How Many Users Can an Online Backup Server Support?
We are often asked how to size servers, whether virtual or dedicated, for an online backup businesses. Since WholesaleBackup run’s it’s own online backup business, it has real world experience in this process and is happy to assist it’s clients in making cost effective, yet scaleable, architectural choices. Without replicating the detailed information we’ve already published in in our document entitled “WholesaleBackup Server” which can be acquired simply by contacting us, there are a few important things to consider, including disk I/O and RAM.
Disk I/O performance is the most important factor is choosing hardware, in particular the speed of the server’s storage devices for performing reads and writes with multiple simultaneous readers and writers! The graphs below clearly show that CPU and RAM are less important given how resource efficient the WholesaleBackup server software is. If you see consistently high iowait % in your CPU graphs then you should upgrade to higher speed storage or add an additional storage device and spread your users over it. Similarly, with WholesaleBackup, each concurrent backup user uses about 75MB of virtual memory on the backup server and so you’ll want to add more RAM if you see virtual memory swapping to disk.