[dm-devel] Multipathing with RHEL4 U2 on EMC DMX
Brian Long
brilong at cisco.com
Wed Feb 15 19:52:12 UTC 2006
On Fri, 2006-02-10 at 08:48 -0600, Child, David wrote:
> Hello,
>
> I've just recently connected some HP BL20p G3 blades running RHEL4 U2
> up to a DMX2000 (via McData switches). We didn't get PowerPath and
> intended to use device-mapper multipathing. I was able to get things
> up for the most part and get devices defined, but have to do that
> manually.
Hello David,
We have a /etc/lvm/lvm.conf and /etc/multipath.conf tweak you may be
interested in. I've attached them to this email.
/Brian/
--
Brian Long | | |
IT Data Center Systems | .|||. .|||.
Cisco Linux Developer | ..:|||||||:...:|||||||:..
Phone: (919) 392-7363 | C i s c o S y s t e m s
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# Refer to 'man lvm.conf' for further information including the file layout.
#
# To put this file in a different directory and override /etc/lvm set
# the environment variable LVM_SYSTEM_DIR before running the tools.
# This section allows you to configure which block devices should
# be used by the LVM system.
devices {
# Where do you want your volume groups to appear ?
dir = "/dev"
# An array of directories that contain the device nodes you wish
# to use with LVM2.
scan = [ "/dev" ]
# A filter that tells LVM2 to only use a restricted set of devices.
# The filter consists of an array of regular expressions. These
# expressions can be delimited by a character of your choice, and
# prefixed with either an 'a' (for accept) or 'r' (for reject).
# The first expression found to match a device name determines if
# the device will be accepted or rejected (ignored). Devices that
# don't match any patterns are accepted.
# Be careful if there there are symbolic links or multiple filesystem
# entries for the same device as each name is checked separately against
# the list of patterns. The effect is that if any name matches any 'a'
# pattern, the device is accepted; otherwise if any name matches any 'r'
# pattern it is rejected; otherwise it is accepted.
# Remember to run vgscan after you change this parameter to ensure
# that the cache file gets regenerated (see below).
# By default we accept every block device:
# filter = [ "a/.*/" ]
# Cisco filter
filter = [ "a|^/dev/mapper/.*|", "r/.*/" ]
# Exclude the cdrom drive
# filter = [ "r|/dev/cdrom|" ]
# When testing I like to work with just loopback devices:
#filter = [ "a|loop|", "r/.*/" ]
# Or maybe all loops and ide drives except hdc:
# filter =[ "a|loop|", "r|/dev/hdc|", "a|/dev/ide|", "r|.*|" ]
# Use anchors if you want to be really specific
# filter = [ "a|^/dev/hda8$|", "r/.*/" ]
# The results of the filtering are cached on disk to avoid
# rescanning dud devices (which can take a very long time). By
# default this cache file is hidden in the /etc/lvm directory.
# It is safe to delete this file: the tools regenerate it.
cache = "/etc/lvm/.cache"
# You can turn off writing this cache file by setting this to 0.
write_cache_state = 1
# Advanced settings.
# List of pairs of additional acceptable block device types found
# in /proc/devices with maximum (non-zero) number of partitions.
# types = [ "fd", 16 ]
# Cisco added
types = [ "device-mapper", 1 ]
# If sysfs is mounted (2.6 kernels) restrict device scanning to
# the block devices it believes are valid.
# 1 enables; 0 disables.
sysfs_scan = 1
# By default, LVM2 will ignore devices used as components of
# software RAID (md) devices by looking for md superblocks.
# 1 enables; 0 disables.
# Cisco changed
md_component_detection = 0
}
# This section that allows you to configure the nature of the
# information that LVM2 reports.
log {
# Controls the messages sent to stdout or stderr.
# There are three levels of verbosity, 3 being the most verbose.
verbose = 0
# Should we send log messages through syslog?
# 1 is yes; 0 is no.
syslog = 1
# Should we log error and debug messages to a file?
# By default there is no log file.
#file = "/var/log/lvm2.log"
# Should we overwrite the log file each time the program is run?
# By default we append.
overwrite = 0
# What level of log messages should we send to the log file and/or syslog?
# There are 6 syslog-like log levels currently in use - 2 to 7 inclusive.
# 7 is the most verbose (LOG_DEBUG).
level = 0
# Format of output messages
# Whether or not (1 or 0) to indent messages according to their severity
indent = 1
# Whether or not (1 or 0) to display the command name on each line output
command_names = 0
# A prefix to use before the message text (but after the command name,
# if selected). Default is two spaces, so you can see/grep the severity
# of each message.
prefix = " "
# To make the messages look similar to the original LVM tools use:
# indent = 0
# command_names = 1
# prefix = " -- "
# Set this if you want log messages during activation.
# Don't use this in low memory situations (can deadlock).
# activation = 0
}
# Configuration of metadata backups and archiving. In LVM2 when we
# talk about a 'backup' we mean making a copy of the metadata for the
# *current* system. The 'archive' contains old metadata configurations.
# Backups are stored in a human readeable text format.
backup {
# Should we maintain a backup of the current metadata configuration ?
# Use 1 for Yes; 0 for No.
# Think very hard before turning this off!
backup = 1
# Where shall we keep it ?
# Remember to back up this directory regularly!
backup_dir = "/etc/lvm/backup"
