OpenZFS on Linux and FreeBSD
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Brian Behlendorf 97d19a5e45 Add linux-events topic branch for zevent handling.
This topic branch leverages the Solaris style FMA call points
in ZFS to create a user space visible event notification system
under Linux.  This new system is called zevent and it unifies
all previous Solaris style ereports and sysevent notifications.

Under this Linux specific scheme when a sysevent or ereport event
occurs an nvlist describing the event is created which looks almost
exactly like a Solaris ereport.  These events are queued up in the
kernel when they occur and conditionally logged to the console.
It is then up to a user space application to consume the events
and do whatever it likes with them.

To make this possible the existing /dev/zfs ABI has been extended
with two new ioctls which behave as follows.

* ZFS_IOC_EVENTS_NEXT
Get the next pending event.  The kernel will keep track of the last
event consumed by the file descriptor and provide the next one if
available.  If no new events are available the ioctl() will block
waiting for the next event.  This ioctl may also be called in a
non-blocking mode by setting zc.zc_guid = ZEVENT_NONBLOCK.  In the
non-blocking case if no events are available ENOENT will be returned.
It is possible that ESHUTDOWN will be returned if the ioctl() is
called while module unloading is in progress.  And finally ENOMEM
may occur if the provided nvlist buffer is not large enough to
contain the entire event.

* ZFS_IOC_EVENTS_CLEAR
Clear are events queued by the kernel.  The kernel will keep a fairly
large number of recent events queued, use this ioctl to clear the
in kernel list.  This will effect all user space processes consuming
events.

The zpool command has been extended to use this events ABI with the
'events' subcommand.  You may run 'zpool events -v' to output a
verbose log of all recent events.  This is very similar to the
Solaris 'fmdump -ev' command with the key difference being it also
includes what would be considered sysevents under Solaris.  You
may also run in follow mode with the '-f' option.  To clear the
in kernel event queue use the '-c' option.

$ sudo cmd/zpool/zpool events -fv
TIME                        CLASS
May 13 2010 16:31:15.777711000 ereport.fs.zfs.config.sync
        class = "ereport.fs.zfs.config.sync"
        ena = 0x40982b7897700001
        detector = (embedded nvlist)
                version = 0x0
                scheme = "zfs"
                pool = 0xed976600de75dfa6
        (end detector)

        time = 0x4bec8bc3 0x2e5aed98
        pool = "zpios"
        pool_guid = 0xed976600de75dfa6
        pool_context = 0x0

While the 'zpool events' command is handy for interactive debugging
it is not expected to be the primary consumer of zevents.  This ABI
was primarily added to facilitate the addition of a user space
monitoring daemon.  This daemon would consume all events posted by
the kernel and based on the type of event perform an action.  For
most events simply forwarding them on to syslog is likely enough.
But this interface also cleanly allows for more sophisticated
actions to be taken such as generating an email for a failed drive
2010-05-14 12:40:44 -07:00
cmd Add linux-events topic branch for zevent handling. 2010-05-14 12:40:44 -07:00
config Add top level SPL include path which is needed for *-devel builds 2010-04-22 09:55:07 -07:00
etc Remove promise example config replace with a supermicro config 2010-03-11 14:04:12 -08:00
lib Add linux-events topic branch for zevent handling. 2010-05-14 12:40:44 -07:00
man Add man pages to the build system and packages. 2009-12-11 16:49:25 -08:00
module Add linux-events topic branch for zevent handling. 2010-05-14 12:40:44 -07:00
patches Add e2fsprogs patch for detecting ZFS uberblocks until it appears upstream. 2009-11-02 15:04:43 -08:00
scripts Merge commit 'refs/top-bases/zfs-branch' into zfs-branch 2010-04-29 12:04:36 -07:00
.gitignore Ignore unsigned module build products 2010-03-09 14:14:09 -08:00
.topdeps Add linux-events topic branch for zevent handling. 2010-05-14 12:40:44 -07:00
.topmsg Add linux-events topic branch for zevent handling. 2010-05-14 12:40:44 -07:00
AUTHORS Refresh zfs-branch 2008-12-05 09:46:11 -08:00
COPYING Refresh for consistency with COPYRIGHT 2009-06-08 11:59:13 -07:00
COPYRIGHT Readd accidentally dropped COPYRIGHT, it just references the 2009-06-08 11:01:13 -07:00
ChangeLog Prep for 0.4.8 tag, updated META and ChangeLog 2010-03-11 16:25:03 -08:00
DISCLAIMER Initial Linux ZFS GIT Repo 2008-11-20 12:01:55 -08:00
GIT Refresh type in topgit git://* reference 2009-01-26 21:58:32 -08:00
META Prep for 0.4.8 tag, updated META and ChangeLog 2010-03-11 16:25:03 -08:00
Makefile.am Allow zfs_config.h to be included by dependant packages (updated) 2010-03-22 16:42:18 -07:00
OPENSOLARIS.LICENSE Add CDDL license file 2008-12-01 14:49:34 -08:00
README Refresh README 2009-01-20 16:16:57 -08:00
TODO Prep for 0.4.6 tag, updated META, ChangeLog, and TODO. 2009-11-02 13:03:59 -08:00
ZFS.RELEASE Rebase master to b121 2009-08-18 11:43:27 -07:00
autogen.sh Core target arch support for conditional compilation of SUBDIRs 2009-06-08 16:07:43 -07:00
configure.ac Add support for 'make -s' silent builds 2010-03-26 15:41:41 -07:00
zfs-modules.spec.in Fix definitions for the unknown distro/installation 2010-03-08 16:20:20 -08:00
zfs.spec.in Split the udev rule from a specific configuration 2010-03-01 16:51:21 -08:00

README

============================ ZFS KERNEL BUILD ============================

1) Build the SPL (Solaris Porting Layer) module which is designed to
   provide many Solaris APIs in the Linux kernel which are needed
   by ZFS.  To build the SPL:

        tar -xzf spl-x.y.z.tgz
        cd spl-x.y.z
        ./configure --with-linux=<kernel src>
        make
        make check <as root>

2) Build ZFS, this port is based on build specified by the ZFS.RELEASE
   file.  You will need to have both the kernel and SPL source available.
   To build ZFS for use as a Linux kernel module.

        tar -xzf zfs-x.y.z.tgz
        cd zfs-x.y.z
        ./configure --with-linux=<kernel src> \
                    --with-spl=<spl src>
        make
        make check <as root>

============================ ZPIOS TEST SUITE ============================

3) Provided is an in-kernel test application called zpios which can be
   used to simulate a parallel IO load.  It may be used as a stress 
   or performance test for your configuration.  To simplify testing
   scripts provided in the scripts/ directory which provide a few
   pre-built zpool configurations and zpios test cases.  By default
   'make check' as root will run a simple test against several small
   loopback devices created in /tmp/.

       cd scripts
       ./zfs.sh					# Load the ZFS/SPL modules
       ./zpios.sh -c lo-raid0.sh -t tiny -v 	# Tiny zpios loopback test
       ./zfs.sh -u				# Unload the ZFS/SPL modules

Enjoy,
Brian Behlendorf <behlendorf1@llnl.gov>