https://bugzilla.kernel.org/show_bug.cgi?id=16490 Alain Kalker <a.c.kalker@xxxxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |a.c.kalker@xxxxxxxxx --- Comment #8 from Alain Kalker <a.c.kalker@xxxxxxxxx> --- I submitted a patch to lower the log level to the linux-scsi mailing list. The patch was not accepted; James Bottomley offered this very insightful explanation why the log level should remain high (quoted here for those who are not reading the linux-scsi mailing list): > [...] The condition may be an error. We have > some USB attached storage devices with writeback caches which don't > supply caching information. Treating a writeback device as writethrough > is a potential error because you may lose data as a result of it. > > The error is that we've made an assumption which may damage your data. > > The problem for us is that we can't tell if the assumption is going to > be fatal or not ... the message is harmless for older USB devices. >From doing a little research, I would suggest these steps to mitigate the risk (correct me if I'm wrong or have omitted anything): - Find out if the device has write cache enabled by default, by consulting its documentation, technical specifications, or by contacting the manufacturer. - If the device does have write cache enabled, a quirk parameter can be added to either the kernel commandline or as a module parameter for the usb-storage module[1] - Verify that the device works as expected. [1] For more information on USB storage device quirks and how to configure them, see linux/Documentation/kernel-parameters.txt in the Linux kernel source. -- You are receiving this mail because: You are the assignee for the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
