[OpenAFS] Re: Change in volume status during vos dump in OpenAFS 1.6.x

[Andy Malato]

! Date: Wed, 13 Mar 2013 22:57:02 -0400
! From: Jeffrey Altman <jaltman@your-file-system.com>
! To: matthew.hoskins@njit.edu
! Cc: openafs-info@openafs.org
! Subject: Re: [OpenAFS] Re: Change in volume status during vos dump in OpenAFS
!     1.6.x
!
! Matt:
!
! Have you looked at the man pages?
!
!   http://docs.openafs.org/Reference/index
!
! The pages for "fs listquota", "fs quota", "fs setquota", "fs setvol",
! "vos clone", "vos copy", "vos create", "vos examine", "vos move", "vos
! partinfo", and "vos shadow" include the following text:
!
! "Currently, the maximum quota for a volume is 2 terabytes (2^41 bytes).
! Note that this only affects the volume's quota; a volume may grow much
! larger if the volume quota is disabled. However, volumes over 2
! terabytes in size may be impractical to move, and may have their size
! incorrectly reported by some tools, such as L<fs_listquota(1)>."

So while a volume can grow to more than 2 terabytes in size, the various
tools may not work correctly with volumes this large ?  Are there any
plans to address these issues and to allow quotas larger than than 2tb ?

As more and more researchers continue to work with big data, the request
for multi terabyte volumes is becoming more frequent.  We are starting
to get requests from researchers for volumes in the range of 5 to 7TB
and we expect that future requests will probably be even larger.

>From what I read here it appears that AFS may be "impractical" to
support large datasets of this size?  Can you (or anyone else) confirm
other sites that are using AFS to support the use of big data ?

! If you look at the 'fileserver' or 'dafileserver' man pages you will find:
!
! "Currently, the maximum size of a volume quota is 2 terabytes (2^41
! bytes) and the maximum size of a /vicepX partition on a fileserver is
! 2^64 kilobytes. The maximum partition size in releases 1.4.7 and earlier
! is 2 terabytes (2^31 bytes). The maximum partition size for 1.5.x
! releases 1.5.34 and earlier is 2 terabytes as well."
!
! All clients that include "large file" or 64-bit file length support can
! create files larger than 2 terabytes.  File sizes unlike volume quotas
! are represented by signed 64-bit fields instead of a signed 32-bit
! field.  The client versions that support 64-bit files varied by
! operating system and the release builder for a given platform.  If you
! stick with post 1.4.8 clients or any 1.6 client (in the case of
! UNIX/Linux); on Windows, 64-bit file support was added in 1.5.3 (July 2006).
!
! In other words, if you stick to file servers that are 1.4.8 or later you
! have support for partitions and volumes larger than 2TBs.  I hope you
! are because of the security vulnerability, OPENAFS-SA-2009-001,
! http://www.openafs.org/security.  On the client side, if you stick to
! the most recent clients on all platforms you are good to go.

All of our fileservers that are still running 1.4 are now running 1.4.14 with 
the
latest security patches applied to address OPENAFS-SA-2013-001 and 
OPENAFS-SA-2013-002.


!
! Jeffrey Altman
!
!
! On 3/13/2013 9:34 PM, Hoskins, Matthew E. wrote:
! >
! >
! >     Do you have any suggestions on where we could display this information?
! >     You're not the first person to ask this.
! >
! >
! > A table somewhere under wiki.openafs.org <http://wiki.openafs.org> would
! > work...
! > A matrix of Volume and File limits across client and server versions.
! >  But really this matrix and changes to it should be in every release
! > notes of every release.   (or a pointer to where it lives)
! >
! > If the only place this information is "archived" is in the mailing list
! > and buried in commit comments, the bar is WAY too high for new users.
! > (or us old users!)
! >
! >
! >
! >     The Windows client thing is a bug that has several requirements that
! >     must be met in order to trigger it. One of those requirements just
! >     happens to be that you are using a partition over 2TB.
! >
! >
! > For our latest problem, I just need to confirm explicitly.  If we have
! > researchers that need to read/write to:
! >
! >   * Volumes larger than 2TB
! >   * FILES larger than 2TB
! >
! > Is there any combination of client/server versions that are safe for the
! > data.  (Both windows and nix clients)
! >
! > Can we apply quotas on those volumes under any client versions?
! >
! >
! >  Thanks All
! > -Matt
! >
! >
! >
! >     --
! >     Andrew Deason
! >     adeason@sinenomine.net <mailto:adeason@sinenomine.net>
! >
! >     _______________________________________________
! >     OpenAFS-info mailing list
! >     OpenAFS-info@openafs.org <mailto:OpenAFS-info@openafs.org>
! >     https://lists.openafs.org/mailman/listinfo/openafs-info
! >
! >
!
!