We are about to rollout a new offering soon and we're down to the wire on whether to write a Joomla maintenance program or use a tool like JMS.

The problem for us is we use cPanel (we have our own servers) and we want to keep disk and bandwidth quotas enforced for each multisite setup through JMS.

Is this possible since cPanel does this at an account vs. domain level?

Thanks.

Sorry but I don't understand the feature that cPanel do.

All I can tell you is that JMS allows create several website on a same cPanel account.
On this account, you can define several domain and share the same joomla files and folders present on the disk.

So if for example you want to install 100 websites, with traditional method, you have to install Jooma 100 times. So the disk is approximativelly 100 * 20 MB = 200 MB.
With JMS you have on the disk only 20 MB whatever the number of website you install.

As you have a single instance of Joomla on the disk, you also benefit to reduce the maintenance as you have to do it only once.
See UserManual chapter 8 for the different update scenario.

When you create in cPanel different domain that have their own directory, you can ask to JMS deploy the website into those directory.
In this case, JMS create Symbolic Link that does not take place on disk (almost 0 bytes).

Normally you could continue configure cPanel as you do usually and just deploy the slave site into this directory.

With cPanel, you create a site account and that account (the domain name is just part of the account creation) which has disk and bandwidth restrictions.

What you don't want a single website doing is hogging all your bandwidth and disk space which gets expensive. So, the way you do that with cPanel is to create a new account tied to a domain.

That account inherits those quotas. With addon domains or parked domains, you loose that capability. The leech addon/subdomains could put you in a bad situation since there's no way to really see who's hogging resources since it would all be setup under one account.

I thought that using symlinks might solve it but the way JSM is setup is that symlinking only works within the account. You can not say symlink to a master account from another account:

/home/newaccount1/public_html (sub account)
symlink to -> /home/mainaccount/public_html (JMS install)

The only way this might work would be to change the PHP ini at the server to allow this which would open your system up to potentially system wide site hacks.

Our only other option is to consider Jentla.com which would manage all the installations of Joomla from a hosting company perspective which we are.

If JMS can't assist with this, then it's better suited for corporate intranets and educational institutions who manage their own systems.

Thoughts?

You can use JMS with several cPanel account but in this case, as you have identified it, you need to give permission to allow create Symbolic Link on disk into several account.
You may solve such permission issue with the unix group level.

With Jentla, you replicate the database like JMS do it.
With Jentla, you are not able to share the content but you have to syncrhonise and replicate the content.

So, your requirement is to have separated cPanel account without any connection between the account. If you do not accept to share the files and folders on the disk, this mean that you have to duplicate joomla PHP code like this is the actual case.

With JMS, it is alo possible to define a rule to copy of PHP files and folders instead of using the Symbolic Links.
So if the account that manage the sub-site has permission to write into the other account, you could duplicate the Joomla PHP code instead of using Symbolic Links.
See the end of the video in tutorial 13 "replication rules" that show how to copy directories instead of using Symbolic Links.
In the case of "copy", JMS only copy the new files and folders. It does not replace existing files and folders.

With JMS, it is also possible to unzip "tar.gz" files to restore directories instead of using Symbolic Link or copy.
See also User Manual section 3.3.2 page 30 "New Folders and Files".
This probably can solve your replication problem.
With unzip facility, JMS always extract the files and folders (even when they are present).
So this can replace exisiting files.

So with JMS you could also deploy complete new fresh Joomla files and folders during the website creation.
The disadvantage of this approche will be a lower level of maintenance as it will be more difficult to JMS to distribute the installation of new extensions in existing sub-sites (slaves).
The only way will consist in using the "unzip" rules that require that you prepare such tar.gz" files.
If the objective is to create "one shot" slave site and after that let the user manage the website independently. This is possible with the "unzip" rules facility. This just require a litte time to prepare the "tar.gz".
We know at least one customer that has used the method.