To defrag or not to defrag? (non-SSD)

In support of the possibility that backups could be messed with by defragging, there were 3rd party programs that could move clusters/sectors that the OS had marked as unmovable and that the built-in defrag couldn't move. Using those programs gave a graphical display of those files, in red, and truly would allow a tighter arrangement of the files on the drive but also could skew the MFT/Master File Table which could cause issues, anywhere from minor to catastrophic.

ignatzatsonic said:

Maybe I'm not remembering correctly, but weren't there at least occasional problems with defragging apparently causing issues with images when those images were made with the built-in imaging tool under Windows 7?

As I recall, the problem surfaced when you tried to restore---everything appeared OK while making the image file, only to be disappointed when it mattered later.

True, in my experience. The 'Backup & Restore (Windows 7)' system images are notoriously 'fragile'. Almost anything can make them 'disappear' when most needed. Never had that problem with Macrium though.

jimbo45 said:

Hi there.

I'm still surprised at how this old horse (not me I hope !!!) hasn't been flogged to death yet.

Decent modern fast HDD's (SATA, 7200 RPM rather than 5400 IDE RPM) -- (SSD's never need defragging BTW --if you still think they do go back to Physics 101 and understand the mechanics (never mind the electronics) of how a data cluster (disk address) is accessed in an SSD compared with a classical HDD) don't IMO ever need defragging - but if you still think HDD's do then it's quicker by far to use a backup program such as Macrium / Acronis etc to image the HDD and then do a SMART restore --far quicker (by HOURS in case of large capacity HDD's >2 TB for example) and usually more effective.

With a VM (Virtual Machine) it's slightly different as VM files grow quite differently compared with "standard disks" - especially if you assign the virtual disk area as "dynamic" or don't assign the whole lot in one go so it can just grow as needed. Typically say you have a VM with 30 GB of disk space -- initially 2GB might be assigned and as the VM needs more it just adds it in 2 GB chunks as needed until the maximum size you've specified in the configuration for the Guest OS.

Most VM software have their own utilities for "defragging" or optimising VM disks -- this is usually worthwhile - you'll get a warning from the VM program when you need to do it and it uses its own software - and usually gets performed quite quickly.

Cheers
jimbo

From Windows 3.1 (and DOS 3.3) all the way to Windows 7 at home, Windows 7 and 10 at various schools:
-- defragging HDDs seemed to, appeared to, be a little bit helpful to 3rd party undelete utilities' recovering deleted data files
-- beyond Windows XP, I never saw any measurable performance or speed enhancement from defragging