Server! v4.1.2 released

We have just released version 4.1.2 of our Server! software. This version features the following improvements:

  • Fixed: bug in retrieving the last modification date of files stored in UNC paths (SFTP protocol only)
  • Fixed: bug that prevented WinSCP from asking for confirmation before overwriting a file (SFTP protocol only)

Warning: upgrading to this version from any version prior to 4.0.34 will invalidate your license, so please if you are a customer – before you upgrade – contact us to request a license reset.

Note: if after the update you notice any unexpected behavior in the web interface, just hit Ctrl-F5 in your browser; that will force the browser to reload the page as well as all back-end scripts and update the ones that may have been cached from previous versions of the software.

As usual you can download this new release from our website.

Hiding certain files from a directory listing Server! version: 4.0.24+

As of version 4.0.24, Server! has introduced two new features:

  • the BeforeSendDirListToClient event handler
  • the RemoveFromDirList method in the scripting framework

These features can be used together to hide certain files from a directory listing. This is useful, for example, when you don’t want certain users to see certain file types when they connect to your SFTP server, but you still want to show such files to other users.

The first thing to do is creating a script. Let’s assume, for the sake of this example, that you want to hide some AutoCAD® files, and specifically all DWG and DXF files. Then you will need a script like this:

Once the script is ready, you will have to open the user profile you want to apply the rule to, and add an event handler to it, like this: Continue reading Server!: VFS with quotas Server! version: 4.0.0+

The Virtual File System (VFS) instroduced in Server! v4.0, comes with a long-awaited feature: quota management.

The Windows OS features a very powerful yet complicated quota management, but it’s only available in Windows Server editions and requires optional features to be installed, therefore we could not rely on that and we built our own quota management system which is cross-compatible with all Windows systems.

Now, the problem with quota management is that calculating the current size of a folder (along with its sub-folders) can be very time-consuming, if the folder contains millions and millions of files. So if we were to re-evaluate the size to enforce quota restrictions at every operation it could totally kill the performances. Our solution the Quota TTL, which is the Time-To-Live (TTL) of the quota cache, expressed in seconds. Basically, when Server! calculates the current size of a folder structure, it will consider such result valid for QuotaTTL seconds, without re-evaluating it too often. Continue reading

How to put users’ homes on shared folders Server! version: 4.0.5+

Some of our Server! users prefer to store their users’ home folders (actually VFSs as of version 4.0) on a different machine via shared folders. For example, instead of having your user’s home point to C:\SFTPData\MyUser you want to have it point to \\\SFTPData\MyUser.

This is a perfectly reasonable and fairly common request. As of version 4.0, Server! provides a variety of methods to accomplish this goal.

The first step is always the same: creating a VFS that points to the network-shared folder, like this:


Once the VFS is created, you can proceed and create a User profile that uses the newly created VFS as its “home”. And this is where you have many options.

For example, if your entire infrastructure runs on Windows (including the machine that shares the folder) and all your systems are ActiveDirectory-aware, then you can specify the user type as “Active Directory” and impersonate the home VFS as “this user”: Continue reading

Parametric home directories Server! version: 4.0.26+

Another highly requested feature that we introduced in Server! v4 is parametric home directories.

Some of our customers, in fact, need to isolate every user in their own directory under a general “container”, the directory name being the same as the user’s username. They also requested that if a particular user’s home dir does not exist, it is automatically created when the user logs in.

A structure like this:

This is how you do it in Server! v4. Continue reading Server! v4 Test: 200,000 files in 1 folder Server! version: 4.0.0+

We had customers reporting that Server! v3 session threads may stall (and use up an entire CPU core) during directory listing if a single folder to be listed contains a large number of files, say north of 20,000.

First we tested our v3 to confirm the issue, then we tested many other FTP/SFTP servers, and found out that none of the tested competitors passed the test either. Some of them crashed around 10,000 files, the best ones crashed around 65,000.

Then we tested our own new Virtual File System that comes with Server! v4… and, well, we think that a picture is worth a thousand words: Continue reading Server! v4: Encrypted File System Server! version: 4.0.0+

One of the most anticipated features that Server! v4 will deliver is the ability to mount virtual directories – even nested ones – as encrypted virtual file systems.


The Encrypted VFS transparently encrypts and decrypts data on-the-fly during uploads and/or downloads, making sure that the files at-rest on the server side are always encrypted. This way you can run your server externally, and still always be sure that who operates the server for you doesn’t have access to your files/backups. This is also a requirement in some cases when your company has to comply to the PCI/DSS or HIPAA regulations. Continue reading Server! v4: the all-new VFS Server! version: 4.0.0+

One of the biggest changes that version 4 will bring to Server!’s user base is the all-new Virtual File System. This is such an epic change that it’s actually one of the reasons why the release of v4 is taking longer than expected… but it will be worth the wait.

Check out the following comparison table to appreciate the main advantages of the new VFS over the previous approach (that was based on “virtual directories”):

Virtual Directory Approach (v1, v2, v3)Virtual File System (v4)
Virtual directories can only be placed directly under the user's home directoryIn a VFS, virtual folders can be placed anywhere, even nested within each other
All virtual directories are accessed "as" the user who logged in (single impersonation)In a VFS, each virtual folder can accessed "as" a different user profile (multiple impersonation)
Virtual directories mapped to UNC paths could not be accessed by "normal" user profiles, only by Windows or AD user profilesEach virtual folder has its own impersonation criteria, so even "normal" user profiles can access virtual folders mapped to remote UNC paths

Continue reading

Maintenance release: Server! v3.1.1.41

We have just released a maintenance version of Server! This new version fixes a tiny glitch that prevented the software from saving the log files in the correct folder under certain operating system locale configurations.

If your log files are saved in the right place, you don’t need this update.

As usual, you can download the latest version from our web site.