Starting a virtual machine crashes Mac Pro (new Intel tower)

Andrew @ Parallels said:
Development team is working on Mac Pro support and fix will be available in upcoming public build. Stay tuned.
Click to expand...

The above statement should be prominently displayed on the website where the Beta download link is located.

It is unbelievably stupid and inconsiderate not to post your MacPro problem in a prominent spot on the website on the page where the download link is located. I have wasted a few hours and actually crashed my machine so that I had to do a complete restore from a backup.

I am angry and will think twice about buying the product from you. If you could not have posted a one sentence warning at a minimum, how can I expect you to provide good service after the purchase?:mad:
 
Mtu

jdifronzo said:
Simple answer: The registry fix will cause other unpredictible problems.

Nerdy answer: Fragmentation is an important part of the TCP/IP protocol. It allows us to send packets over different mediums that contains differnet MTUs. While most networks won't have a problem with 1024 (as suggested in one post) there will be a few that do. With multiple routes to the same destination, sometimes a site will work and other time it will not.
Click to expand...

This post has bothered me for a while, but I wanted to confirm my understanding before I replied. MTU is *maximum* transmission unit. It does not fix it at that size. Ethernet's max is 1500. Lowering the max to 1024 for compatibility within XP will not prevent anything from working. It will simply cause some media (e.g. ethernet) to fragment quicker, thereby adding packet overhead, and a little slower operation.

The Internet Protocol readily fragments packets that start with a higher MTU than the subsequent link supports.

As such, the downside to making this change is that you add some packet overhead, but it won't stop data links from occuring. Indeed, quite to the contrary, it actually helps it work in this case.
 
stormj said:
This post has bothered me for a while, but I wanted to confirm my understanding before I replied. MTU is *maximum* transmission unit. It does not fix it at that size. Ethernet's max is 1500. Lowering the max to 1024 for compatibility within XP will not prevent anything from working. It will simply cause some media (e.g. ethernet) to fragment quicker, thereby adding packet overhead, and a little slower operation.

The Internet Protocol readily fragments packets that start with a higher MTU than the subsequent link supports.

As such, the downside to making this change is that you add some packet overhead, but it won't stop data links from occuring. Indeed, quite to the contrary, it actually helps it work in this case.
Click to expand...

stormj you are correct. However, the problem with the registry fix isn't setting the MTU, it is in disabling Path MTU discovery.

Let me try to explain: When you send a packet that is 1500 bytes, it travels through the internet over different mediums. If it reaches a router that requires it to fragment a 1500 byte packets that router sends an ICMP packet back to your computer informing it to lower the MTU. A host that honors this, will increase throughput over that route. Disabling PMTU stops this normal behavior, thus reducing your throughput. In some cases (altough a small number), that upstream router refuses to fragment requiring you to reduce your MTU. In that case, you will not get any traffic to your host.

Hope this clear up my prior comment.
 
RB7 said:
Sorry for the stupid question, but when you said 3-4, did you mean days, weeks?:confused:
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He was referring to the post before his that listed possible time frame. #3 was 1 week and #4 was 1 month. So it should be between 1-4 weeks until there is a public fix.
 
Tim Surgent said:
1. Open Applications->Utilities->Terminal
2. Run the following command:
Code: 
sudo nvram boot-args="-legacy maxmem=2048"
3. Reboot your Mac Pro.
Click to expand...

Like others I tried this but it didnt work. After experimenting I managed to get results by setting the value to 4096. WinXP SP2 and its updates installed but I had a crash on installing the update to .NET 1.1 (I think thats the latest version), but after restarting the virtual machine everything appears to work. Windows Update says the .NET update worked.

My main reason for using Parallels is to video chat on MS Messenger, so I was a bit miffed that the webcam isnt supported (I have both a USB and iSight available), so I hope this will get corrected by the time the release version comes along.

Victor
 
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Will parallels break when ....

It would seem that by the so called workarounds that the problem may be the 64bit support on the new mac pro's.

Right now I have a macbookpro that has a core duo chip in it and parallels is awesome, but on my macpro no dice.

When Apple decides to upgrade to the core duo2 in the mac book pros wont parallel's also break on those new machines?

Is this a symptom of apple not having proper development boxes of their new machines due to developers burning them by releasing pictures and code etc when they get a dev box.

I know some people are mad that the software crashes on mac pro's but could this be more of an issue that the developers didn't have a mac pro to try until everyone else got one?

This may be a bigger issue of the actual idea that Apple make a proper developement platform using the intel processor virtualizer so that new code can be tried on intel pre release chips?
 
Actually you can replace the core duo chips in Mac Mini and iMac with core 2 duo and they will still work. But Mac Pro is a completely new beast and completely 64-bit system architecture, so some drivers are definitely different.


wad said:
It would seem that by the so called workarounds that the problem may be the 64bit support on the new mac pro's.

Right now I have a macbookpro that has a core duo chip in it and parallels is awesome, but on my macpro no dice.

When Apple decides to upgrade to the core duo2 in the mac book pros wont parallel's also break on those new machines?

Is this a symptom of apple not having proper development boxes of their new machines due to developers burning them by releasing pictures and code etc when they get a dev box.

I know some people are mad that the software crashes on mac pro's but could this be more of an issue that the developers didn't have a mac pro to try until everyone else got one?

This may be a bigger issue of the actual idea that Apple make a proper developement platform using the intel processor virtualizer so that new code can be tried on intel pre release chips?
Click to expand...
 
rinconj said:
Actually you can replace the core duo chips in Mac Mini and iMac with core 2 duo and they will still work. But Mac Pro is a completely new beast and completely 64-bit system architecture, so some drivers are definitely different.
Click to expand...


Just to double check, you have done this and parallels works in native 64bit mode on the merom chip?

I think not.

It may be a direct drop in replacement, but the problem is with the code in parallels not the os or the motherboard.

Try no to discmiss anyone's comments without knowing what you are talkign about.
 
I was not trying to dismiss your comments. I was simply saying Parallels can try their code on core 2 duo chips months before Apple released Mac Pro if they really want to.

wad said:
Just to double check, you have done this and parallels works in native 64bit mode on the merom chip?

I think not.

It may be a direct drop in replacement, but the problem is with the code in parallels not the os or the motherboard.

Try no to discmiss anyone's comments without knowing what you are talkign about.
Click to expand...
 
rinconj said:
I was not trying to dismiss your comments. I was simply saying Parallels can try their code on core 2 duo chips months before Apple released Mac Pro if they really want to.
Click to expand...


Sorry rinconj, too much coffee this morning I guess.

I went back and re read your post and yes they could replace a chip on a mini with a merom adn test their code, hopefully htey are doing this as we speak, nudge, nudge, wink, wink.......

Or maybe not, hopefully they are fixing hte mac pro problems ;)
 
okay so at the next release Parallels will be totally sorted for me. this is great news.

Now I need to go bug Crucial for my 4 gigs of RAM so I can run multiple VMs.

thanks very much for keeping us updated.

Steve
 
I'm Ready

Ok, I have 16GB of RAM installed and I'm ready for the new release of Parallels. I have the "-legacy" boot option working a little but I don't seem to be able to get more than one VM going at a time.

I have about 5 different operating systems waiting to be installed. I'm excited now...send me betas!
 
Jeff A said:
One other thing I did, which I had to do again a few minutes ago, was to manually toggle the MTU for the built-in Ethernet on the OS X side. Use the System Preferences -> Network. For Show drop-down select Ethernet 1 (or whichever one you're using), click on Ethernet tab. Change Configure from Automatic to Manual (Advanced). Click on the Jumbo MTU radio button, click on Apply Now. Then click back on the Standard MTU radio button, click on Apply Now. No idea why, but this appears to allow XP to work properly. This worked while the VM was running.
Click to expand...


Thank you - Thank you. I've been going round and round, trying all the fixes posted, and yours was the only one to work. Bravo!!!!
 
Does the Parallels team have an update for us on the progress of the fix for the mac pro?

We are eagerly waiting.
 
Andrew,
I will be getting a purchased copy of the Parallels Desktop in the mail soon. I have a MacPro. Should I install the purchased copy over the beta trial version (not run it because of the crash)and then update when the fix is in (no pun intended)?

What do you recommend?
 
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