Messages in this thread | | | From | Bernd Eckenfels <> | Subject | Re: Accessing the same disk via multiple channels | Date | Thu, 13 Feb 2003 23:45:51 +0100 |
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In article <20030213194917.GA8479@quadpro.stupendous.org> you wrote: > Each server is equipped with 2 FibreChannel cards. The SAN is > configured to present the same disk (which is in fact a virtual > Symmetrix device) over two channels. This means the host sees > two physical devices (as far as that host's concerned) which is > in fact really only one device. In linux terms: /dev/sda and /dev/sdc > are exactly the same disks, but the (standard) OS doesn't know this. ... > How does linux as it is now handle the situation of one physical device > presented via multiple paths (without extra software)?
You can use the multipath option to md which can do that.
Basically there are two options, a failover and a load balancing option. The problem with failover is, to detect the actual failure reliable, toe problem with load balancing is, that not all san configurations allow this.
http://www-124.ibm.com/storageio/multipath/md-multipath/index.php
this is at least in 2.4.20-xfs
Greetings Bernd -- eckes privat - http://www.eckes.org/ Project Freefire - http://www.freefire.org/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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