It seems I have erasure pools. https://docs.ceph.com/en/latest/rados/operations/erasure-code/#erasure-coding-with-overwrites On Tue, Jan 26, 2021 at 12:02 PM Cary FitzHugh <cary.fitzhugh@xxxxxxxxx> wrote: > are there any good documents on the implicit requirements for librados > calls? > > I can write a file, if it doesn't exist successfully. > I can write_full a file, and it works (but many of my files will need to > be chunked off disk, not enough RAM) > I can append to a nonexistent file and it works. > > I *cannot* write to a part of an existing file (overwrite a section of it > or write past it's current size) --> Errno 95 > I *cannot* append to an existing file --> Errno 95 > I *cannot* trunc an existing file (nor a non existent file) --> Errno 95 > (what is the point of this then??) > > any ideas / where can one see more detailed semantics of what operations > are allowed and when? > > The librados C API does not really go into any detail about errors and why > things happen as they do. > This behavior seems similar whether I am admin or a separate user. > > Thanks for any pointers. > Cary > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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