Known Issues in Backup
Lindenberg Software Backup limitations on Windows 7 / Windows Server 2008 / Windows Home Server
- On these operating systems the Virtual Disk API does not support all the features required by the backup service and thus the option to run a backup service is not available in the configuration UI. On the same operating systems and also because of limited operating system support for virtual disks plus lack of support of Server Message Block 3.0 encryption, the "Mount" button is not supported. Otherwise they are supported as clients.
Major Issues (these are very likely going to be addressed soon)
- USN Journal is not supported with ReFS yet. Because of that, backing up large, non-SSD ReFS volumes is a time consuming operation. With SSD, ReFS is still very practical, and in particular recommended for use with Hyper-V.
Minor Issues (these are likely to be addressed depending on user's needs. Some are just noteworthy and not really bugs)
- When backing up multiple disks, the display in Lights-Out 2 is not correct after the first backup finishes. The problem is fixed in Lights-Out 3, which also shows the disk backed up in the backup list.
- Systems using Instant Go (formerly known as Connected Standby, and also called Modern Standby in Microsofts documentation) may go to sleep state during backups, especially when running on battery. When connected to power, backups usually succeed.
- Occassionally Windows Task Scheduler may not start the backup at the configured point in time but later. The exact situations are probably only known to Microsoft, but usually it happens on battery if the battery is already low and there is a great risk that backup would not succeed anyway.
- There is no support for scheduling multiple configurations on the client, e.g. for different disks or different servers. Note however that multiple disks are supported and multiple servers are possible via Resilience Setup. Actually multiple configurations can be done with some scripting, please let me know if you are interested.
- There is no integrated means to pause a backup schedule during e.g. vaccation.
- Backup remembers the sector size of your disk only if you use .vhdx as the backup image format - which is the recommendation anyway. It also does not yet verify the target disk on restore is using the same sector size as the original. Fortunately most disks and in particular SSDs are sector size 512 bytes even though some of them use 4KB sectors physically, but unfortunately the sector size does matter. If you backup a 4KB sector size disk to .vhd, you will not be able to mount the image or start a virtual disk. This is a limitation inherited from the .vhd file format which just does not have any means to store the sector size.
- There is no user interface to change the default configuration of virtual machines. Of course you can change them manually using Hyper-V-Manager. It is also possible to use Powershell configuration scripts via the registry - let me know whether you are interested.
- Virtual machines may become broken as backups are merged, and virtual machines created by Backup are not cleaned up automatically.
Technical limitations of Lindenberg Software Backup
- Volumes larger than 256TB using NTFS, 280TB using ReFS at 4K cluster size, or 4PB (Petabyte) using ReFS at 64K cluster size are not supported. In detail: the maximum volume size supported depends on the cluster size used. Lindenberg Software Backup supports up to Int32.MaxValue*32 = (231-1)*32 = 68,719,476,704 clusters. With a cluster size of 4KB this translates to roughly 280TB. Note however that NTFS does not support volumes larger than 256TB at all, and also uses a default cluster size that increases with volume size, see Default cluster size for NTFS, FAT, and exFAT). With ReFS there is only a choice of cluster size 4KB (default since Windows Server 2016/Windows 10) and then volume size limit roughly 280TB, or cluster size 64KB (default with Windows Server 2012) and then volume size limit roughly 4PB. Note that Microsoft recommends 4KB clusters, and that with very large disks it may be more adequate to use a file based backup instead of image based backups (though I am using my own backup to backup a 2TB NTFS data disk).
Bug Bounty ProgramI am very serious about quality and specifically security of my products and services. Thus in line with others (see https://en.wikipedia.org/wiki/Bug_bounty_program) I am willing to give away free or reduced cost licenses to users who report serious issues. Eligibles have to be the first ones to report the issue (in other words, everything listed at Known Issues does of course not qualify, as does anything that is documented on this site), the issue must be serious (with respect to the purpose of the application), and the reporter must provide sufficient information to make it reproducible and fixable. If multiple users report the same issue, it is up to my discretion who will be honored, considering who was first and who was providing the most useful information.
Reports shall be sent to firstname.lastname@example.org.