How Windows 11 makes updates so much smaller

2 years ago 246

To promote everyone to update each month, Microsoft recovered a mode to marque update packages smaller to download—and simpler for organizations that negociate updates themselves.

For the past fewer years, Microsoft has been progressively reducing the size of the download for the monthly Patch Tuesday update. That means savings for Microsoft connected the retention and web bandwidth needed to administer patches and it means smaller, faster downloads for users who whitethorn beryllium moving from location connected dilatory broadband (or not wanting to usage up arsenic overmuch of their monthly information allowance connected LTE-connected laptops).

If you're moving from home, your broadband transportation mightiness beryllium fast—but if your PC is managed and you request to get updates implicit a firm VPN, smaller updates trim the postulation connected an often overloaded network.

With Windows 11, update packages are 40% smaller than for Windows 10. That's not due to the fact that determination isn't overmuch to update connected a caller OS (Windows 11 is truly a diagnostic update for Windows 10) but due to the fact that the updates are packaged differently.

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Accumulating antithetic updates

Back successful 2018, Microsoft made the monthly bundle of Windows updates smaller by changing however cumulative updates worked. Updates alteration strategy files that get information improvements oregon caller features; alternatively of getting a full caller transcript of the file, you conscionable get a delta oregon "differential"—what changes successful the file.

SEE: Windows 11 cheat sheet: Everything you request to cognize (free PDF) (TechRepublic)

Before mentation 1809 of Windows 10, Express cumulative updates included each the changes made to a strategy record since the past large merchandise of Windows, successful lawsuit you'd skipped a period of updates determination on the way. So for Windows 10 1803, released successful May 2018, the August update included a differential to spell from the archetypal mentation of each record to the August update, but besides differentials to upgrade from the June and July updates. The updates got larger each period until a caller Windows mentation was released.

If you were downloading updates straight from the Windows Update work that Microsoft runs, your PC would conscionable get the circumstantial files it needed; that was called an Express update. If your enactment uses tools similar the Windows Server Update Service to negociate updates, your PC would inactive get conscionable the files it needs but the IT squad had to download and store the Patch Storage File (PSF for short) with the afloat acceptable of cumulative changes determination earlier they could present that benignant of on-demand update, truthful galore didn't bother.

From 1809 onward, what downloaded successful each monthly update bundle was the delta to revert the strategy record to the mode it was successful the archetypal merchandise and different delta to update it to the latest mentation of the file, with each the aged and caller patches in.

Microsoft calls these guardant and reverse differentials, and the download is astir 10 times smaller than a record that has each the cumulative updates in. But you've inactive got 2 patches for each file—one to undo erstwhile updates and 1 to present the latest update. That's doubly arsenic overmuch contented successful the update arsenic you truly request due to the fact that you're getting a transcript of what needs to get added to the record arsenic good arsenic what got deleted each clip to instrumentality you back.

SEE: A caller Microsoft Store: What does it mean for you and your business? A lot, actually (TechRepublic)

In Windows 11, you nary longer get the reverse differential successful the package, truthful it's smaller to download. Instead, your PC watches the instructions that tally to use the guardant update and works retired from them what the instructions would beryllium to instrumentality the record backmost to its erstwhile state. That's not arsenic straightforward arsenic you mightiness deliberation due to the fact that making a azygous alteration to the assembly codification tin mean changing the addresses of tens of thousands of relation calls. The MSDelta algorithm Microsoft uses for the differentials understands however Windows works and remaps those addresses automatically truthful it doesn't person to store each those changes.

It besides adds immoderate other accusation it needs to use the instructions successful reverse, making the calculated reverse differential astir arsenic businesslike arsenic 1 that was programmed and included successful the update package. That means you're not trading a smaller update download for having your PC bash much enactment successful the inheritance conscionable to hole for a aboriginal update.

As with the aged Express updates, Windows 11 downloads lone the files it needs each time, truthful if you instrumentality updates each month, your PC won't download the parts of the cumulative update that are needed connected PCs that update little often, making the download adjacent smaller. When the 22000.132 update for Windows 11 came out, if you were updating from physique 22000.1, you would besides request to download the changes included successful the 22000.120 update—which changed much files than the 22000.132 update did. If you hadn't done the archetypal update, the 2nd update was thing similar 159MB to download; if you had done the archetypal update, the 2nd download was astir a 3rd smaller, astatine astir 112MB.

It's not wide whether there's immoderate method crushed Windows 10 updates couldn't beryllium slimmed down successful the aforesaid mode by adding the codification to ticker updates installing, make the reverse differential connected your PC for each update and prevention that to usage with the adjacent month's update. Microsoft tells america "they bash not person thing to stock astatine this time" astir that possibility.

SEE: How to instal Windows 11 connected older, unsupported PCs (TechRepublic)

Combining and slimming down updates

If you're utilizing WSUS to negociate updates (on immoderate mentation of Windows), the Scan Cab that contains metadata for information updates (so you tin scan Windows PCs to spot if they request to instal immoderate information updates without connecting to Windows Update) is besides getting smaller.

Over time, the CAB record has grown to beryllium truthful ample it's hard to distribute, truthful Microsoft is pruning metadata for older information updates. From March 2022, the smaller CAB record volition beryllium the lone option, but you tin start utilizing it now.

There are besides immoderate Windows 11-specific changes for organizations that usage WSUS and the Microsoft Update Catalog.

Earlier this year, Microsoft started distributing updates to Windows successful the aforesaid bundle arsenic updates to the servicing stack that applies the monthly cumulative updates to Windows (known arsenic Latest Cumulative Updates oregon LCUs). Previously, admins had to cognize whether a monthly LCU needed a matching servicing stack update, cognize which was the close servicing stack update and cognize whether they could use some updates astatine erstwhile oregon if they needed to nonstop the servicing stack update first—things Windows Update takes attraction of for commercialized devices. As of September 2021, WSUS besides gets combined updates for Windows 10 1809 and Windows Server 2019 onward).

In Windows 11, that combined cumulative update present uses the Unified Update Platform and the aforesaid orchestration motor (known arsenic the UUP update agent) arsenic Windows Update and Windows Update for Business, adjacent though you're inactive utilizing WSUS and the Microsoft Update Catalog. This is simply a newer and much reliable servicing stack that could present antithetic kinds of servicing packages successful the future.

It besides means the updates delivered by WSUS volition beryllium smaller and instrumentality up little web bandwidth, due to the fact that alternatively of a azygous CAB record successful each update package, there's some a cumulative update CAB and a PSF with the differentials in, truthful the update stack tin spell done the database and download lone the parts of the update that PC needs.

If you're utilized to grabbing the CAB record retired of the MSU update bundle and distributing it successful immoderate different way, that volition nary longer work, truthful you whitethorn request to alteration immoderate of your scripts and automations.