Messages in this thread | | | Date | Thu, 6 Nov 2014 11:16:53 -0600 | From | Chris Friesen <> | Subject | Re: absurdly high "optimal_io_size" on Seagate SAS disk |
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On 11/06/2014 10:47 AM, Chris Friesen wrote: > Hi, > > I'm running a modified 3.4-stable on relatively recent X86 server-class > hardware. > > I recently installed a Seagate ST900MM0026 (900GB 2.5in 10K SAS drive) > and it's reporting a value of 4294966784 for optimal_io_size. The other > parameters look normal though: > > /sys/block/sda/queue/hw_sector_size:512 > /sys/block/sda/queue/logical_block_size:512 > /sys/block/sda/queue/max_segment_size:65536 > /sys/block/sda/queue/minimum_io_size:512 > /sys/block/sda/queue/optimal_io_size:4294966784
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> According to the manual, the ST900MM0026 has a 512 byte physical sector > size. > > Is this a drive firmware bug? Or a bug in the SAS driver? Or is there > a valid reason for a single drive to report such a huge value? > > Would it make sense for the kernel to do some sort of sanity checking on > this value?
Looks like this sort of thing has been seen before, in other drives (one of which is from the same family as my drive):
http://www.spinics.net/lists/linux-scsi/msg65292.html
http://iamlinux.technoyard.in/blog/why-is-my-ssd-disk-not-reconized-by-the-rhel6-anaconda-installer/
Perhaps the ST900MM0026 should be blacklisted as well?
Or maybe the SCSI code should do a variation on Mike Snitzer's original patch and just ignore any values above some reasonable threshold? (And then we could remove the blacklist on the ST900MM0006.)
Chris
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