Add knob to disable slow io notifications #17477
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Introduce a new vdev property `VDEV_PROP_SLOW_IO_REPORTING` that allows users to disable notifications for slow devices. This prevents ZED and/or ZFSD from degrading the pool due to slow I/O. Signed-off-by: Mariusz Zaborski <[email protected]>
amotin
reviewed
Jun 24, 2025
| @@ -45,7 +45,7 @@ section, below. | |||
| Every vdev has a set of properties that export statistics about the vdev | |||
| as well as control various behaviors. | |||
| Properties are not inherited from top-level vdevs, with the exception of | |||
| checksum_n, checksum_t, io_n, io_t, slow_io_n, and slow_io_t. | |||
| checksum_n, checksum_t, io_n, io_t, slow_io_downgrade, slow_io_n, and slow_io_t. | |||
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Should here and below be slow_io_reporting instead of slow_io_downgrade?
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slow_io_reporting doesn't seem quite right since we're still counting slow I/Os and reporting them in zpool status -s. Maybe slow_io_events? Although, I don't love that either.
| uint64_t ivalue; | ||
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| err = vdev_prop_get_int(vd, prop, &ivalue); | ||
| *bvalue = ivalue & 1; |
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I wonder if this feature partially duplicates |
allanjude
reviewed
Jun 30, 2025
| @@ -45,7 +45,7 @@ section, below. | |||
| Every vdev has a set of properties that export statistics about the vdev | |||
| as well as control various behaviors. | |||
| Properties are not inherited from top-level vdevs, with the exception of | |||
| checksum_n, checksum_t, io_n, io_t, slow_io_n, and slow_io_t. | |||
| checksum_n, checksum_t, io_n, io_t, slow_io_downgrade, slow_io_n, and slow_io_t. | |||
| } else if (vd->vdev_leaf_zap != 0) { | ||
| objid = vd->vdev_leaf_zap; | ||
| } else { | ||
| if (vdev_prop_get_objid(vd, &objid) != 0) | ||
| panic("unexpected vdev type"); |
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Would it make sense to move the panic() into vdev_prop_get_objid() to save having to test it everywhere it is used?
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Motivation and Context
Adding a knob allows disabling the slow_io check on a single vdev. Some users have reported that it breaks their enterprise configuration when one or more vdevs are using fiber channels with redundancy. Another reason to disable the check might be when a vdev is damaged, but we still want to force some resilvering from it.
Description
Add a knob to disable slow I/O event generation for a single vdev.
How Has This Been Tested?
New test has been added.
Types of changes
Checklist:
Signed-off-by.