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author | rpokala <rpokala@FreeBSD.org> | 2016-01-09 05:07:02 +0000 |
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committer | rpokala <rpokala@FreeBSD.org> | 2016-01-09 05:07:02 +0000 |
commit | 8120f17059427acef6857f4445f402c4646a266a (patch) | |
tree | d9c1c3aee9cefe821ac780215f1345ecc511ffca | |
parent | d5fe9e0efae46c54e8bfb0f9b09b0cb13f97bec2 (diff) | |
download | FreeBSD-src-8120f17059427acef6857f4445f402c4646a266a.zip FreeBSD-src-8120f17059427acef6857f4445f402c4646a266a.tar.gz |
MFC r292123: Document mps.enable_ssu
mps(4) sends StartStopUnit to SATA direct-access devices during shutdown.
Document the tunables which control that behavior.
Approved by: jhb
Sponsored by: Panasas, Inc.
-rw-r--r-- | share/man/man4/mps.4 | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/share/man/man4/mps.4 b/share/man/man4/mps.4 index 6840c21..7e910b1 100644 --- a/share/man/man4/mps.4 +++ b/share/man/man4/mps.4 @@ -34,7 +34,7 @@ .\" $Id: //depot/SpectraBSD/head/share/man/man4/mps.4#6 $ .\" $FreeBSD$ .\" -.Dd January 3, 2013 +.Dd December 9, 2015 .Dt MPS 4 .Os .Sh NAME @@ -129,6 +129,8 @@ driver instance, set the following tunable value in dev.mps.X.disable_msix=1 .Ed .Pp +where X is the adapter number. +.Pp To set the maximum number of DMA chains allocated for all adapters, set the following variable in .Xr loader.conf 5 : @@ -166,6 +168,39 @@ The maximum number of active I/O command seen since boot is shown in the dev.mps.X.io_cmds_highwater .Xr sysctl 8 variable. +.Pp +The adapter can issue the +.Sy StartStopUnit +SCSI command to SATA direct-access devices during shutdown, to allow the +device to quiesce before being powered down. +To control this feature for all adapters, set the +.Bd -literal -offset indent +hw.mps.enable_ssu +.Ed +.Pp +tunable value in +.Xr loader.conf 5 +to one of the following values: +.Bl -tag -width 6n -offset indent +.It 0 +Do not send SSU to either HDDs or SSDs. +.It 1 +Send SSU to SSDs, but not to HDDs; this is the default value. +.It 2 +Send SSU to HDDs, but not to SSDs. +.It 3 +Send SSU to both HDDs and SSDs. +.El +.Pp +To control the feature for a specific adapter, set the following tunable +value in +.Xr loader.conf 5 : +.Bd -literal -offset indent +dev.mps.X.enable_ssu +.Ed +.Pp +where X is the adapter number. +The same set of values are valid as for all adapters. .Sh DEBUGGING To enable debugging prints from the .Nm @@ -218,7 +253,7 @@ This man page was written by This driver has a couple of known shortcomings: .Bl -bullet -compact .It -No userland utility available (e.g. +No userland utility available (e.g., .Xr mptutil 8 ) . .It The driver probes devices sequentially. |