DFS without replication

[Dave]

I would like to use DFS to consolodate the storage space on three file
servers which house home directories.

I have:

\\SERVER1\USERS
\\SERVER2\USERS
\\SERVER3\USERS

each containing a couple hundred home directories. I'd like to create
a global link under DFS called "Users" such that all home directories
can be accessed with one DFS name like:

\\MYDOMAIN\DFS\USERS

However, what I DON'T want is for the information on each indivudual
"USERS" share to replicate to all targets. So basically I am not
doing this for fault-tolerance....I am doing it merely to consoldate.

How can this or CAN this be done with Windows 2003 Server and DFS?

 

[Chriss3 [MVP]]

No, it can't,
All can be accessed by \\SERVER\DFS\Users
But only one server at once can be active, so you can't consolidate content
without replication.

--
Regards
Christoffer Andersson
Microsoft MVP - Directory Services

No email replies please - reply in the newsgroup

 

[SixDoubleO]

Correct me if I'm wrong, but shouldnt this functionality exist? Am I
the only one who sees this as a no-brainer? I mean consider this...

I need 600GB for my user home directories.

Server1 has 100GB
Server2 has 200GB
Server3 has 300GB

Shouldn't I be able to consolodate these three resources into one
logical resource, thus making better use of the space?

Further, when I need to add to the "User" share, I should be able to add
to this with a "Server4".

There should be a way to add storage to DFS the same way you can add
storage to a volume.

Is there some other way to do what I'm asking?

Thanks for the help.

Dave

 

[Paul Nelson]

OK - If you could do this, where would the storage for user "johndoe" be
located? It would have to be on only one of the servers right?

How would you as the administrator specify which server johndoe's home
folder is on?

You could use DFS with only a single server in a link. This would allow you
to specify where a user's home folder is, and then not have to change it if
you later move it to a different server. Is this what you mean?

For example, the user's home folder could be specified as:
\\domain.xxx\dfsroot\homes\j\johndoe

You could make \\domain.xxx\dfsroot\homes\j point to a share on server2, and
later move that to a different volume on server2 or to a different server
using DFS.

 

[SixDoubleO]

Well, I would assume that the DFS service would decide which server to
stick johndoe's folder on. The same way NTFS decides which partition in
a multi-partition volume set on.

Anyway, just a wish of mine I suppose.

I see where you're going with your example, which does address the issue
of not having to change server names in the event of a server change,
but I was looking at from the standpoint of being able to easily add,
say 200GB, to my user home directory storage pretty easily. Oh well.

 

[Shana]

Dave:

You can definitely use DFS to consolidate the namespace, and make
future moves more transparent to users. This is one of the things DFS
is designed to do. (Disclaimer : I have only done this on Win2k3)

Dont worry about replication. Replication is not on by default until
you configure a place to replicate to, so you do not have to do
anything to avoid replication.

You simply make a DFS root such as \\domain.com\home.
To that root you then link each individual home directory.

ie
add a link called adam to \\domain.com\home\ pointing to
\\SERVER1\USERS\adam
dfscmd /map \\domain.com\home\zack \\SERVER1\USERS\zack

add a link called zack to \\domain.com\home\ pointng to
\\SERVER1\USERS\zack
dfscmd /map \\domain.com\home\zack \\SERVER1\USERS\zack

This way, irrespective of which server physically holds the directory,
their home directory will always be \\domain.com\home\username.

Doing this manually for a small number of users would be trivial, but
scaling up to hundreds of usernames is not much fun. The obstacle to
automating it is you, as an administrator, knowing which server the
home directory is (or should be) on.

One solution would be to organize the home directories by first letter
on the servername.

i.e.
A-H on \\SERVER1\USER\username
I-P on \\SERVER2\USER\username
Q-Z on \\SERVER3\USER\username

A quick analysis of your usernames and disk usage will show you where
you need to make the breaks to distribute data evenly between the
three servers (names beginning with J are much more common than names
beginning with X). You can allow the scheme to get pretty complicated,
because users are not required to understand it. It can be easily
taken care of in a script.

