Connecting two macs to run programs

Question

Hello,
I've posted elsewhere but was redirected here.
This is a very open ended question about connecting my Mac (Main) to another one (White).
I use open source software such as R, currently on my Macbook. However, my programs are time consuming, so I outsource some of the work to another Macbook that someone lends me, as follows: R is installed on both machines, and I transfer the source files from Main to White using the shared folder.
Is there a better to do this? Ideally I'd like to be able to send instruction from Main to White, and have display of White within Main. Is it asking for too much?
I also have an older Linux machine I'd like to put to use. Here I don't have a shared folder, so I use a flash disk... Any better idea?

Answer 1

I also have an older Linux machine I'd like to put to use. Here I don't have a shared folder, so I use a flash disk... Any better idea?
Mac OS includes support for NFS, the native Unix network file sharing system. You may share files between Mac OS X systems with NFS as well as other Unix Systems. However, the documentation on how you make the shares is rather limited. Once you learn how to configure the net info database with the netinfo command, the shares are not too hard to make.
While it is not require,NFS encourages you to have common UIDs and GIDs.
"NFS Manager is a graphical user interface to control all built-in NFS features of Mac OS X. "
http://www.bresink.de/osx/NFSManager.html
[QUOTE=bogoliubov;2472988]Ok, so how can I check my UID? I've heard that it's dangerous to change the UID, so how should I do if I want the permissions to work in both OSes?[/QUOTE]
You can change the permissions of files and directories in either OS.
I suggest that you make a complete backup of your system. You should create a second administrator account from which you use to change your original account. You should log out your original account before proceeding.
Mac OS X ... harddrive -> Applications -> Utilities -> terminal
Ubuntu ... Applications > Accessories > Terminal
Your current user is:
echo $USER
Let's assume myuser
To find out your UID and GID do:
ls -ln
ls -l
Or, you can use the id command.
id
compare the output and write down what you find.
You best use the numeric value for your userid. In this case it is 500. To list all the files owned by a userid do:
sudo find / -user 500 -exec ls {} \;
# adding a -x before the / limits the search to the current file system.
Mac OS X ... harddrive -> Applications -> Utilities -> NetInfo Manager
In the middle column is the function. Pick users then select your user. Click on the lock at the bottom of the panel. Go into the property list and change UID and GID.
In the Ubuntu terminal,
man 5 passwd
... will give you the format of the passwd file.
sudo nano /etc/passwd
... the format is user-name, password, uid, gid, ...
control-o
... to save
control-x
... to quit
The groups are defined in /etc/group
cat /etc/group
Now change the UID and GID of all files:
You best use the numeric value for your userid. In this case it is 500.
sudo find / -user 500 -exec chown 1100:211 {} \;
/* Where chown has the format of chown uid:gid file-name */
/* adding -print before -exec lists the files that will be changed. */
/* You may want to leave off :211 if your uid & gid are not paired. */
/* Notice the -exec runs another command on the found file. */
sudo find / -group 20 -exec chgrp 211 {} \;
On the Mac you get into single user mode by holding down command-s when you poweron your machine. Just in case you run into problems.
On Mac OS, there are a few files that have the old uid as part of their names. The .Trashes file will be only removal media and maybe everywhere.
/.Trashes/501
/Library/Caches/com.apple.IntlDataCache.501
/Library/Caches/com.apple.IntlDataCache.sbdl.501
/Library/Caches/com.apple.user501pictureCache.tiff
On Linux, there are a few files that have the old user name as part of their file and folder names:
Here is another explaination of the procedure. ( It misses some file because the auther checks only the most likely places.
http://lissot.net/netinfo/change_user.html
Robert