Software Update - Should not need Reboot after installing

[benmc]

Hi all

This is my first post here so please be gentil

I work as an Oracle DBA and I work on UNIX boxes of all types on a day to day basis. Now if I need a patch appplying on Solaris the patch is applied and the server does not need a reboot.

So why with OS X having a Unix core do Software Updates like last nights Security Update require a reboot? I just cant understand it

regards

ben

 

[robbieduncan]

OSX is a consumer OS. On Solaris you can safley assume that the SA will have the knowledge, ability and sense to stop/start the effected services and ensure that this is done properly. On a consumer machine it is easier to simply stop/start the whole machine as this ensures that the effected services are now running the patched code.

Beyond loosing your uptime what have you lost be spending 2 minutes rebooting?

 

[Independence]

I've never understood why people think rebooting their machine will kill them.

Seriously, it takes my machine about a minute to boot up. I shut it down every night. I don't cringe every time I push the power button to start it back up.

 

[benmc]

I dont mind rebooting my computer.

What annoys me slightly is that every other 'nix system that I have worked on does not need a reboot after patching so OS X should be able to cope

ben

 

[Westside guy]

Solaris doesn't need to reboot?

That's interesting if true. Most every other *nix out there does if you've upgraded the kernel. This seems to be the case with OS X as well - I've seen a number of software updates come down the pike that that don't require a reboot.

If I remember I'll ask my office mate about this - he has a few dozen Solaris boxes under his management.

 

[robbieduncan]

Most updates do not alter the kernel. For example the latest Security Update altered a lot of OS level services but did not seem to change the kernel. In theory you could have just restarted all of the effected services instead of rebooting. I don't think that even Solaris can upgrade it's kernel without a reboot. On a side not most patches applied by the SAs to the Solaris boxes where I work seem to require a reboot.

 

[jxyama]

i don't think restart is an absolute necessity. i think it's sufficient to just restart all services and/or restart the kernel.

"restart is needed" is apple's short way of saying that, instead of going into details to possibly confuse consumer-level users.

 

[patrick0brien]

-benmc

This is a very good point. And this aspect of UNIX should be realized shortly. In fact, non-reboot need was supposed to be present in Panther already. But I guess that date slipped...

 

[jeremy.king]

I understand your issue, benmc, so I wonder aloud.

If you apply software updates from command line, does it still "force" you to reboot?

I mean if you are good enough to restart all affected services, certainly you are good enought to apply updates from terminal. I've never tried.

BTW, you can bypass the reboot if you have another user logged into you mac because it asks you to enter username/password to reboot and all you have to do is click cancel and the machine will not reboot. Stupid but convenient, especially if you are downloading while applying updates.

 

[bousozoku]

Well, the updates are moved into a staging area prior to re-boot. On the re-boot, while services are down, they're moved, replacing the existing files. When services are started, everything is normal again.

If Apple wanted to work a different way for advanced users, they could provide a list of the services affected by the update as the update was ready to be installed and ask the user to click to stop/install. However, it costs more money, and complication, to customise for different users.

This way is effective and provides very little trouble for everyone.

 

[Westside guy]

Re: Solaris doesn't need to reboot?

Originally posted by Westside guy
If I remember I'll ask my office mate about this - he has a few dozen Solaris boxes under his management.

I know quoting myself is a cardinal sin, but... anyway, Solaris DOES require reboots for kernel upgrades, just like every other *nix.

Also, based on my Linux experience (which may or may not directly apply) you'd be surprised at what can require a kernel update. In Linux, a change in a kernel module - say for PCMCIA networking - can also require a change in the kernel. I'm not saying this is always the case with Apple's updates; just that it might be the case more often than is obvious.

BTW you can't "restart" a kernel. The kernel is the core low-level OS - there's nothing below it that could manage a restart. If this was a true microkernel, a la GNU's Hurd (if that were actually a finished product), most kernel updates would not require a restart unless they affected the very small core.

 

[Bear]

Application upgrades/install do not require a reboot. (Unlike windows.)

OS Upgrade/patchess (and certain device driver changes) require a restart.

Whene an OS provided library changes, it's safer to reboot then to try and restart every program using the library. Especially if it's a library that user apps use as well.

 

[cpjakes]

Originally posted by kingjr3
If you apply software updates from command line, does it still "force" you to reboot?

I mean if you are good enough to restart all affected services, certainly you are good enought to apply updates from terminal. I've never tried.

Running sudo softwareUpdate from Terminal just tells politely to restart, there's no requirement. As is the case with Software Update, it'll just sit in the background until you choose Restart or Shutdown.

It's also a great time saver to run it through ssh on other machines. Then the next time a user reboots the machine, the updates are in place.

cpjakes

 

[Powerbook G5]

Generally, the reboot just helps to apply the updated patches system-wide and make sure that everything is running smoothly after a change has been made. Sure, it may be annoying to have to reboot, but my PowerBook reboots in quite under a minute, so it's not like I am left waiting for a terrible period of time.