# Should we maintain an archive of old metadata configurations.
# Use 1 for Yes; 0 for No.
# On by default. Think very hard before turning this off.
archive = 1
# Where should archived files go ?
# Remember to back up this directory regularly!
archive_dir = "/etc/lvm/archive"
# What is the minimum number of archive files you wish to keep ?
retain_min = 10
# What is the minimum time you wish to keep an archive file for ?
retain_days = 30
}
# Settings for the running LVM2 in shell (readline) mode.
shell {
# Number of lines of history to store in ~/.lvm_history
history_size = 100
}
# Miscellaneous global LVM2 settings
global {
# The file creation mask for any files and directories created.
# Interpreted as octal if the first digit is zero.
umask = 077
# Allow other users to read the files
#umask = 022
# Enabling test mode means that no changes to the on disk metadata
# will be made. Equivalent to having the -t option on every
# command. Defaults to off.
test = 0
# Whether or not to communicate with the kernel device-mapper.
# Set to 0 if you want to use the tools to manipulate LVM metadata
# without activating any logical volumes.
# If the device-mapper kernel driver is not present in your kernel
# setting this to 0 should suppress the error messages.
activation = 1
# If we can't communicate with device-mapper, should we try running
# the LVM1 tools?
# This option only applies to 2.4 kernels and is provided to help you
# switch between device-mapper kernels and LVM1 kernels.
# The LVM1 tools need to be installed with .lvm1 suffices
# e.g. vgscan.lvm1 and they will stop working after you start using
# the new lvm2 on-disk metadata format.
# The default value is set when the tools are built.
# fallback_to_lvm1 = 0
# The default metadata format that commands should use - "lvm1" or "lvm2".
# The command line override is -M1 or -M2.
# Defaults to "lvm1" if compiled in, else "lvm2".
# format = "lvm1"
# Location of proc filesystem
proc = "/proc"
# Type of locking to use. Defaults to file-based locking (1).
# Turn locking off by setting to 0 (dangerous: risks metadata corruption
# if LVM2 commands get run concurrently).
locking_type = 1
# Local non-LV directory that holds file-based locks while commands are
# in progress. A directory like /tmp that may get wiped on reboot is OK.
locking_dir = "/var/lock/lvm"
# Other entries can go here to allow you to load shared libraries
# e.g. if support for LVM1 metadata was compiled as a shared library use
# format_libraries = "liblvm2format1.so"
# Full pathnames can be given.
# Search this directory first for shared libraries.
# library_dir = "/lib"
}
activation {
# Device used in place of missing stripes if activating incomplete volume.
# For now, you need to set this up yourself first (e.g. with 'dmsetup')
# For example, you could make it return I/O errors using the 'error'
# target or make it return zeros.
missing_stripe_filler = "/dev/ioerror"
# Size (in KB) of each copy operation when mirroring
mirror_region_size = 512
# How much stack (in KB) to reserve for use while devices suspended
reserved_stack = 256
# How much memory (in KB) to reserve for use while devices suspended
reserved_memory = 8192
# Nice value used while devices suspended
process_priority = -18
# If volume_list is defined, each LV is only activated if there is a
# match against the list.
# "vgname" and "vgname/lvname" are matched exactly.
# "@tag" matches any tag set in the LV or VG.
# "@*" matches if any tag defined on the host is also set in the LV or VG
#
# volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]
}
####################
# Advanced section #
####################
# Metadata settings
#
# metadata {
# Default number of copies of metadata to hold on each PV. 0, 1 or 2.
# You might want to override it from the command line with 0
# when running pvcreate on new PVs which are to be added to large VGs.
# pvmetadatacopies = 1
# Approximate default size of on-disk metadata areas in sectors.
# You should increase this if you have large volume groups or
# you want to retain a large on-disk history of your metadata changes.
# pvmetadatasize = 255
# List of directories holding live copies of text format metadata.
# These directories must not be on logical volumes!
# It's possible to use LVM2 with a couple of directories here,
# preferably on different (non-LV) filesystems, and with no other
# on-disk metadata (pvmetadatacopies = 0). Or this can be in
# addition to on-disk metadata areas.
# The feature was originally added to simplify testing and is not
# supported under low memory situations - the machine could lock up.
#
# Never edit any files in these directories by hand unless you
# you are absolutely sure you know what you are doing! Use
# the supplied toolset to make changes (e.g. vgcfgrestore).
# dirs = [ "/etc/lvm/metadata", "/mnt/disk2/lvm/metadata2" ]
#}
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# See /usr/share/doc/device-mapper-multipath-*/multipath.conf.annotated
# for a fully-detailed multipath.conf.
#
# BEGIN Cisco-specific configuration
defaults {
multipath_tool "/sbin/multipath -v0"
udev_dir /dev
polling_interval 10
default_selector "round-robin 0"
default_path_grouping_policy multibus
default_getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
default_prio_callout "/bin/true"
default_features "0"
rr_wmin_io 100
failback immediate
}
# Only specify options in the devices section to override the defaults.
devices {
# EMC Symmetrix / DMX
device {
vendor "EMC "
product "SYMMETRIX "
}
# EMC Clariion (active/passive)
device {
vendor "DGC "
product "RAID 5 "
path_grouping_policy failover
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
path_checker emc_clariion
path_selector "round-robin 0"
features "0"
hardware_handler "1 emc"
failback immediate
}
device {
vendor "DGC "
product " "
path_grouping_policy failover
getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
path_checker emc_clariion
path_selector "round-robin 0"
features "0"
hardware_handler "1 emc"
failback immediate
}
}
# END Cisco-specific configuration
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