On Tue, Oct 18, 2005 at 05:20:37PM +0100, bob flynn wrote: > >From: Ed Wilts <ewilts ewilts org> > >>I have a question regarding configuring qalogic 2340 cardsin > >>failover mode. > >> > >>I have two of the above fibre cards supporting a storagetek > >>diskarray, which is providing non-bootable partitions from a > >>single host. There are no switches in the configuration, the fibre > >>cards are directly connected to the diskarray. > >> > >>My understanding is the default installation of the driver ( from > >>qla2x00-v7.05.00-1.noarch.rpm ) via qlinstall installs the cards > >>in in persistant mode, which precludes failover. > >> > >>So, can anyone confirm this, and if so, what are the correct steps > >>to install and test under a failover configuration. > > > >Arjan confirmed this. Red Hat supported this in RHEL 3 and even though > >Qlogic has failover support in the driver they ship, Red Hat decided to > >pull the functionality in RHEL 4. <insert expletive here>. > > > >You can either not use the driver's failover functionality or you can > >download the driver from qlogic's web site. There are packaged qla2xxx rpms for RHEL4U2 at http://atrpms.net/dist/el4/qla2xxx/. > >Red Hat recommends that you use the dm-multipath stuff instead. This is > >brand new functionality that was just introduced in Update 2. Yes, and it works quite well. People on storageworks will see only a small performance gain for now, but will have failover. > So if running in a RH 3 environment ( which I am at the moment ), my > options are; > > - stick with RH driver or > - install qlogic driver > from what you are saying, this will work and I can shy away from > dm-multipath for the moment. I assume from what you are saying about > being just introduced in U2 that it is not available as a possible > configuration for Taroon ( as provided by Redhat ). > > I was flicking through the archive of this list, and a question is > bugging me. > > With a qlogic driver, can I achive failover *or *load balancing. but not > both at the same time. I guess throughput and availability are wanted, > but if I cannot have both, then I need to make a call. I think the qlogic driver only has failover. What is labeled as "static load ballancing" is placing *different* luns on *different* active paths. E.g. you get load ballancing for simultaneous access across different mount points. This is in contrast to multipath which places the same device across all active paths. So every device access is load-ballanced over all active paths. -- Axel.Thimm at ATrpms.net
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