On Jun 26 James Bottomley wrote: > On Fri, 2015-06-26 at 11:43 +0200, Stefan Richter wrote: > > On Jun 22 James Bottomley wrote: [...] > > > Perhaps it might be wise to do this to every USB device ... for external > > > devices, the small performance gain doesn't really make up for the > > > potential data loss. > > > > Just a small note on the assumption of externally (and in extension, > > temporarily) attached devices: Not all USB-attached devices are external, > > and not all external devices are used as removable devices. > > The problems don't depend on the connection type: internal devices which > have a writeback cache and don't accept flush commands have data > integrity problems too. I can't really think of many situations where > you'd be willing to sacrifice data integrity for performance.
Sure; writeback caches are prone to more issues besides sudden connection loss. (E.g. sudden power loss is but one of several more potential issues of course.) I merely wanted to remind that the bus type of a device (USB or whatever) does not say much about the risk of sudden connection loss to that device, since such devices may have physical protection against sudden connection loss too. I was not particularly commenting on the topic at hand, i.e. on presence of writeback cache without working flush command. -- Stefan Richter -=====-===== -==- ==-=- http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
