Also, using a more sophisticated predictive algorithm for creating a pool of preloaded images could substantially lower the occurrence and impact of actual load times. This is a particularly true in many educational and other environments where the bulk of the demand follows highly predictable patterns.
Sam Averitt -----Original Message----- From: Henry E Schaffer [mailto:h...@unity.ncsu.edu] Sent: Wednesday, November 04, 2009 1:52 PM To: vcl-dev@incubator.apache.org Subject: Re: Fwd: Image Loading Times Cliff writes: > I'm running image loading tests and I am noticing that it > takes about 10 minutes to load an 8 gig VCL image from the > storage appliance. My experience is from 8 to 18 minutes to load a (bare metal) image depending on the size of the image. (This is one reason to make images somewhat single purpose and to strip out what's not needed.) VMware guest images load considerably faster. > We are using a 1G backbone on the system, and some of the > people backing our test program are wondering if we can speed > this up a bit since they are uncomfortable with the 10 minute > load times. My understanding is that there are a number of factors at play, the backbone, the I/O of the disks and the computers, ... We treat this as a "cultural" issue, and try to get users to understand that they either should make an advanced reservation (very few do :-) or do something else in the 10 or so minutes. Since people are already on a computer, most of them can easily spend the time on their e-mail, web surfing, whatever. (A not-uncommon result is that they forget about their reservation and it times out before they check it. :-) The one time this wait for loading is really not acceptable is for a scheduled class - and that's the reason for the Block Reservation which allows the multiple reservations for the class to be loaded in advance so they are availble for login at the specified time. Then there is no load needed, and it takes only about a minute for the login process. > Are these speeds OK? What are you all experiencing? > > Do we need to drop a few G's on a 10G backbone? Somebody else should discuss what good this might do, and perhaps also discuss the types of disks that can be used and speeds. -- --henry schaffer
