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author | jimharris <jimharris@FreeBSD.org> | 2016-02-17 15:38:05 +0000 |
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committer | jimharris <jimharris@FreeBSD.org> | 2016-02-17 15:38:05 +0000 |
commit | efd4fe5452c6487edb2d6291278f022cd05d2296 (patch) | |
tree | bb952af01dd1d0ea1bf66f34324d086588f26a6e /share | |
parent | b9d4be0c4e918d40c0526998dc097fccb3d08426 (diff) | |
download | FreeBSD-src-efd4fe5452c6487edb2d6291278f022cd05d2296.zip FreeBSD-src-efd4fe5452c6487edb2d6291278f022cd05d2296.tar.gz |
MFC r295022:
nvd: add hw.nvd.delete_max tunable
The NVMe specification does not define a maximum or optimal delete
size, so technically max delete size is min(full size of namespace,
2^32 - 1 LBAs). A single delete operation for a multi-TB NVMe
namespace though may take much longer to complete than the nvme(4)
I/O timeout period. So choose a sensible default here that is still
suitably large to minimize the number of overall delete operations.
This also fixes possible uint32_t overflow on initial TRIM operation
for zpool create operations for NVMe namespaces with >4G LBAs.
Approved by: re (glebius)
Sponsored by: Intel
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man4/nvd.4 | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/share/man/man4/nvd.4 b/share/man/man4/nvd.4 index 15200a4..4018dd8 100644 --- a/share/man/man4/nvd.4 +++ b/share/man/man4/nvd.4 @@ -1,5 +1,5 @@ .\" -.\" Copyright (c) 2012-2014 Intel Corporation +.\" Copyright (c) 2012-2016 Intel Corporation .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without @@ -33,7 +33,7 @@ .\" .\" $FreeBSD$ .\" -.Dd March 18, 2014 +.Dd January 28, 2016 .Dt NVD 4 .Os .Sh NAME @@ -74,6 +74,15 @@ Note that device nodes from the driver are not .Xr GEOM 4 disks and cannot be partitioned. +.Sh CONFIGURATION +The +.Nm +driver defines a system-wide maximum delete size for NVMe devices. The +default is 1GB. To select a different value, set the following tunable in +.Xr loader.conf 5 : +.Bd -literal -offset indent +hw.nvd.delete_max=<delete size in bytes> +.Ed .Sh SEE ALSO .Xr GEOM 4 , .Xr nvme 4 , |