[74] in Open-Software-Foundation-News
Soliciting feedback on DFS items in DCE 1.2
daemon@ATHENA.MIT.EDU (Mark_Sherman@transarc.com)
Mon Nov 7 14:10:45 1994
Resent-From: Bill Cattey <wdc@MIT.EDU>
Resent-To: osf-news-mtg@menelaus.LOCAL
Date: Sun, 6 Nov 1994 10:52:01 -0500 (EST)
From: Mark_Sherman@transarc.com
To: sig-dce@osf.org, sig-dce-fs@osf.org, dce-1.2-comments@osf.org
One of the outcomes of last week's DFS subgroup meeting was that some of
the DFS content in DCE 1.2 may be revisited. In particular, the
opportunities are among several not-yet-completed work items that will
be specified, developed and delivered within DCE 1.2 project. (Most of
the other work items already exist in vendors' products, and the DCE 1.2
effort is focused on integrating these items into the mainstream DFS
code base.)
It was suggested at the subgroup meeting to ask for the DFS community's
comments and suggestions on the potential alternatives. This message
contains the list of eight items that were discussed at the meeting.
The *'d items (1-3) are those currently being planned for inclusion in
DCE 1.2, the one without *'s (4-8) are alternatives that currently are
not planned to be in DCE 1.2. To make the feedback quantitative, I'd
like each respondent to "spend" 10 dollars among the proposed
alternatives.
Please send your votes/comments to me, Mark.Sherman@transarc.com. I will
tabulate the results and make them available back to the DFS mailing
list and to the DCE 1.2 committees. Given the various interlocking
development schedules and available resources at the DCE 1.2 sponsor
locations, I cannot guarantee that we can get everything that we want.
However, I am sure that the feedback will be taken very seriously. But,
speed is important. Many details of the DCE 1.2 plans are trying to be
finished so that work can begin in earnest. Therefore, I strongly urge
your feedback *within a week*.
You should feel free to cc interested parties directly. The mailing list
for comments on RFC 63 (the working specification of the DCE 1.2
contents) is dce-1.2-comments@osf.org. The mailing list for the DFS
subgroup is sig-dce-fs@osf.org. The main mailing list for the DCE sig is
sig-dce@osf.org.
-Mark Sherman (DFS subgroup chair)
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Alternative items currently proposed for DCE 1.2:
1. *DFS Administration Lists as ACLs
Provide ACLs to manage DFS administration by placing ACLs someplace
appropriate in the name space rather than using administration lists to
determine authority for managing DFS. This allows one to use security
programs, e.g., acl_edit, to manipulate administrative authority in
addition to DFS commands, e.g., fts.
2. *POSIX.8 Support
The "pathconf" and "getlock" are the specific functions that will be
added to the DFS protocol suite. These are a portion of POSIX.8.
"pathconf" allows an application to obtain parameters about the file
system (e.g. max file name length) which is very useful in a
distributed environment where one may be accessing remote files with
different parameters. "getlock" is used for lock control and has some
unusual implications in a distributed environment like DFS.
3. *VFS+ Submission to X/Open
All of the DCE specifications are to be submitted to X/Open. A draft of
the DFS specification, a.k.a., VFS+ interface, is mostly written but has
not yet been reviewed or submitted. The documentation needs to be
updated, reviewed for accuracy and put into an X/Open format for
submission.
4. 64 bit file system support
DFS currently supports only 32 bit file systems (even on 64 bit
machines). Some additional protocol and interfaces are needed to support
larger than 32 bit file systems in DFS and to allow heterogeneous-sized
(e.g., 32 bit and 64 bit) file systems to interoperate within DFS.
5. Fair Share Cache Policy/Large File Support
Some empirical evidence suggests that one can detect when large files
are being read serially and not cache them. Such files are typically
read once and never reread. With existing algorithms, this kind of
large-file read will effectively flush the entire cache (since the file
is so large), but gain none of the benefits of caching (since the file
is not reread). Hence, one could improve performance by detecting this
situation and not caching the large file.
6. Vendor Specific Protocol Extensions
A general mechanism was proposed to extend the DFS protocol to allow
vendors to add vendor-specific information about their file systems over
the wire, e.g., whether files on the server are migrated. When clients
and servers can interpret this additional information, more
functionality can be provided to the user. Because the protocol is
compatible with existing protocol formats, clients and servers that do
not recognize the protocol extensions can safely ignore them.
7. Extended File Attributes
This item proposes that support be added to permit DFS clients from a
variety of operating system environments to store arbitrary amounts of
additional attribute information for files and directories. This
implementation should be sufficient to support OS/2, Mac System 7,
Windows NT, NetWare and Taligent. Since none of these clients agree on
a common extended attribute implementation, DFS should allow a separate
and distinct attribute stream for each client type.
8. Multihome Support
Today, DCE and DFS require that all clients and servers have
connectivity to each other over all defined network interfaces. Some
users have asked for the ability to use a particular interface for their
DFS data traffic, e.g., FDDI, or export data from a fileserver over
several ip addresses (adaptors). This item would allow a DFS server to
"sit in the middle" of multiple (and otherwise disconnected) networks
and to respond to clients on the same network that the request came from
rather trying an arbitrary network.
----------------------------------------------------------------------
Please email back to Mark.Sherman@transarc.com
Email Ballot (fill in votes in blanks before item, total is "10 dollars")
DFS Administration Lists as ACLs
POSIX.8 Support
VFS+ Submission to X/Open
64 bit file system support
Fair Share Cache Policy/Large File Support
Vendor Specific Protocol Extensions
Extended File Attributes
Multihome Support
Other comments:
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