Those in the thread who said it can not be done were probably thinking
that you wanted to put a single dfs link on the users directory, and
have it point to the three different places as opposed to one link for
each home directory.
i.e. Add a link or root called users with three different targets.
dfscmd /map \\domain.com\dfs\users \\SERVER1\USERS\
dfscmd /add \\domain.com\dfs\users \\SERVER2\USERS\
dfscmd /add \\domain.com\dfs\users \\SERVER3\USERS\
Without replication.
I agree that it would not be a good approach to your problem.


<--10 second soap box -->
Please consider automating stuff like this so that you are spending
your time on more challenging problems, and so that policies and
decisions are consistently applied.
<--end soapbox, sorry -->

<--scalability disclaimer -->
I have read that Microsoft claims that a domain based DFS root can
have upto 5000 links. A standalone DFS server can have upto 50,000
links.
<--end scalability disclaimer -->

Shana
Not an MVP
Linux, Solaris, NT, Win2k, Win2k3 administrator, among other things.
http://www.technologysimplifiedllc.com
(Brand new and under heavy construction. Be nice.)

 

[Shana]

Dave:

You can definitely use DFS to consolidate the namespace, and make
future moves more transparent to users. This is one of the things DFS
is designed to do. (Disclaimer : I have only done this on Win2k3)

Dont worry about replication. Replication is not on by default until
you configure a place to replicate to, so you do not have to do
anything to avoid replication.

You simply make a DFS root such as \\domain.com\home.
To that root you then link each individual home directory.

ie
add a link called adam to \\domain.com\home\ pointing to
\\SERVER1\USERS\adam
dfscmd /map \\domain.com\home\adam \\SERVER1\USERS\adam

add a link called zack to \\domain.com\home\ pointng to
\\SERVER1\USERS\zack
dfscmd /map \\domain.com\home\zack \\SERVER1\USERS\zack

This way, irrespective of which server physically holds the directory,
their home directory will always be \\domain.com\home\username.

Doing this manually for a small number of users would be trivial, but
scaling up to hundreds of usernames is not much fun. The obstacle to
automating it is you, as an administrator, knowing which server the
home directory is (or should be) on.

One solution would be to organize the home directories by first letter
on the servername.

i.e.
A-H on \\SERVER1\USER\username
I-P on \\SERVER2\USER\username
Q-Z on \\SERVER3\USER\username

A quick analysis of your usernames and disk usage will show you where
you need to make the breaks to distribute data evenly between the
three servers (names beginning with J are much more common than names
beginning with X). You can allow the scheme to get pretty complicated,
because users are not required to understand it. It can be easily
taken care of in a script.

Those in the thread who said it can not be done were probably thinking
that you wanted to put a single dfs link on the users directory, and
have it point to the three different places as opposed to one link for
each home directory.
i.e. Add a link or root called users with three different targets.
dfscmd /map \\domain.com\dfs\users \\SERVER1\USERS\
dfscmd /add \\domain.com\dfs\users \\SERVER2\USERS\
dfscmd /add \\domain.com\dfs\users \\SERVER3\USERS\
Without replication.
I agree that it would not be a good approach to your problem.


<--10 second soap box -->
Please consider automating stuff like this so that you are spending
your time on more challenging problems, and so that policies and
decisions are consistently applied.
<--end soapbox, sorry -->

<--scalability disclaimer -->
I have read that Microsoft claims that a domain based DFS root can
have upto 5000 links. A standalone DFS server can have upto 50,000
links.
<--end scalability disclaimer -->

Shana
Not an MVP
Linux, Solaris, NT, Win2k, Win2k3 administrator, among other things.
http://www.technologysimplifiedllc.com
(Brand new and under heavy construction. Be nice.)