[Hellgo]

Hi,

I posted this over at the apple discussion board, but I thought I would post it here to see if you guys had any ideas on this.

I work for a school and we are looking into buying 90 macs for the upcoming school year, a combination of emacs and ibooks. I am also planning on getting an xserve so that we can have networked home directories so that the students can get their personal home folder from whichever computer they log into. Now I guess this shouldn't be a problem for the emacs as they will be wired in a 100 megabit network but what about the ibooks? We will be using airport extreme and I know that the OS X server guide states that you need to have 100 megabit network to use that system. Now the accounts won't be more than 50 megabytes in size. So can we use the networked home folder for them? Or will we need to use mobile accounts for them? WIll this completely saturate the network if all 25 ibooks log in at once through one airport extreme base station? OK I guess that is it for now. Any help that you guys can give would be much appreciated.

Thanks,

Eric

[Oneota]

I too work for a K12 district, and we use networked home directories for our multitude of iBook carts (30 machines/cart), none of which have AirPort Extreme, so they're all sharing 11 Mbit/sec.

Other than there being issues with all 30 of 'em trying to login at once, it works fine. You just have to log in 3 or 4, wait, then do the next 3 or 4.

Once they're logged in, reads/writes to the home directory occur infrequently enough that all the machines can share the limited bandwidth without a problem. Again, you just need to stagger intensive read/writes, so if a teacher is having all the students write a paper in Word, he/she should *not ever* utter the phrase "Okay, everyone hit Save NOW" but should rather encourage periodic, random saving.

[Hellgo]

Thanks for the response. A couple of questions for you if you don't mind:

What size have you limited the student's user account to?

We want our students to use iPhoto, do your students use it and if so do you notice that it really slows down the system?

Thanks,

Eric

[Graymalkin]

Using iPhoto over a wireless connection with more than a few users online simultaneously is going to really bog down your wireless link. Every iPhoto library consists of the data library as well as several thumbnail libraries which number in the tens of megabytes. My iPhoto database over even a 54Mbps link would take a while to just load over the network under ideal conditions. With 4 users it would take quite a bit longer. With more than ten users opening large files or generally causing a lot of steady traffic the network is going to slow to a crawl.

You might not have too severe of a problem if your iPhoto libraries are relatively small and are used mainly to organize pictures off the web and such. My library is gigantic because I take ridiculous amounts of photographs with my digital camera. If the total size of your library database and thumbnail cache is only a few MB it might work just fine over a wireless link.

[Oneota]

Originally posted by Hellgo:
Thanks for the response. A couple of questions for you if you don't mind:

What size have you limited the student's user account to?

We want our students to use iPhoto, do your students use it and if so do you notice that it really slows down the system?

Thanks,

Eric

We have quotas of 250 MB/student, but we're not enforcing them (we have an XServe RAID serving out home directories, and it's got plenty of space).

They do use iPhoto, and we don't notice that it slows the system any more than anything else. The iBooks are definitely slower than the desktop machines, because 30 kids are sucking their home directories through a tiny straw, but it's livable.

The students probably don't use iPhoto as much as the teachers do, so their iPhoto libraries probably aren't that big. That, and we just switched to Mac OS X this school year (well, July of '03), so there hasn't been that much time to build up a huge library yet.