Just after clean Debian Jessie Linux installation, you will install SSH Daemon and then you will encounter an issue when you are not able to login via SSH with root account.

$ ssh root@10.1.1.1
root@10.1.1.1's password: 
Permission denied, please try again.

Sometimes after correct installation of Veeam Powershell Snapin, attempt to load snap-in into Powershell console ends with error: Add-PSSnapin : The Windows PowerShell snap-in 'VeeamPSSnapIn' is not installed.

This problem occures because for some reason Snap-in is not got registered in Powershell. On Veeam official forums they offer many solutions like reinstalling Veeam or reboots-reinstalls of the Powershell module. In my case the following solution was found:

As you know, Lync have its own address book (AB) that downloaded by clients. By default, the download and update process of address boook in Lync 2010/2013 triggered in first 60 minutes (random time) after program start. In our company this situation was considered as wrong, thus I had to find solution how to ensure guaranteed updating of Lync address book right after the client starts. Also, there are other issues with delta-updating of address book, like a big delays (5-10 days) after changes in Active Directory are repliacted to Lync AB. 

The consequences of such behavior:

Here is SELECT statement to find duplicates in SQL table on certain fields: