Note: For a guide (non-version specific) on how to create a new Disk Pool that utilizes a NAS or Network Share as the target device (the backup directory parameter) please read the article here.
Notice: There are two ways to set the required DataCenter services to run as a particular user that has full read/write access to a network share path, instead of the default user that the services are installed clean as which is always "Local System". The easy / recommended (preferred) method of changing the Log On As for all required service needed for DC 9.x, is to directly edit each backup server enabled node (normally only backup server enabled nodes need particular Log On As user set on the DC services, but there are also reasons why certain basic client nodes may need to have the Log On As set to a different user other than the default Local System user, such as utilize a particular user for SQL Server backups, etc. instead of using the Local System user for that) via Nodes Management, and use the "Configure service account" function there to specify the user which will automatically set all of the required services to run as that user, or you can set the Log On As value manually by editing each of the services listed above on each backup server node manually via Windows Services (services.msc). It is always recommended that you first try to utilize the "Configure service account" function via the Nodes Management dialog in v9.x, per each backup server enabled node that requires it, and if that does not work you continue reading this how to article to know how to set all of the required DC services to set the Log On As user manually on them.
DataCenter 9.x utilizes a "Log On As" user of 'Local System' by default for all of its own installed services (no matter what the node type is, so for a basic client, a backup server enabled client, or a Command Server), unless you are upgrading from an 8.x version and had already specified the services Log On As setting prior, in that case it should retain the old services Log On As settings during the upgrade; however there is an issue currently with all versions of 9.x whereby one service "NovaStor DC Remote Command Executor" will always reset the Log On As user back to the default 'Local System' user after upgrade installs from v8.2.x, instead of keeping your existing custom defined user on that one DC service if you did have one defined on that single service, and you also have to know that DataCenter 9.x installs an additional new service that did not exist in any version prior, named "NovaStor DC Backup Service", seen here on a DC 9.1.5 Command Server machine when viewing services.msc:
Due to older 8.x versions not containing the above single new DC Backup Service service prior, upgrading from DC 8 to 9 does not know how to set that additional service Log On As setting to match your other 3 services that did have a non-'Local System' user defined on those services prior to the upgrade from 8 to 9.
If you will utilize a NAS device or other type of network based storage location as either the source UNC network path in your file set selection for a file backup, OR the destination UNC network path storage location for DataCenter to backup to, then you will likely need to follow these instructions on how to specify the 4 x DataCenter 9.x services to run as that user that the network device is configured for, to apply to any Backup Server enabled node (by default the Command Server is enabled as a Backup Server, but you could have many other client nodes enabled as a Backup Server in addition to that) which utilizes a Pool that utilizes a network location for the destination path for the Pool that is a protected share. Because DataCenter utilizes 'Local System' user by default to run all of its services, across all node types, know that 'Local System' is not going to be recognized for Linux based file systems and the UNC path you are utilizing is not likely to be open to everyone and is likely protected with permissions even if it is a Windows file system / file share, if you do this it is most likely that due to the UNC path (file share) for source file set selection, or the target UNC path network location to backup to will not allow DataCenter to talk to it, at least to have full write access to it. Without assigning the 3 x DataCenter services to the particular user that is added to the source share (whether that be a Linux network share, server system or NAS, or a Windows network share, server system or NAS), and since all of the services will be running as "Local System" by default without you changing it, then the failure to either backup from a network share based file selection (UNC path in the backup job) or the failure to write to a network share (UNC path assigned to a disk pool) will likely fail unless that share is wide open to everyone for read/write access. For instance, we see most people that utilize NAS devices with DataCenter need to have this set otherwise they won't be able to even add the NAS to a Disk Pool to be utilized as a backup destination, since the service(s) that DataCenter uses are running as 'Local System', the NAS device does not know what 'Local System' is and will deny access to it. Unless the NAS is fully wide open to the public, meaning no restrictions, then you will need to do this step. You will need to know what username and password is utilized by your NAS / network storage device to allow for full read/write capability which DataCenter will require for backups to store to that network location.
First of all we need to create a user that matches the username and password of the network location such as a network share or NAS device. The user can either be a local user created on the backup server node in question where the disk pool exists that points to the network device location via UNC path, or it can be a domain user, in either case that user needs to be added to the Administrators group on the local machine containing the disk pool where the disk pool exists for the backup server node. If that is not in place then the DataCenter services that talk to the NAS device, via whatever node contains the disk pool that connects to the NAS device, won't be able to have appropriate admin rights to talk to the NAS. Since by default all DataCenter services utilize 'Local System' user for the Log On As user property, the NAS or other network device probably won't know what that 'Local System' user is to get enough access to write to it.
In this example when looking at our Buffalo NAS we already have a local user on the NAS named 'admin', and so we now need to create a local user on the backup server enabled node (Windows machine) in question, as 'admin' using the 'lusrmgr.msc' command in Windows on that backup server node. If the backup server enabled client node where your disk pool is that talks to the network device via UNC path acts as a Domain Controller then you will need to create that user instead using the Active Directory Users and Computers app. The Disk Pool located on the Backup Server node in question is what communicates to the NAS device, and so in that case it needs Administrator Read/Write access to that location which it cannot obtain when DataCenter's 3 services are using 'Local System' as the user, as the NAS does not know what that user is. Creating the user this way on the Backup Server node, then allows DataCenter to have administrator access to the NAS device to store backups there. It may be best practice to create a new user on the network device, like the NAS in this example, which will never be touched or utilized by anything but DataCenter, in that case you may want to create a user "Novastor" or "DataCenter" on the network device and on the backup server node that talks to that network device (in the Users area of Windows), which contains the same exact username and password on both ends. This will possibly help in environments that enforce password changes for users accessing the network device. In this case you could never provide the credentials to anyone for this special DataCenter only user, as if the password ever changes on either end it will cause backups to fail. Make sure that on the network device end, like the NAS in our example, that for the user you set the 4 x DC 9 Services to Log On As, that same user on the NAS that is in place is added to the Administrators role on the NAS itself, and that user has R/W access to the Shared folder in question where your disk pool is pointing to utilize via UNC path.
In this example we utilize the 'lusrmgr.msc' command (or the 'Control Panel > User Accounts > Manage User Accounts > Advanced > Advanced > Users > New User') function to create a new local administrator user, named 'admin', then we tell it "Password never expires" and then assign it to the Administrators group by clicking on "Member Of" tab and add that user to the Administrators group. The user is required to be in the Administrators group as 1 out of 4 of DataCenter 9's services requires that to be able to start the service, 'NovaStor DC VM Backup Server' service (the executable for that service is 'nbksrv.exe'). Please verify the user you are creating is in the Administrators group (that being either the local Administrators or Domain Administrators group, depending on your case as DataCenter can work with either).
This is how all of the DataCenter 9.x services will look by default on a Command Server node (note that basic client and backup server enabled client nodes will contain many less services in the list but the services that are required specify the Log On As setting are the same 4 x service names), take note that by default all DC services are installed to run as the "Local System" user for the Log On As setting. We will need to change that on 4 of the 9 services on a Command Server node (and a lesser number for the other node types), otherwise backups to your network share or NAS device will fail.
Note: DataCenter 9.x added a new service named "NovaStor DC Backup Service" (the executable for that service is 'nbksrv.exe'), which is installed for all node types, that did not exist in any prior versions, which will require you to set the Log On As manually after upgrading from 8 to 9; due to that service not existing prior it has no way to set itself to match your old services if for instance you had a non-default user specified for the Log On As for the 3 x DataCenter 8 services prior.
After modifying the 4 x DataCenter 9.x services to edit them to change the Log On As setting on, it will look like this:
And this is how the 4 x DC 9 services look on a Backup Server enabled client node (not a Command Server node), you can notice how the same 4 x DC 9 service names apply to the Command Server above, and to the Backup Server enabled client node below, for the services that need to have the Log On As setting changed. Note that the first service that is selected and highlighted in blue in the screenshot below is the new service that DC 9.x introduced (DC Backup Service). Also note that in this example the Backup Server enabled client node that we are assigning the 4 x DC 9 services to a different Log On As user which is a domain user this time, as opposed to a local .\admin user in the prior example, hence why it shows the @ symbol after the domain user, but in other cases a domain user may contain the Domain\ in front of the user:
Now double-click on each of the above 4 services, and click on "Log On As" and specify that username and password (and domain if needed). Most NAS type network storage devices are not configured with Active Directory and so they utilize local users, created on the NAS device itself, so in that case be sure to leave the Domain Name field blank. If the network storage device, such as a NAS, has been integrated with a Windows Active Directory domain, you can go ahead and specify the Domain / User / Password now on the Log On As setting for the services without having to create any user locally. If the network storage device, such as a NAS, utilizes local users and is not connected to AD, then in that case you will need to create a matching user with the same password in Windows on the machine that you are configuring the Disk Pool to use with this network storage device. Create the local user using 'lusrmgr.msc', the lusrmgr - [Local Users and Groups (Local)], command in Windows on that machine, and specify the same password as the network storage device, and then you can go to Windows Services and configure the 4 x DataCenter 9.x services displayed above to select that user and specify that password on those services so that the backup software can actually get to that network storage device.
Finally, after configuring the 4 x DataCenter 9.x services for the Log On As setting and saving the changes, you will need to restart those 4 x services that were changed and make sure that the status message after restarting each service informs you that the service was started properly. If you get an error verify the user that you specified for the Log On As setting was correct with the same password as how you created the user as. Note: The username and password here is case sensitive. Make sure to enter a blank Domain Name for the Log On As setting if it is a local account. Windows Services does not check that the password is proper until it goes to restart / start the service that was modified.