On Thu, 2 Aug 2012 07:07:25 -0600 Corey Kovacs wrte:
> I might be reading this wrong but just in case, I thought I'd point this out.
>
[snip]
> A single node can maintain quorum since 2+3>(9/2).
> In a split brain condition where a single node cannot talk to the other nodes, this could be disastrous.
Thanks for your input, Corey.
As I said before, at this moment I'll have only one node on a site so
I'm also tweaking config to be able to work with one node alone
Anyway I refer to this sentence in manual, also for more than two
nodes configuration (example pertains to a 13 nodes cluster):
"
A cluster must maintain quorum to prevent split-brain issues. If
quorum was not enforced, quorum, a communication error on that same
thirteen-node cluster may cause a situation where six nodes are
operating on the shared storage, while another six nodes are also
operating on it, independently. Because of the communication error,
the two partial-clusters would overwrite areas of the disk and corrupt
the file system. With quorum rules enforced, only one of the partial
clusters can use the shared storage, thus protecting data integrity.
Quorum doesn't prevent split-brain situations, but it does decide who
is dominant and allowed to function in the cluster. Should split-brain
occur, quorum prevents more than one cluster group from doing
anything.
"
This said, in my case my problem is not with quorum, that is gained
when quorum disk becomes master, but with clvmd freezing without
showing any error
As suggested I set up logging for both cluster and lvm.
I also configured lvmetad
The diff between previous lvm.conf and current for further tests is this:
# diff -u lvm.conf lvm.conf.pre020812
--- lvm.conf 2012-08-02 14:48:31.172565731 +0200
+++ lvm.conf.pre020812 2012-08-02 01:33:55.878511113 +0200
@@ -232,8 +232,7 @@
# Controls the messages sent to stdout or stderr.
# There are three levels of verbosity, 3 being the most verbose.
- #verbose = 0
- verbose = 2
+ verbose = 0
# Should we send log messages through syslog?
# 1 is yes; 0 is no.
@@ -242,7 +241,6 @@
# Should we log error and debug messages to a file?
# By default there is no log file.
#file = "/var/log/lvm2.log"
- file = "/var/log/lvm2.log"
# Should we overwrite the log file each time the program is run?
# By default we append.
@@ -251,8 +249,7 @@
# 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
- level = 4
+ level = 0
# Format of output messages
# Whether or not (1 or 0) to indent messages according to their severity
@@ -422,8 +419,7 @@
# Check whether CRC is matching when parsed VG is used multiple times.
# This is useful to catch unexpected internal cached volume group
# structure modification. Please only enable for debugging.
- #detect_internal_vg_cache_corruption = 0
- detect_internal_vg_cache_corruption = 1
+ detect_internal_vg_cache_corruption = 0
# If set to 1, no operations that change on-disk metadata will be
permitted.
# Additionally, read-only commands that encounter metadata in
need of repair
@@ -483,8 +479,7 @@
# libdevmapper. Useful for debugging problems with activation.
# Some of the checks may be expensive, so it's best to use this
# only when there seems to be a problem.
- #checks = 0
- checks = 1
+ checks = 0
# Set to 0 to disable udev synchronisation (if compiled into the binaries).
# Processes will not wait for notification from udev.
cluster.conf changes
# diff cluster.conf cluster.conf.51
2,6c2
< <cluster config_version="52" name="clrhev">
< <dlm log_debug="1" plock_debug="1"/>
< <logging>
< <logging_daemon name="qdiskd" debug="on"/>
< </logging>
---
> <cluster config_version="51" name="clrhev">
In attach I send two files:
lvm2.log with mark separating before and after issue of clvmd start command
clvmd start output.txt that is the output during "service clvmd start" command
to be able to do so, I started in signle user mode and then started
the services one at a time as in
/etc/rc.d/rc3.d/S*
but anticipating the ssh daemon, so that I'm able to login remotely
In fact after clvmd freezes I can only run a pair of sync commands and
power off....
