As you can see in the subject the permissions: drwxrws--x. I'm transferring files from one server to another. One of the directories has the permissions of drwxrws--x. When I transfer it to the other server I get: drwxrwx--x. I'm using rsync to do this. I would like to know what is that s and how would I set it using chmod if that is the case. Thanks

s - Set user ID
Look at "Set User Identification Attribute" in the article link below.
http://www.comptechdoc.org/os/linux/..._ugfilesp.html

s in that position is set group ID

You can details of all the permissions by typing:
man chmod

chmod 2755 filename

Would set permissions to what you had before.

In your rsync are you using -p or -a?

I'm using -a. Can I use both: -a and -p?

-a is the same as setting many individual flags including -p so you don't need to include -p if you're doing -a.

Just hadn't really run across the SGID in my prior rsyncs so was curious if you were using it. Probably doesn't transfer SUID either for security reasons.

Now when I try to change it at the destination server using chmod 2755 filename I get:

chmod: changing permissions of `filename': Permission denied

In this hosting server I cannot use sudo or su. So I cannot change it.

I did it this way:

chmod g-x dirname
then:
chmod g+s dirname
and it works but I get:
drwxrwS--x instead of lowercase 's' drwxrws--x. Is there a difference?

You shouldn't have removed the x. The SGID is in ADDITION to the other permissions.

rwxrwsrwx = Group has read, write and execute AND SGID is set.

rwxrwSrwx = Group has only read and write (NO execute) AND SGID is set.

The upper case S is just to distinguish it from having the execute bit set.

By the way - earlier I mistakenly said "chmod 2755" - it should have been "chmod 2775".

You should be able to add the execute bit back with "chmod g+x" - if that doesn't make it go to lower case "s" but rather to "x" just do your "chmod g+s" afterwards.