Olaf Faaland db2af93d72 Increase default zfs_multihost_fail_intervals and import_intervals ... By default, when multihost is enabled for a pool, the pool is suspended if (zfs_multihost_fail_intervals*zfs_multihost_interval) ms pass without a successful MMP write. This is the recommended configuration. The default value for zfs_multihost_fail_intervals has been 5, and the default value for zfs_multihost_interval has been 1000, so pool suspension occurred at 5 seconds. There have been multiple cases where a single misbehaving device in a pool triggered a SCSI reset, and all I/O paused for 5-6 seconds. This in turn caused MMP to suspend the pool. In the cases observed, the rest of the devices were healthy and the pool was otherwise correctly performing I/O. The reset was handled correctly by ZFS, and by suspending the pool MMP made replacing the device more difficult as well as forcing the host to be rebooted. Increase the default value of zfs_multihost_fail_intervals to 10, so that MMP tolerates up to 10 seconds of failed MMP writes before suspending the pool. Increase the default value of zfs_multihost_import_intervals to 20, to maintain the 2:1 safety factor. This results in a force import taking approximately 20 seconds when MMP is enabled, with default values. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com> Reviewed-by: George Melikov <mail@gmelikov.ru> Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Closes #7709 Closes #8495		2019-03-13 09:50:48 -07:00
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man1	Update build system and packaging	2018-05-29 16:00:33 -07:00
man5	Increase default zfs_multihost_fail_intervals and import_intervals	2019-03-13 09:50:48 -07:00
man8	Do not resume a pool if multihost is enabled	2019-02-28 17:56:19 -08:00
Makefile.am	Prepare SPL repo to merge with ZFS repo	2018-05-29 14:51:39 -07:00