Disqus - Latest Comments for jeckhart

Re: Brennan & Emin Talk About Computer Science

John Eckhart — Mon, 19 Aug 2013 18:26:07 -0000

Excellent article. I've been following your series from JITR to Wayland and now this. I have one question, how do you manage deployments that include changes to your schema/data model? Can you deploy (and rollback) schema changes as part of the standard six minute deployment or are these treated differently?

Re: Time Is Marching On… Disabling TimeSync, Completely.

John Eckhart — Tue, 06 Oct 2009 12:40:46 -0000

Under what situations would I want to disable TimeSync?

Re: Solving the Chicken and Egg Problem With .flp

John Eckhart — Tue, 28 Jul 2009 18:22:56 -0000

But WHY is the flp better suited than the ISO? Is there a method to your madness?

I have used both in the past to get around various "quirks" with ESXi, VMWare Server, and Workstation. So why would you choose one over the other?

Some thoughts:
* Availability - On Windows, they both require a third party program to create and on Linux neither requires a third party program (as the utils are part of most distros). Between .flp and .iso it's a tie
* Ease of creation - A .flp needs a filesystem before you can dd it, so it's either specialized apps in Windows or loop mounting in Linux. For the iso, again, you're going to need an app in windows or mkisofs in Linux. At the end of the day, I think these are equally easy (or equally difficult for those "half-empty" folks )
* Modification - A .flp can theoretically be modified again and again, an ISO is (usually) readonly. While it begs the question of whether the image SHOULD be writable in a hardened environment, I would give the adv to .flp
* V2P - A floppy image can be written to a physical disk using dd or any number of other tools. The ISO can be burned to a CD just as easily. However, since it's becoming increasingly rare to find a computer with a floppy drive and AOL stopped sending me those diskettes a decade ago, I'll give the adv to the ISO.

At the end of the day, I think it's a matter of preference ... can you give any specific examples where one is better used than the other?

Re: Help! I Snapshotted My Datastore Into Oblivion

John Eckhart — Thu, 23 Jul 2009 17:51:56 -0000

While I assume this is a "what-if" example crafted to demonstrate a point, it is also a good intro into a discussion about a company's VM governance and policy:

* Why aren't your VM's (including the datastores) sequestered based on role and SLA? You should never see "pet VM's" on the same (virtual) hardware as production systems just as you would never have them on the same as you wouldn't have them on the same vnet.
* Unless your customer is a CS hosting provider, why are you running CS on your production equipment?(put it under your desk on that p3 they haven't scrapped yet)
* Even if you are hosting for a customer, wouldn't it still be wise to sequster your internal systems (billing, payroll, etc.) from your hosted systems?

Aside from the questions regarding VM governance, could you touch more on why you're critical of snapshots? They give you a good way to start with a vetted canned image of (something) and differentiate it as necessary. We've used them in addition to strong backup policies to facilitate recovery on systems rated for developers and testers who frequently need to step back to a golden version when things go south.