Several people asked us – why your product is named VSS? After all, VSS stands also for Visual SourceSafe… The short answer: we were never very good at naming.
Today, VSS stands for Volume Shadow copy Service. But it was not the case in the past. Back then, at the beginning of the project, when VSS was chosen as the name of our service, it was the acronym for Volume Snapshot Service. Later, for some reason, the whole project was renamed into DSS, i.e. Data Snapshot Service. But the infrastructure provided shadow copies only at the volume level, so the product was renamed back to VSS.
Somewhere later, the keyword “snapshot” was replaced with “shadow copy” almost everywhere in our project. But VSS was already an established name internally, so we kept it. (And, if you ask me, another arguable reason was that VSCS is probably not as nice as VSS). As a curiosity, the word “snapshot” is still lingering around in very few places, like some API names.
We had also some interesting code names for various VSS components:
– Babbage was the acutal implementation of the in-box shadow copy provider. Why Babbage? Since the implementation is based on a copy-on-write approach, we imagined our provider as some sort of “differential engine”…
– Lovelace was the component that syncronized the I/O during shadow copy creation across all providers, through the IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES and IOCTL_VOLSNAP_RELEASE_WRITES (documented in the DDK). Internally, we still use the term Lovelace occasionally.
– Byron was the process used to manage and coordinate shadow copy creation across several providers. This name didn’t stuck for long.
– Timewarp – used to denote the Shadow Copies for Shared Folders/Previous Versions product.
Nowadays, people use various expressions, keywords and acronyms to denote VSS-related functionality:
– Some people used VSC instead of VSS (Volume Shadow Copy service) but the VSS team prefers one name for this service so we kindly discourage this alternate acronym.
– The Shadow Copies for Shared Folders feature is sometimes shortened as SCSF.
– The term “Shadow copy Storage” (sometimes reffered shortly as Shadow Storage or simply “storage” in the VSS context) was internally reffered as “Diff area” in the past.
In the end choosing the name VSS was probably not a bad idea. Even if there is a conflict with the other VSS (our source code control system), in the end it didn’t matter that much… probably because these two technologies are completely unrelated and used by very different classes of users.