Accessing from multiple computers sequenctially (NOT simultaneously)?

[bdwa...@gmail.com]

Is it possible to access an s3backer file system from multiple computers sequentially?  I understand that simultaneous mounts are not possible.  I'd like to be able to access the same files from more than one computer, but only from one computer at a time.

A related question: is the 'one big file' that s3backer creates stored locally only, or is it also put into s3?

thanks

[Archie Cobbs]

On Wed, Mar 30, 2016 at 2:26 PM, <bdwa...@gmail.com> wrote:

Is it possible to access an s3backer file system from multiple computers sequentially?  I understand that simultaneous mounts are not possible.  I'd like to be able to access the same files from more than one computer, but only from one computer at a time.

Yes this should work fine. Amazon doesn't know the difference.

HOWEVER, there is a possible issue when you have a local, on-disk block cache configured. If you dismount the filesystems cleanly each time you should be OK, but you must wait for s3backer to exit completely .. see this item from the man page:

BUGS
     Due to a design flaw in FUSE, an unmount of the s3backer filesystem will com-
     plete successfully before s3backer has finished writing back all dirty blocks.
     Therefore, when using the block cache, attempts to remount the same bucket and
     prefix may fail with an 'already mounted' error while the former s3backer
     process finishes flusing its cache.  Before assuming a false positive and
     using --reset-mounted-flag, ensure that any previous s3backer process attached
     to the same bucket and prefix has exited.  See issue #40 for details.
 

A related question: is the 'one big file' that s3backer creates stored locally only, or is it also put into s3?

The "one big file" appears as a local file, but only when s3backer is running and mounted. The data in the file is stored in an S3 bucket, partitioned into blocks. Each block is a separate S3 object. Blocks may also be cached locally to improve performance.

-Archie

--

Archie L. Cobbs