRACTOR" <chas@cmf.nrl.navy.mil> writes:
> bdb supports records up to 4G in size. so this will limit files unless
> you span them across records.  bdb certainly supports partial access
> to records.  it maintains some idea of page size for i/o operations
> (where you choose page size based on your applications, probably 16k
> for afs given the iovec size at the moment).

A very ancient copy of bdb I worked on once had a default page size
based on the filesystem on which it was created, and very large data
fields were implemented as a pointer to the actual data which was
stored in a series of linked pages.  Hopefully they fixed the latter,
otherwise, seeking to random points in data is going to be expensive.