On Sun, Oct 21, 2012 at 2:39 PM, Greg Freemyer <greg.freemyer@gmail.com> wrote:
On Sun, Oct 21, 2012 at 3:30 AM, ellanios82 <ellanios82@gmail.com> wrote:
Hello SuSErs
Virtual Machines
Could it make sense to PREFER to run Linux as a Virtual Machine?? { thus, for example, one might install openSuSE 12.2 as ones foundation, and Next, install a Virtual Machine, then, Finally install another instance of openSuSE 12.2 on ones Virtual Machine upon which Virtual Machine one would do ALL ones work}
thanks
best regards Ellan
The instant VM snapshots do NOT make redundant copies of the data. Thus
instant backups protect from user errors, etc.
do NOT protect from hardware failure
So it depends why you're making backups. I would say many of us worry about disk failures, etc. For that you need to get your full backup onto alternate media.
When I first started developing software, my thesis supervisor told me I should always aim to make my software idiot-proof since I can never know what kind of idiot is using it. When it comes to statistics, that could never be more true, given how often I have seen even full professors recommend the wrong statistical analysis. It takes a lot of effort to design your software to protect users against innocent mistakes, but you can't always protect them from 'stupid' syndrome. But I digress. It seems to me that such VM snapshots, taken immediately prior to installing new software (particularly from a source with which one has limited experience, is a good precaution against installation script that behave badly (ever seen the chaos wrought by a bad one of those?). Similarly, taken on a regular basis it serves to protect against PEBKAC. A colleague of mine protected his team against just such a thing by configuring automatic backups: a new team member wrote a badly behaved customer program that not only produced nonsensical results, it over-wrote the original data which had cost many tens of millions of dollars to collect (the fool responsible ended up teaching statistics at a midwestern US college that deserves to be un-named). When my colleague got a panicked call in the early hours of the morning while he was on the other side of the planet, he looked at the results the bozo produced, his program program and made his diagnosis; and then told his team how to recover the original data from the backups, and then he did the analysis that the other fellow was supposed to do but who messed up so badly. he also advised against trusting the bozo with anything of real value - put him where he can do no further harm. Had he used a VM snapshot, though, recovery of the data would have been much, much simpler and faster. That said, since such a snapshot is just a (very large) file, it can easily be copied to a CD or DVD (better, multiple such disks, ultimately stored in different locations) What would worry me is that someone might get the notion that such a thing is a magic bullet. As you pointed out, it has both its uses and limitations, and thus can only be part of a systemati, comprehensive design, involving multiple elements, such as a decent RAID (perhaps using hot swappable SSDs, tape or optial backup media, rationally designed user permissions, redundant servers, &c., &c., &c. To the OP, I would give a qualified affirmative answer, but advise not to forget all the many other aspects of security: system, data, &c. Cheers Ted -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org