CAM Target over FC and UNMAP problem

[Christopher Forgeron]

Did this ever progress further? I'm load testing 10.2 zvol / UNMAP, and
having similar lockup issues.

On Thu, Mar 5, 2015 at 1:10 PM, Emil Muratov <gpm at hotplug.ru> wrote:

>
> I've got an issue with CTL UNMAP and zvol backends.
> Seems that UNMAP from the initiator passed to the underlying disks
> (without trim support) causes IO blocking to the whole pool. Not sure
> where to address this problem.
>
> My setup:
>  - plain SATA 7.2 krpm drives attached to Adaptec aacraid SAS controller
>  - zfs raidz pool over plain drives, no partitioning
>  - zvol created with volmode=dev
>  - Qlogic ISP 2532 FC HBA in target mode
>  - FreeBSD 10.1-STABLE #1 r279593
>
> Create a new LUN with a zvol backend
>
> ctladm realsync off
> ctladm port -o on -p 5
> ctladm create -b block -o file=/dev/zvol/wd/tst1 -o unmap=on -l 0 -d
> wd.tst1 -S tst1
>
> Both target an initiator hosts connected to the FC fabric. Initiator is
> Win2012 server, actually it is a VM with RDM LUN to the guest OS.
> Formating, reading and writing large amounts of data (file copy/IOmeter)
> - so far so good.
> But as soon as I've tried to delete large files all IO to the LUN
> blocks, initiator system just iowaits. gstat on target shows that
> underlying disk load bumped to 100%, queue up to 10, but no iowrites
> actually in progress, only decent amount of ioreads. After a minute or
> so IO unblocks for a second or two than blocks again and so on again
> until all UNMAPs are done, it could take up to 5 minutes to delete 10Gb
> file. I can see that 'logicalused' property of a zvol shows that the
> deleted space was actually released. System log is filled with CTL msgs:
>
>
> kernel: (ctl2:isp1:0:0:3): ctlfestart: aborted command 0x12aaf4 discarded
> kernel: (2:5:3/3): WRITE(10). CDB: 2a 00 2f d4 74 b8 00 00 08 00
> kernel: (2:5:3/3): Tag: 0x12ab24, type 1
> kernel: (2:5:3/3): ctl_process_done: 96 seconds
> kernel: (ctl2:isp1:0:0:3): ctlfestart: aborted command 0x12afa4 discarded
> kernel: (ctl2:isp1:0:0:3): ctlfestart: aborted command 0x12afd4 discarded
> kernel: ctlfedone: got XPT_IMMEDIATE_NOTIFY status 0x36 tag 0xffffffff
> seq 0x121104
> kernel: (ctl2:isp1:0:0:3): ctlfe_done: returning task I/O tag 0xffffffff
> seq 0x1210d4
>
>
> I've tried to tackle some sysctls, but no success so far.
>
> vfs.zfs.vdev.bio_flush_disable: 1
> vfs.zfs.vdev.bio_delete_disable: 1
> vfs.zfs.trim.enabled=0
>
>
> Disabling UNMAP in CTL (-o unmap=off) resolves the issue completely but
> than there is no space reclamation for zvol.
>
> Any hints would be appreciated.
>
>
>
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