totally reliability or speed or?
Posted: Sat Nov 28, 2015 5:16 pm
If people are interested, we can implement a old method of detecting changes
for both backup and restore that can be much faster but it is more
unreliable. It may be "good enough" for clean file systems but overall,
it's NOT "totally reliable". It would work for most cases, but you could
be burned by it, and has a chance of snowballing corruption (into your
backups) when using it for restores without you knowing it (e.g. thinking
you had a clean state after restore but really don't) .
It is the old method of using metadata to determine if changes may have been
made (e.g. dates and times, file locations (not needed for pure file based),
etc..). This method for backup and restore has been around since the DOS
day. It expanded to images (rather than pure file based) in the late 1990s
early 2000's as part of the deduplication movement; particularly to those
who wanted to provide services across slower links.
While the write tracking method recently added is not totally reliable, it's
a step above metadata. Before adding additional new options, new products,
or new companion programs based on metadata, we wanted to check to see how
much interest there would be in our user or potential user base for either
backup or restore or both. Do note that restoring using metadata should NOT
be used for disaster recovery (corruption, unexplained problems, hardware
failure) but more for, I have an image from x days ago and I haven't done
anything other than install or uninstall something that needs to be "undone"
(which to me seems more like a job for a "goback" or "rollback" utility
which is different than disk imaging). (side note: if you use one of these
along with disk imaging (being compatible), indicate what you use and how
well it works).
Don't worry, the totally reliable disk imaging methods won't go away, there
are way too many very important systems all over the world that rely on it.
Just making some decisions on 2016 (there are a lot of things that *could*
happen).
for both backup and restore that can be much faster but it is more
unreliable. It may be "good enough" for clean file systems but overall,
it's NOT "totally reliable". It would work for most cases, but you could
be burned by it, and has a chance of snowballing corruption (into your
backups) when using it for restores without you knowing it (e.g. thinking
you had a clean state after restore but really don't) .
It is the old method of using metadata to determine if changes may have been
made (e.g. dates and times, file locations (not needed for pure file based),
etc..). This method for backup and restore has been around since the DOS
day. It expanded to images (rather than pure file based) in the late 1990s
early 2000's as part of the deduplication movement; particularly to those
who wanted to provide services across slower links.
While the write tracking method recently added is not totally reliable, it's
a step above metadata. Before adding additional new options, new products,
or new companion programs based on metadata, we wanted to check to see how
much interest there would be in our user or potential user base for either
backup or restore or both. Do note that restoring using metadata should NOT
be used for disaster recovery (corruption, unexplained problems, hardware
failure) but more for, I have an image from x days ago and I haven't done
anything other than install or uninstall something that needs to be "undone"
(which to me seems more like a job for a "goback" or "rollback" utility
which is different than disk imaging). (side note: if you use one of these
along with disk imaging (being compatible), indicate what you use and how
well it works).
Don't worry, the totally reliable disk imaging methods won't go away, there
are way too many very important systems all over the world that rely on it.
Just making some decisions on 2016 (there are a lot of things that *could*
happen).