Using iSCSI drives with Syncrify

Using iSCSI drives to hold user repositories in Syncrify server is discouraged. This is because the Syncrify server is an I/O intensive process. During heavy load, Syncrify server will create many threads. Every thread can potentially read/write data from the disk.

Most iSCSI architectures have upper limits. Check this page to see limits for Windows 2008 server.

Additionally, since most iSCSI interfaces go over to another machine several other factors such as router, NIC cards play a big role in scalability. Although most iSCSI layers have built-in error correction, they result in I/O errors at the software layer as the number of simultaneous connections go up. Such errors create unpredictable results in Syncrify.

Symptoms

If you see File Not Found or too many EOF Reached errors in Syncrify.log on the server side and usually means trouble. There are three reasons for a file to be not found:

• File is actually not there
• The OS won't allow access due to permission problem
• The OS cannot see the file due to a network error, provided a network is involved

The first two problems can be easily discovered because they will be persistent and will occur every single time. The third one, is not very easy to detect. This is because these sort of errors do not occur every single time.

Recommended Approach

Consider using internal drives that are either SATA or SAS 3. Since these drivers do not involve any network, the scalability improves significantly.