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TOPIC: Mass MacBook Imaging Discussion

Mass MacBook Imaging Discussion 25 Mar 2016 02:08 #2227

  • John Humphrey
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Looking towards the possibility of needing to image about 3500 MacBook Airs this summer and looking at options and thought I would start a discussion.

For those of you that have gone thru mass loading of MacBooks, need some direction and opinions on options.

1-Pre Baked image or build each on fly from OS and app packages? Time difference in loading?

2-Local Thrunderbolt or network imaging? Pros/Cons of each?

Thanks!
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Mass MacBook Imaging Discussion 28 Mar 2016 14:38 #2229

  • Byron Gerber
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1. I would do a pre-baked image because you can change all the settings that you want, this way you can dial in the image to your specific needs.
2. Lighting is fast but I have never imaged near that many, so I probably don't have a good answer for that.
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Mass MacBook Imaging Discussion 29 Mar 2016 07:50 #2234

  • Pierre-Nicolas Rigal
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Lightning deploys each image way faster than netboot imaging, but you need more manipulation than with netboot - so at the end the overall time will likely be smaller with netboot (once you configured your imaging association and made sure your devices will netboot, you are more or less done).

Regarding your first question - depends on the life time of your images. If you are likely to re-image all devices in 1 year, it's maybe better to have a larger image with everything on it (keep in mind that this will go over the wire and make the process itself slower). If you plan to let those devices for a long time, it's maybe better to have a small image, and use FileWave to deploy the rest, so you can later remove unused filesets or configuration.
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Mass MacBook Imaging Discussion 24 Jun 2016 15:09 #2332

  • mguizzetti
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What is the maximum number of devices you can image over netboot at one time? 100mb or 1000mb connection. can you go cross subnet?

Mass MacBook Imaging Discussion 28 Jun 2016 08:02 #2336

  • Pierre-Nicolas Rigal
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As any performance related question, the answer will be "it depends".
Points you have to take into account:
- how is hosted your IVS, most important : how are stored images ? Is it an old 7200 Hard Disk or are you using SSDs ?
- what kind of network interface do you have ? 100 MB/s ? 1 GB/s ? Aggregated connections ?
- what is your network topology / organization ? do you have lots of traffic over the wire ?
- how large is your image ? 4-5 GB or 60 GB ?
- what's the network interface + hard disk of the devices you are using ? 100 MB/s + normal disks or ! GB/s and SSDs ?

Once images are on IVS, the process is quite simple: we setup an NFS share between the device and IVS and we use system command line tools to read the image and restore it on the device.
So the speed of a restore depends on disk speed on IVS (read), disk speed on device (write), and network connection between the two.

can you go cross subnet?


Yes, but most of the time your routers will, by default, not let dhcp and netboot packets go through ; you will have to configure them to do so, which is most of the time not what you would expect.

This is why the recommended approach is to have multiple IVS instances - both will replicate files and associations.

Mass MacBook Imaging Discussion 28 Jun 2016 15:14 #2337

  • mguizzetti
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I'm looking for a generalized answer vs unique to my configuration. Lets assume two scenarios where you have an ideal hardware configuration and 1000mb connection and another where you have the 7200HDD and a 100mb connection. What's the max number of devices you would expect to be able to image?

Does the size of the image have a negative effect on the number of devices you can image at one time or just the amount of time it takes to image a device? If it does effect the number of devices then what is the matrix (number of devices & size of image)

Thank you!

Mass MacBook Imaging Discussion 29 Jun 2016 09:27 #2340

  • Pierre-Nicolas Rigal
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You have to consider imagining mostly as file transfer. If you reach the limit of one component (server, wire, client) it will "just" take longer.
That said it's hard to give you a number - maybe some Alliance users have some experience they can share, but except if you have a very fast server (i.e SSD + aggregated connection) and slow clients, I don't expect the system to work full speed if you have several clients imaged at the same time.

Maths are quite simple:
- an entreprise HDD is usually 100-150 MB/s in read mode
- laptop HDD are way lower, usually around 50 MB/s write mode (when they reach this limit).

which means that assuming you have fast connection, with 3 devices your server HD won't be fast enough to serve everyone.
Now, if you have large storage servers, they may be even slower than this, and if you have laptops with SSDs, they will be much faster than your server, then you will never be at full speed.

So - there is not really a limit in terms of concurrent access (the only risk is that if your server is too busy to serve files, it may be too slow to answer DHCP/netboot requests and then requests will timeout). It's just that it will take more time to finish.
Same for image size - if you have more data to transfer, it takes longer.

I know it's not the answer you expected, but I can't be more specific unfortunately. As far as I know, the usual process is:
- create a very small base image, using drivers as separated filesets for windows
- use FileWave to deploy the rest of your setup. Then you don't have a 60 GB image which is outdated every 2 weeks because of updates.
- then you can start imaging 5 devices at once, and increase this number if you can see your IVS is not reaching IO limits.

but again, these days where you usually have fast but small SSDs in end user computers and large but slow HDD in servers, the balance is on the client side, and you will have to either be patient or setup a real hosting server.

That said, it's still faster than installing manually the OS on all devices, or even having to manipulate mac books to set them up via thunderbolt if you have more than 20 devices to install.

Mass MacBook Imaging Discussion 29 Jun 2016 14:49 #2341

  • mguizzetti
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Apple claims NetInstall will image 50 over 100mb connection and 50+ over 1000mb connection. It's not a direct answer; however, I think what I'm looking for is in there. Assuming there is not hardware, network, or software bottlenecks you can initiate "unlimited", 50ish per apple, imaging jobs at one time. I understand the more you image the slower it will be, I'm not concerned with the imaging time at this point; I want to be able to initiate 30 devices and walk away knowing they will complete the image.

At this time we've only been able to start 2-7 Ethernet devices at one time with random results. We are still troubleshooting the cause, we have various apple models, 100mb or 1000mb network does not seem to change the conditions. I will look into DHCP timeout and see if there is an issue here.


Thank you!
Last edit: by mguizzetti.
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