6 Replies Latest reply on Jun 28, 2008 8:24 AM by vmjkx

    DISK/CDROM timeout harmful?

    vmjkx Novice

       

      I have many of the messages below in my vmware.log (VMWare Server 1.0.5 on a Linux host). The guest works without any noticeable problems. What do these nessages mean? Can I safely ignore them or can this cause data corruption? (IDE 0:0 is a virtual disk)

       

       

      Apr 16 11:33:22: vmx| DISK: DISK/CDROM timeout of 4.296 seconds on ide0:0 (ok)

      Apr 16 11:35:29: vmx| DISK: DISK/CDROM timeout of 2.902 seconds on ide0:0 (ok)

      Apr 16 11:35:34: vmx| DISK: DISK/CDROM timeout of 1.937 seconds on ide0:0 (ok)

      Apr 16 11:35:54: vmx| DISK: DISK/CDROM timeout of 1.123 seconds on ide0:0 (ok)

      Apr 16 11:36:00: vmx| DISK: DISK/CDROM timeout of 1.176 seconds on ide0:0 (ok)

      Apr 16 11:36:17: vmx| DISK: DISK/CDROM timeout of 4.089 seconds on ide0:0 (ok)

       

       

      Thanks,

       

       

      Justin

       

       

       

       

       

        • 1. Re: DISK/CDROM timeout harmful?
          Peter_vm Guru

          Yes, you can ignore those...

          • 2. Re: DISK/CDROM timeout harmful?
            vmjkx Novice

             

            Glad to hear that. Now I can sleep peacefully again. Many thanks Peter.

             

             

            • 3. Re: DISK/CDROM timeout harmful?
              jakeg Novice

               

              It may not cause any harm, but what does it actually mean???

               

               

              I get these messages all the time when something is happening on the disk:

               

               

              Jun 26 08:45:11: vmx| DISK: DISK/CDROM timeout of 1.487 seconds on ide0:0 (ok)

              Jun 26 08:45:13: vmx| DISK: DISK/CDROM timeout of 1.545 seconds on ide0:0 (ok)

              Jun 26 08:45:15: vmx| DISK: DISK/CDROM timeout of 1.887 seconds on ide0:0 (ok)

              Jun 26 08:45:19: vmx| DISK: DISK/CDROM timeout of 2.930 seconds on ide0:0 (ok)

              Jun 26 08:45:22: vmx| DISK: DISK/CDROM timeout of 1.862 seconds on ide0:0 (ok)

              Jun 26 08:45:24: vmx| DISK: DISK/CDROM timeout of 1.088 seconds on ide0:0 (ok)

              Jun 26 08:45:27: vmx| DISK: DISK/CDROM timeout of 2.462 seconds on ide0:0 (ok)

              Jun 26 08:45:31: vmx| DISK: DISK/CDROM timeout of 1.527 seconds on ide0:0 (ok)

              Jun 26 08:45:34: vmx| DISK: DISK/CDROM timeout of 2.149 seconds on ide0:0 (ok)

              Jun 26 08:45:39: vmx| DISK: DISK/CDROM timeout of 2.695 seconds on ide0:0 (ok)

               

               

              ... this doesn't look good to me at all. It seems like all the time its timed out. I can find no explanation anywhere about what these messages actually mean though.

               

               

              ide0:0 is the primary disk (not CDROM), and its Windows XP wihin Vmware Server 1.0.6 on a Ubuntu 8.04 server Linux box.

               

               

              The host is: 2.5GHz T9300 processor, 3GB RAM, 7,200rpm HDD. I have nohz=off in grub to make the 2.6.24.* kernel tickless which I read somewhere may be worthwhile.

               

               

              The guest is very slow generally to move about it.

               

               

              Any help in explaining what the message means would be great.

               

               

              Regards,

               

               

              Jake

               

               

              1 person found this helpful
              • 4. Re: DISK/CDROM timeout harmful?
                vmjkx Novice

                Hello Jake,

                 

                I've spend much time trying to solve this issue (and related issues). Problems started after installing VMWare Server on a Linux host configured with software-RAID. When there was heavy disk I/O in the Windows Server 2003 guest, both the LSI Logic (several versions) and BusLogic SCSI drivers were producing a lot of blue screens and disk I/O errors. The host and other running guests were also affected and sometimes the complete system freezed for several minutes.

                 

                Because I could not get a stable environment using SCSI, I've tried switching to IDE. My first impression was positive and all of the earlier problems had disappeared. Only "DISK/CDROM timeout" messages started to appear in the log. Although I was a little worried about data loss, I've decided to ignore the messages. Things started to go wrong again when copying large files in the guest. The copying process frequently freezed for several minutes and timeouts between 15 and 124 seconds were recorded in the log. In some cases, the timeouts were long enough to cause the copy process to fail.

                 

                It seems that the short timeouts are not causing major problems and I've not experienced any data loss due to these timeouts. But the performance of the guest is definitely affected. The longer timeouts ARE HARMFUL because they can cause I/O operations in the guest to fail. In some cases this can lead to data loss.

                 

                I believe that all of the problems above are related to the combination Linux/VMWare Server/software-RAID. But I could not find an acceptable solution and the problems were serious enough to move the customer to a different virtualization platform...

                 

                Kind regards,

                 

                Justin

                • 5. Re: DISK/CDROM timeout harmful?
                  jakeg Novice

                  Hi Justin,

                   

                  Thanks for your feedback. I'm pretty sure these messages are causing the performance to degrade badly for me, but no obvious data loss at all.

                   

                  You mention software RAID... I'm not using this at all. My host machine is a Dell 1310 laptop with an internal 2.5" HDD.

                   

                  What platform did you end up plumping for instead out of interest?

                   

                  Jake

                  • 6. Re: DISK/CDROM timeout harmful?
                    vmjkx Novice

                    Jake,

                     

                    In my case, the problem only occurs on several (different) systems configured with software RAID. I was not able to reproduce the problem on the same systems without software RAID. But it could very well be that some general property of software RAID and not the software RAID itself causes the problem.

                     

                    Although you didn't experience any obvious data loss, I would be a little careful. The longer (harmful) timeouts only occur when there's heavy I/O. Just take some directories with a lot of files (including a few large files > 2GB) on the guest and copy them (using Windows Explorer) to a network share over a gigabit connection. If no gigabit connection is available, copy them to another directory on the same virtual disk. In my case, the copy process pauses frequently (for several minutes) and sometimes fails completely. Now take another look at the log.

                     

                    I ended up with a MS VS solution for this particular customer. This works well, but required the customer to buy an extra Windows Server license for the host that comes with a lot of overhead. So I would be very happy if someone could come up with an explanation/solution for these problems...

                     

                    Kind regards,

                     

                    Justin

                     

                    Message was edited by: vmjkx