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7 Replies Last post: Nov 2, 2007 11:20 AM by LoCInuyasha
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CRC errors when transferring files within VM-ed environment - Halfway solved

Nov 2, 2007 11:20 AM

Click to view LoCInuyasha's profile Lurker LoCInuyasha 5 posts since
Oct 31, 2007
I'm hoping that someone will have a solution for me.. I'm sadly close to wit's end with this one.. First off, rough details:

My terms may be different than what's expected, so bear with me..

My host OS (The primary one on my PC) is Gentoo Linux.

I am using VMware Server, 1.0.3.44356

I am using this to acces a Windows 2000 virtual environment, as the company requires my using some Windows-only applications..

One of the things we need to do here, day by day, involves connecting to various shops (I run tech support here).. We use various terminal emulation programs, primarily Symantec Procomm Plus, and AlphaCom.. We often need to transfer updates to these systems using zmodem file transfers, from our computers to theirs..

Quite simply, I am finding that a small file will run into hundreds of CRC errors before transferring properly, when I'm working in the VMware environment.. Originally, I configured VMware to use the physical hard drive partition that I had Win2k installed on, using profiles to allow me to either boot directly into Windows, or to access it through VMware.. I recall reading warnings about this, so I presumed this to be my problem, and set up a new Win2k environment, entirely using the virtual disk, or whatever you'd call it, that makes VMware so great..

Sadly, the problem persists, and yet isn't there when I boot directly into Windows.. I've tried multiple new modems, as well, hoping that some manner of error correction, or different brands' Windows drivers, might help in any way..

If anyone has any thoughts, I'd greatly appreciate it.. And Happy Halloween, to all who read this thread.

P.S. I should definately mention that this problem does occur 100% of the time that I transfer a file through such a manner, and that the modem that it's transferring through is on a serial port, being passed through to my client OS. I also have not tried upgrading my version of VMware server, due to not finding any information that led me to believe it would help, and much information that implies I should wait on 1.0.4

Message was edited by: LoCInuyasha

Added P.S. rather than double-posting.

Reply Re: CRC errors when transferring files within VM-ed environment Nov 1, 2007 12:23 AM
Click to view oreeh's profile Guru oreeh 9,117 posts since
Nov 30, 2005
Moderator
Please provide the information requested in this document Read before posting questions
Reply Re: CRC errors when transferring files within VM-ed environment Nov 1, 2007 6:35 AM
in response to: oreeh
Click to view LoCInuyasha's profile Lurker LoCInuyasha 5 posts since
Oct 31, 2007

...which information are you referring to, as it is obvious that I followed that document when making my post? The exact kernel version? I'm using 2.6.22 (32bit), but have also found the same problem to occur with 2.4.10, 2.5.8, both 32bit.. As well as a Fedora Red Hat Core 5, 32bit, and my boss's 64bit Fedora Core 5.. The Win2k Guest OS is, of course, 32bit.. Win2k Professional, I guess there was that rare 64bit one that was released...

How often have I seen the problem, already stated, 100%. Worked before, no. What triggers it, see above.. Conditions where it does work, only when not doing it within VMware..

Not a network issue, so the next section doesn't apply.. I also have no real reason to believe that it's a disk issue, as the files are fine with the exception of when they're being transferred through the modem's serial port..


Reply Re: CRC errors when transferring files within VM-ed environment Nov 1, 2007 6:41 AM
in response to: LoCInuyasha
Click to view oreeh's profile Guru oreeh 9,117 posts since
Nov 30, 2005
Moderator
Getting CRC errors when transferring files over the network is almost always (99% of the time) a network related problem (network related means it could be a NIC driver as well).
Reply Re: CRC errors when transferring files within VM-ed environment Nov 1, 2007 7:10 AM
in response to: oreeh
Click to view LoCInuyasha's profile Lurker LoCInuyasha 5 posts since
Oct 31, 2007
Files aren't being transferred over a network..

I would ask you to re-read the previous post that explains, in detail, that the files are not being transferred across a network. They are not using a NIC. They are not using any manner of TCP/IP or UDP connection. This CRC error occurs solely with transferring them through a serial port modem, which doesn't involve a network...

Reply Re: CRC errors when transferring files within VM-ed environment Nov 1, 2007 7:11 AM
in response to: LoCInuyasha
Click to view oreeh's profile Guru oreeh 9,117 posts since
Nov 30, 2005
Moderator
My fault - I missed your P.S. in the first post :-(
Reply Re: CRC errors when transferring files within VM-ed environment Nov 1, 2007 7:19 AM
in response to: oreeh
Click to view LoCInuyasha's profile Lurker LoCInuyasha 5 posts since
Oct 31, 2007
Not a problem - it certainly does happen when we're reviewing a lot of posts. =)
Reply Re: CRC errors when transferring files within VM-ed environment - Solved (halfway) Nov 2, 2007 11:19 AM
in response to: LoCInuyasha
Click to view LoCInuyasha's profile Lurker LoCInuyasha 5 posts since
Oct 31, 2007

So, can I mark myself as answering the question, heh?

Anyway, I wanted to go ahead and post this, if it helps the programmers, or any other people out there...

I don't technically have a 'fix', persay, but I do believe I understand what's going on now.. Namely, the zmodem transfer was attempting to either go through the serial port too fast or, possibly, trying to transfer faster than the virtual hard drive could handle.. I don't claim to know which, just commenting for the sake of helping whoever..

By increasing my swap partition to 1gig, I sped up my system enough where the transfer would work partially, although still with a number of CRC errors.. By slowing down my modem's baud rate, I eliminated the CRC errors and am functioning more than adequately.

I hope this may help someone down the road. =)

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