On 06/06/2012 05:01 PM, Sašo Kiselkov wrote: > I'll try and load the machine with dd(1) to the max to see if access > patterns of my software have something to do with it.
Tried and tested, any and all write I/O to the pool causes this xcall storm issue, writing more data to it only exacerbates it (i.e. it occurs more often). I still get storms of over 100k xcalls completely draining one CPU core, but now they happen in 20-30s intervals rather than every 1-2 minutes. Writing to the rpool, however, does not, so I suspect it has something to do with the MPxIO and how ZFS is pumping data into the twin LSI 9200 controllers. Each is attached to a different CPU I/O bridge (since the system has two Opterons, it has two I/O bridges, each handling roughly half of the PCI-e links). I did this in the hope of improving performance (since the HT links to the I/O bridges will be more evenly loaded). Any idea of this might be the cause of this issue? The whole system diagram is: CPU --(ht)-- IOB --(pcie)-- LSI 9200 --(sas)-, | \ (ht) == JBOD | / CPU --(ht)-- IOB --(pcie)-- LSI 9200 --(sas)-' Cheers, -- Saso _______________________________________________ zfs-discuss mailing list firstname.lastname@example.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss