camcontrol rescan not updating disk size?

[John-Mark Gurney]

Douglas Gilbert wrote this message on Mon, Dec 16, 2013 at 12:27 -0500:
> On 13-12-16 11:44 AM, Rolf Grossmann wrote:
> >Hi,
> >
> >I'm having a problem with a virtualized system. I've grown the virtual
> >disk, but my FreeBSD 9.1-STABLE r246991 won't recognize the new size:
> >
> ># grep da1 /var/run/dmesg.boot
> >da1 at mpt0 bus 0 scbus2 target 1 lun 0
> >da1: <VMware Virtual disk 1.0> Fixed Direct Access SCSI-2 device
> >da1: 320.000MB/s transfers (160.000MHz DT, offset 127, 16bit)
> >da1: Command Queueing enabled
> >da1: 75776MB (155189248 512 byte sectors: 255H 63S/T 9660C)
> >
> ># camcontrol readcap 2:1:0
> >Last Block: 314572799, Block Length: 512 bytes
> >
> ># camcontrol rescan 2:1:0
> >Re-scan of 2:1:0 was successful
> >
> ># geom disk list da1
> >Geom name: da1
> >Providers:
> >1. Name: da1
> >    Mediasize: 79456894976 (74G)
> >    Sectorsize: 512
> >    Mode: r1w1e1
> >    descr: VMware Virtual disk
> >    ident: (null)
> >    fwsectors: 63
> >    fwheads: 255
> >
> >IMHO that should now read "Mediasize: 161061273088 (150G)".
> >
> >(What I'm actually trying to do is "zpool online -e mypool da1", but
> >that doesn't recognize the new size either, so I'm thinking geom is a
> >good indicator of the system's idea of the disk size.)
> >
> >I've tried a full and targetd rescan multiple times to no avail. I don't
> >see anything to rescan the size or flush some sort of cache. My Google
> >searches also came up empty. I'm out of ideas what else to try short of
> >a reboot (which I'd really like to avoid).
> 
> A related point: according to sbc3r36.pdf when an LU changes its
> size then it should "establish a unit attention condition with an
> additional sense code set to CAPACITY DATA HAS CHANGED". Can you
> determine if that happens? If it does then CAM needs enhancing, if
> not targetd needs some work.

Just a quick search of the CAM code, and it looks like -HEAD does handle
the CAPACITY DATA HAS CHANGED message.. sys/scsi/scsi_da.c:3537...

A reboot would definately fix it, though it sounds like you're trying
to avoid that...

It also looks like a reopen of the device would reprobe the size...

You could try to zpool replace w/ it self, but that might not cause
a reopen, or if it's part of a mirror/raidz volume, you could
offline/online the device and then it should have the new sizes... In
my experience, zfs will detect the device already has valid data on
it, and not have to resilver the whole device, but as usual, make sure
you have good backups.. :)

A zpool export/import would obviously do the same thing...

Hope this helps.

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."