SUMMARY
When attempting to set up a NAS or network share for backup using the "Protect a NAS" feature, the setup will fail if the NAS name or share name contains a space.
ISSUE
Problem:
Attempting to add a NAS mount for backup protection using the "protect a NAS" feature fails, or, attempting to add NAS storage for use as a disk device fails. The network path to the NAS mount contains a space. For example "\\server\share name" or "\\server 1\share" will fail.
Issue:
Though UNC specs do support spaces in the full path, and Unitrends can back up paths containing spaces and many other special characters with no issues, the hostname is limited by DNS naming conventions (or the mount IP), and the share name is limited by SMB/CIFS or NFS specifications which themselves do not support spaces in the share name or mountpoint designated. Spaces in share names were supported under NetBIOS which is why several vendors continue to allow shares to be created with them causing some conflicts. Attempts to register a share for backup protection or to be a disk device will fail if the DNS name or mount name contains a space or other characters that deviate from industry specifications.
Shares with spaces in the host name or share name are not supported for backup or for use as cold copy targets or backup storage space by Unitrends today.
RESOLUTION
Alternatively, the methods below can be used to protect the mount
1) On most NAS devices, an NFS mount can be added in addition to the existing CIFS mount (or vice versa) and may allow a different share name under the additional protocol without any conflicts to the other protocol. This is a very common configuration and easy to add in most NAS devices. Note: Unitrends Appliances will also benefit from improved backup and restore speeds when using NFS vs CIFS, and if NFS can be used it is always preferred over CIFS backups by best practice.
2) If the share is hosted on a common server OS, not a hardware NAS, install the Unitrends Agent for that server and protect the data at the OS level with file-level backups instead of using a mounted NAS share. It is always a best practice to use an agent where possible as this enables change tracking and incremental forever support.
3) Some NAS units will allow an "alias" or secondary share name to be used for the same share, if so one should be able to be created without spaces while leaving the existing share containing space in production for other uses.
4) If the NAS is a supported NDMP device, customers with Enterprise Plus UB/RS licenses can protect the NAS using NDMP. You can see in our admin guide if you NAS might be supported here
5) Change the share name to not contain a space. Although this may require planning and an outage event, such a change is usually easy to propagate to systems using GPO or other automation tools.
CAUSE
Officially supported characters for a DNS hostname are letters and numbers and the dash "-" symbol. A hostname must not begin or end with a dash, it can begin OR end with a digit but not both. These are the only supported characters for a DNS hostname. Spaces in host names cannot be supported.
Share names or mounts may additionally contain an underscore "_" in addition to the above-listed characters (but cannot start or end with one) and may also end with a "$". Other special characters are supported by some vendors, but are not a part of SMB or NFS specifications and are not expected to be universally supported. Spaces in share names are not part of SMB or NFS specs, but were part of NetBIOS support, which is why some vendors do not prevent these configurations on their NAS devices. Linux and other non-windows systems will have great difficulty connecting to these mounts if a space or other unsupported character is used.
NOTES
Sources:
https://technet.microsoft.com/en-us/library/cc959336.aspx
https://msdn.microsoft.com/en-us/library/gg465305.aspx