On 2005-04-21T23:33:57, Andreas Herrmann <aherrman@xxxxxxxxxx> wrote: > Well, there are various situations when all paths to the ESS are > "temporarily unavailable". In some cases TASK_SET_FULL/BUSY is > reported as it should be. Not sure whether this sense data is decoded and handled correctly in dm-mpath yet. I don't have detailed specs, nor a feature request to allocate time to work on making sure it really does. I recommend that someone at IBM takes the real specs for the ESS and makes sure that it all works, by a combination of the right defaults in the multipath-tools hwtable and, if need be, a dm-ess plugin to handle this. This would be much appreciated. > underruns or exchange sequences are aborted and finally it might be > that requests just time out. BTW, it is not only ESS where I have seen > such (broken) behaviour. Well, what can I say. Broken behaviour needs to be documented and worked around, but obviously only as far as that is possible. > > It is possible that to fully support them a dm mpath hardware handler > > (like for the EMC CX family) might be required, too. > For the time being I hope "queue_if_no_path" feature is sufficient > to succesfully pass our tests ;-) If it is sufficient, you might at least wish to update the multipath-tools hwtable entry so that it is automagically set for your arrays. Sincerely, Lars Marowsky-Brée <lmb@xxxxxxx> -- High Availability & Clustering SUSE Labs, Research and Development SUSE LINUX Products GmbH - A Novell Business