Are there any database server hardware recommendations?

First the database vendor's minimum hardware requirements must be met. Please consult your database vendor for their documentation. For the built-in EventSentry database, the vendor is PostgreSQL and the hardware recommendations can be found here: https://wiki.postgresql.org/wiki/Database_Hardware

The disk subsystem is one of the most crucial components of the machine that hosts your database. If you have slow Disk I/O then your database writes and queries will almost always be slow, even when you have ample CPU power and memory available. The ideal disk subsystem should be similar to this:

The more disks you can provide for the database partition, and the faster the disks, the better the query and write response time will be. Insufficient Disk Write I/O can cause data to queue on the agent and can even lead to an agent crash if the agent runs out of available system memory for data queues.

In environments with a large amount of events collected per minute, even database servers which meet the recommended specifications can have insufficient Disk Write I/O for the EventSentry database or transaction logs if the EventSentry disks are shared with other write-heavy databases or applications. For this reason it is especially NOT recommended to install the EventSentry Database on a mail server, such as a Microsoft Exchange server or Microsoft SBS Server.

Disk Write I/O performance can be monitored by the performance counter "PhysicalDisk\Avg. Disk sec/Write" and "LogicalDisk\Avg. Disk sec/Write" and acceptable performance levels would not exceed 0.015 for longer than 5 seconds during normal database activity. For more information about configuring performance counters in EventSentry: https://www.eventsentry.com/documentation/help/html/configpackageshealthperfcounterconfigwindows.htm

If you would like to test your database server's Disk I/O prior to configuring an EventSentry database, you may use Microsoft's DiskSpd utility, regardless of the type of database you plan to utilize. For download and usage information regardling DiskSpd, please see: https://blogs.technet.com/b/josebda/archive/2014/10/13/diskspd-powershell-and-storage-performance-measuring-iops-throughput-and-latency-for-both-local-disks-and-smb-file-shares.aspx