virtio_blk (4)
Leading comments
Copyright (c) 2011 Bryan Venteicher All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or o...
NAME
virtio_blk - VirtIO Block driverSYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:device virtio_blk
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf5:
virtio_blk_load="YES"
DESCRIPTION
The ifconfig device driver provides support for VirtIO block devices.LOADER TUNABLES
Tunables can be set at the loader(8) prompt before booting the kernel or stored in loader.conf5.- hw.vtblk.no_ident
- hw.vtblk. X .no_ident
-
These tunables disable retrieving the device identification string from the hypervisor either globally or per-device. The default value is 0.
- hw.vtblk.writecache_mode
- hw.vtblk. X .writecache_mode
-
These tunables determine the write cache mode globally or per-device. The mode can changed only if the ConfigWCE feature is negotiated. Set to 0 for writethrough mode, 1 for writeback mode, and -1 to leave it as-is. The default value is to leave as-is.
SYSCTL VARIABLES
The following variables are available as sysctl(8) variables.- dev.vtblk. X .writecache_mode
-
The write cache mode of the device can be either writethrough (0) or writeback (1). If the ConfigWCE feature is negotiated, the write cache mode can be toggled between writethrough and writeback.