7.0

Table 3‑8. Impact of Windows Services and Tasks on OS Disk Growth and IOPS (Continued)
Service or Task Description
Default
Occurrence or
Startup
Impact on OS
Disk Impact on IOPS
Turn Off This
Service or Task?
Windows Registry
Backup
(RegIdleBackup)
Automatically
backs up the
Windows registry
when the system is
idle.
Every 10 days at
12:00 am
Medium.
Each time this task
runs, it generates
registry backup
files.
Medium. Yes. Both instant
clones and View
Composer linked
clones let you revert
to a snapshot and
achieve the goal of
restoring the
registry.
System Restore Reverts the
Windows system
to a previous,
healthy state.
When Windows
starts up and once
a day thereafter.
Small to medium.
Captures a system
restore point
whenever the
system detects that
it is needed.
No major impact. Yes. Both instant
clones and View
Composer linked
clones let you revert
to a healthy state.
Windows Defender Provides anti-
spyware features.
When Windows
starts up. Performs
a quick scan once a
day. Checks for
updates before
each scan.
Medium to high.
Performs
definition updates,
scheduled scans,
and scans that are
started on
demand.
Medium to high. Yes, if other anti-
spyware software is
installed.
Microsoft Feeds
Synchronization
task
(msfeedssync.exe)
Periodically
updates RSS feeds
in Windows
Internet Explorer
Web browsers.
This task updates
RSS feeds that
have automatic
RSS feeds
synchronization
turned on. The
process appears in
Windows Task
Manager only
when Internet
Explorer is
running.
Once a day. Medium.
Affects OS-disk
growth if
persistent disks
are not configured.
If persistent disks
are configured, the
impact is diverted
to the persistent
disks.
Medium Yes, if your users do
not require
automatic RSS feed
updates on their
desktops.
Disable Scheduled Disk Defragmentation on a Windows Parent Virtual Machine
When you prepare a parent virtual machine for instant clones or View Composer linked clones, it is
recommended that you disable scheduled defragmentation. Windows schedule weekly disk
defragmentations by default. Defragmentation significantly increase the size of a clone's virtual disk and
does not make disk access more efficient for instant clones or View Composer linked clones.
The clones share the parent virtual machine's OS disk but each clone maintains changes to the file system in
its own virtual disk. Any activity, including defragmentation, will increase the size of each clone's
individual virtual disk and therefore increase storage consumption. As a best practice, defragment the
parent virtual machine before you take a snapshot and create the pool.
The following steps apply to Windows 7 and Windows 8. The steps might vary on different Windows
operating systems.
Chapter 3 Creating and Preparing a Parent Virtual Machine for Cloning
VMware, Inc. 41