Date: Tue, 01 Dec 2015 19:34:12 +0200 From: Alexander Motin <mav@FreeBSD.org> To: Christopher Forgeron <csforgeron@gmail.com>, Emil Muratov <gpm@hotplug.ru> Cc: FreeBSD Filesystems <freebsd-fs@freebsd.org> Subject: Re: CAM Target over FC and UNMAP problem Message-ID: <565DDA14.4010006@FreeBSD.org> In-Reply-To: <CAB2_NwDF-TkriMHO5wB7qhf8wY7SVhVzEg-v4k7HM=NS8z8sXg@mail.gmail.com> References: <54F88DEA.2070301@hotplug.ru> <CAB2_NwDF-TkriMHO5wB7qhf8wY7SVhVzEg-v4k7HM=NS8z8sXg@mail.gmail.com>
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Not really. But just as an idea you may try to set tloader unable vfs.zfs.trim.enabled=0 . Aside of obvious disabling TRIM, that is no-op for non-SSD ZFS pool, it also changes the day deletes are handled, possibly making them less blocking. I see no issue here from CTL side -- it does well. It indeed does not limit size of single UNMAP operation, that is not good, but that is because it has no idea about performance of backing store. On 01.12.2015 16:39, Christopher Forgeron wrote: > 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@hotplug.ru > <mailto:gpm@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. > > > > _______________________________________________ > freebsd-fs@freebsd.org <mailto:freebsd-fs@freebsd.org> mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org > <mailto:freebsd-fs-unsubscribe@freebsd.org>" > > -- Alexander Motin
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