BLKCACHE_IOERR on Fedora Linux F20 3.13.5-200.fc20.x86_64

[Groovie]

Dear sirs,

after upgrading to 3.13.5-200.fc20.x86_64 i ran into problems with my USP3 mounted SSD drive. This did not happened before, so it should be a problem with the recent kernel update.

[configuration]: Host: Fedora Linux F20 VM: Windows 7 with

• a mapped C: drive vmdk file
• a mounted c:\usp device over usb3 as a map device

Before you ask: why this configuration: The portable ssd device contains my development environment, that i share between home and my office. It worked good before the recent kernel update.

After some time, i'll get a:

Während der Ausführung der virtuellen Maschine ist ein Fehler aufgetreten. Einzelheiten werden unten gezeigt. Sie können versuchen, den angezeigten Fehler zu beheben und mit der Ausführung fortzufahren.

The I/O cache encountered an error while updating data in medium "ahci-0-1" (rc=VERR_DEV_IO_ERROR). Make sure there is enough free space on the disk and that the disk is working properly. Operation can be resumed afterwards.

Fehler ID: BLKCACHE_IOERR Dringlichkeit:Normaler Fehler

There is enough disk space on all devives (approx 16 to 30% usage).

[Groovie]

recent log file

[Groovie]

The problem disappeared, iff i enable the Host-I/O cache for the local drive C and the mounted USP drive.

Besides the responsiveness and the overall perfromance is much better than before.

Is there somebody out there who can tell me, that enabling the host-IO cache does not have harm any other functionality.

Thanks in adance. Groovie

[Frank Mehnert]

Your virtual disk image is located on a btrfs partition, that's most likely the reason for your problems. Make sure that the No_COW flags is set for the virtual disk image files, see ​here.