Page 1 of 1

BLKCACHE_IOERR when creating snapshot

PostPosted: 28. Jan 2011, 10:24
by andbos83
Hi

I am running VirtualBox on a Windows 7 computer, with Solaris 10 as the guest OS. In the beginning everything worked fine, I was able to save the first snapshot. But I can't save a new snapshot, when I try to do it I get the following error:

"The I/O cache encountered an error while updating data in medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY). Make sure there is enough free space on the disk and that the disk is working properly. Operation can be resumed afterwards".

I don't know how even how to troubleshoot this. I didn't change any in the configuration of VirtualBox between the snapshots, just was working in the guest OS. I have enough space both on host OS and guest OS. Disks are working properly.

Thanks in advance.

Kind regards,
Andreas

From the log:

00:06:29.174 I/O cache: Error while writing entry at offset 22065421824 (50688 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.175 VM: Raising runtime error 'BLKCACHE_IOERR' (fFlags=0x6)
00:06:29.175 Changing the VM state from 'RUNNING' to 'SUSPENDING'.
00:06:29.175 I/O cache: Error while writing entry at offset 22065472512 (512 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.191 I/O cache: Error while writing entry at offset 4937101312 (512 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.206 I/O cache: Error while writing entry at offset 22063839744 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.207 I/O cache: Error while writing entry at offset 22065473024 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.208 I/O cache: Error while writing entry at offset 22065735168 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.213 I/O cache: Error while writing entry at offset 22065866240 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.215 I/O cache: Error while writing entry at offset 22065997312 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.216 I/O cache: Error while writing entry at offset 22066128384 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.230 I/O cache: Error while writing entry at offset 22066259456 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.230 I/O cache: Error while writing entry at offset 22066390528 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.231 I/O cache: Error while writing entry at offset 22066521600 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.232 I/O cache: Error while writing entry at offset 22066652672 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.236 I/O cache: Error while writing entry at offset 22066783744 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.238 I/O cache: Error while writing entry at offset 22066914816 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.239 I/O cache: Error while writing entry at offset 22067045888 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.240 I/O cache: Error while writing entry at offset 22065604096 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.241 I/O cache: Error while writing entry at offset 22067176960 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.242 I/O cache: Error while writing entry at offset 22067308032 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.243 I/O cache: Error while writing entry at offset 22067439104 (131072 bytes) to medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY)
00:06:29.284 AIOMgr: Endpoint for file 'C:\Users\andbos\VirtualBox VMs\krakow\Snapshots\{d2f5b74e-8bca-4f31-9296-3e1d93ae5f82}.vmdk' (flags 000c0781) created successfully
00:06:30.253 Changing the VM state from 'SUSPENDING' to 'SUSPENDED'.
00:06:30.257 Console: VM runtime error: fatal=false, errorID=BLKCACHE_IOERR message="The I/O cache encountered an error while updating data in medium "ahci-0-0" (rc=VERR_VD_IMAGE_READ_ONLY). Make sure there is enough free space on the disk and that the disk is working properly. Operation can be resumed afterwards"

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 28. Jan 2011, 15:38
by Perryg
How much free space do you have on your drive?

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 29. Jan 2011, 15:23
by trucbidule
Hello,

Same problem here.
Everything was running OK. Then I stopped the vbox and took a snapshot. During next startup the vbox suspended with the message error (BLKCACHE_IOERR).

OS
Ubuntu 10.10 desktop

Disk space
> 200GB free space on /home

Virtualbox 4.0.2

Permissions on files
RW permissions on vmdk files (including snapshots). These are set by default and are similar to what works for other Vms I use on the same computer.

In the logs
00:03:36.333 I/O cache: Error while writing entry at offset 2148802560 (331776 bytes) to medium "ahci-0-0" (rc=VERR_INVALID_PARAMETER)
00:03:36.333 I/O cache: Error while writing entry at offset 2149236736 (368640 bytes) to medium "ahci-0-0" (rc=VERR_INVALID_PARAMETER)
00:03:36.335 VM: Raising runtime error 'BLKCACHE_IOERR' (fFlags=0x6)
00:03:36.335 Changing the VM state from 'RUNNING' to 'SUSPENDING'.
00:03:36.381 pdmacFileEpInitialize: RTFileOpen /home/user/VirtualBox VMs/machine/Snapshots/{2fe0723c-b23b-4f4c-a58a-6c6f22dac5fe}.vmdk / 000c0781 failed with VERR_INVALID_PARAMETER
00:03:36.381 AIOMgr: Endpoint for file '/home/user/VirtualBox VMs/machine/Snapshots/{2fe0723c-b23b-4f4c-a58a-6c6f22dac5fe}.vmdk' (flags 00000781) created successfully
00:03:36.398 Changing the VM state from 'SUSPENDING' to 'SUSPENDED'.
00:03:36.400 Console: VM runtime error: fatal=false, errorID=BLKCACHE_IOERR message="The I/O cache encountered an error while updating data in medium "ahci-0-0" (rc=VERR_INVALID_PARAMETER). Make sure there is enough free space on the disk and that the disk is working properly. Operation can be resumed afterwards"

Noticeable difference
The main difference between this VM and other VM working great on the same machine is that this one uses .vmdk disks and not .vdi. This has been auto created while importing this VM from a virtual appliance.
The appliance initially was a vbox VM using vdi and some snapshots, working great on the same computer.

The imported appliance did work great too until the snapshot being created.

Could the problem be snapshotting .vmdk files based machines?

Thanks for your suggestions / explanations / ideas!

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 29. Jan 2011, 23:26
by AndrewT
I have a similar problem, again whilst running an appliance that I created myself, after taking a snapshot. There were some problems with this before (viewtopic.php?f=6&t=37753&start=0) which appeared to be fixed by upgrading to v4.0.2

I tried merging the snapshot I had taken and this fixed the problem [the VM is running fine right now], but I have a hunch that it will come back again if I take another snapshot. This really removes one of the advantages of using a VM - I am new to Ubuntu so I want to be able to undo my mistakes!

It appears that this might be a reproducible bug:
* Install VirtualBox on Windows 7 32-bit.
* Create a 32 bit Ubuntu (or other linux) client
* Take some snaphots
* export as Virtual Appliance
* run the Virtual Appliance and take snapshot
* Virtual Appliance fails to run correctly.
I am pretty new to virtual box - I may be doing something wrong so I am reluctant to formally raise this as a bug, but if anyone else can reproduce this then it ought to be raised as a bug.


(Virtual Box v4.0.2 running on Windows 7 32 bit host and Ubuntu 10.10 desktop client)

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 30. Jan 2011, 02:42
by jptech
I'm also having this problem.

- Win7 host
- VBox 4.0.2
- Ubuntu 10.04.1 guest

I did the following before getting the error:

- created a basic guest installation
- exported the guest as an appliance
- imported the appliance
- work on guest
- stop guest
- snapshot 1
- start guest
- work on guest
- stop guest
- snapshot 2
- error starting guest

All of my disks and snapshot files appear to be writable.

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 30. Jan 2011, 03:17
by jptech
Enabling 'Use host I/O cache' for the (AHCI) SATA Controller makes it so my guest will boot up properly.

However, if I go back and disable 'Use host I/O cache' after booting my guest with it enabled, my guest will report errors and reboot continuously until I re-enable 'Use host I/O cache'.

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 30. Jan 2011, 03:22
by Perryg
These kinds of problems that are reproducible should be reported to bugtracker. You will need to setup an account there as it is on a different system. Please don't forget to post your log file there as an attachment and you can also reference this topic.

It would also help if you can post the ticket number here so other can see the progress, add information, or see the final results.

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 30. Jan 2011, 03:47
by jptech
I added a ticket for this:

http://www.virtualbox.org/ticket/8221

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 30. Jan 2011, 03:52
by Perryg
Very well done jptech. Thank you!

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 31. Jan 2011, 15:01
by andbos83
I enabled 'Use host I/O cache' for the (AHCI) SATA Controller and then I could save more snapshots.

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 2. Feb 2011, 22:13
by trucbidule
Hello,

Same here. The workaround "Activating the Use host I/O cache' for the (AHCI) SATA Controller" made the machine work.
Thanks jptech for posting the bug, seems it will be corrected in next maintenance release! So thanks to the dev team and Perryg, too! :)

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 19. Feb 2011, 01:52
by trucbidule
New release installed (4.0.4).
The bug is marked as fixed : (http://www.virtualbox.org/ticket/8221) and in the changelog : # Storage: fixed write errors with snapshots if the host cache is disabled (4.0 regression; bug #8221).

So I tried to undo the workaround "Use host I/O cache' for the (AHCI) SATA Controller". The machine bugs again "BLKCACHE_IOERR".

Is the bug related to the snapshots taken with the previous release or to the VirtualBox engine itself? Ie. should correcting the bug make the existing snapshots work again without using host's cache? If yes, what's going on that makes my VM pause with BLKCACHE_IOERR?
For my understanding, that would be nice if someone could explain what is going wrong with the storage here.

Anyone else still experiencing this bug? Should the ticket be reactivated?

Re: BLKCACHE_IOERR when creating snapshot

PostPosted: 28. Feb 2011, 20:22
by ru323
Same error after creating second snapshot and reboot. Version is 4.0.4.

Second restart of guest system was without errors, so can't reproduce.