If I'm not missing something stupid I can also post a bugzilla vs
Centos Bug tracker and then eventually someone will report upstream if
reproducible
Gianluca
[root@crhev3 ~]# service clvmd start
Starting clvmd:
Activating VG(s): Logging initialised at Thu Aug 2 15:28:53 2012
Setting global/umask to 63
Set umask from 0022 to 0077
Setting devices/dir to /dev
Setting global/proc to /proc
Setting global/activation to 1
global/suffix not found in config: defaulting to 1
Setting global/units to h
Setting activation/readahead to auto
Setting activation/udev_rules to 1
Setting activation/udev_sync to 1
Setting activation/retry_deactivation to 1
Setting activation/checks to 1
Setting activation/verify_udev_operations to 0
Getting driver version
Setting activation/use_linear_target to 1
Setting activation/missing_stripe_filler to error
Setting global/si_unit_consistency to 1
Setting global/metadata_read_only to 0
Setting devices/pv_min_size to 2048
global/detect_internal_vg_cache_corruption() not found in config: defaulting to 0
Setting global/use_lvmetad to 1
Setting devices/disable_after_error_count to 0
Setting devices/ignore_suspended_devices to 0
Setting devices/cache_dir to /etc/lvm/cache
Setting devices/write_cache_state to 1
Setting activation/reserved_stack to 64
Setting activation/reserved_memory to 8192
Setting activation/process_priority to -18
Initialised format: lvm1
Initialised format: pool
Initialised format: lvm2
global/format not found in config: defaulting to lvm2
Setting response to OK
Setting protocol to lvmetad
Setting version to 1
Initialised segtype: striped
Initialised segtype: zero
Initialised segtype: error
Initialised segtype: free
Setting dmeventd/snapshot_library to libdevmapper-event-lvm2snapshot.so
Initialised segtype: snapshot
Setting dmeventd/mirror_library to libdevmapper-event-lvm2mirror.so
Initialised segtype: mirror
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid1
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid4
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid5
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid5_la
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid5_ra
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid5_ls
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid5_rs
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid6
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid6_zr
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid6_nr
dmeventd/raid_library not found in config: defaulting to libdevmapper-event-lvm2raid.so
Initialised segtype: raid6_nc
Setting dmeventd/thin_library to libdevmapper-event-lvm2thin.so
Initialised segtype: thin-pool
Initialised segtype: thin
Setting backup/retain_days to 30
Setting backup/retain_min to 10
Setting backup/archive_dir to /etc/lvm/archive
Setting backup/backup_dir to /etc/lvm/backup
global/fallback_to_lvm1 not found in config: defaulting to 1
Setting global/locking_type to 3
Setting global/wait_for_locks to 1
Cluster locking selected.
Finding all volume groups
Setting response to OK
Setting response to OK
Setting name to VG_VIRT01
Setting metadata/format to lvm2
Setting id to wFFcfY-NCSG-yKrx-Hz8v-tyzD-nTWK-5EqkFz
Setting format to lvm2
Setting device to 64768
Setting dev_size to 209715200
Setting label_sector to 1
/dev/mapper/mpatha: size is 209715200 sectors
/dev/mapper/mpatha: size is 209715200 sectors
Setting size to 192512
Setting start to 4096
Setting ignore to 0
Setting id to rmEMxt-q8ui-pR8a-NuGa-M15v-DKG9-xKDr45
Setting format to lvm2
Setting device to 64771
Setting dev_size to 314572800
Setting label_sector to 1
/dev/mapper/mpathf: size is 314572800 sectors
/dev/mapper/mpathf: size is 314572800 sectors
Setting size to 1044480
Setting start to 4096
Setting ignore to 0
Setting response to OK
Setting name to VG_VIRT03
Setting metadata/format to lvm2
Setting id to whFL70-Af2W-oN8B-6rCI-w1Hm-XqL0-tuHNR5
Setting format to lvm2
Setting device to 64769
Setting dev_size to 209715200
Setting label_sector to 1
/dev/mapper/mpathc: size is 209715200 sectors
/dev/mapper/mpathc: size is 209715200 sectors
Setting size to 192512
Setting start to 4096
Setting ignore to 0
Setting id to s9Yi3G-6jls-30ds-BzdK-djN8-0yHT-VuSI8R
Setting format to lvm2
Setting device to 64773
Setting dev_size to 104857600
Setting label_sector to 1
/dev/mapper/mpathe: size is 104857600 sectors
/dev/mapper/mpathe: size is 104857600 sectors
Setting size to 1044480
Setting start to 4096
Setting ignore to 0
Setting response to OK
Setting name to VG_VIRT04
Setting metadata/format to lvm2
Setting id to 8crlfj-nuzY-5vaY-QtAb-3SkA-yr9T-EM5Hi2
Setting format to lvm2
Setting device to 64774
Setting dev_size to 209715200
Setting label_sector to 1
/dev/mapper/mpathd: size is 209715200 sectors
/dev/mapper/mpathd: size is 209715200 sectors
Setting size to 1044480
Setting start to 4096
Setting ignore to 0
Setting response to OK
Setting name to VolGroup00
Setting metadata/format to lvm2
Setting id to dStWwU-rc1a-6pmb-3WJG-2qYr-hgDC-SHm0Ve
Setting format to lvm2
Setting device to 26628
Setting dev_size to 100335616
Setting label_sector to 1
/dev/cciss/c0d0p4: size is 100335616 sectors
/dev/cciss/c0d0p4: size is 100335616 sectors
Setting size to 1044480
Setting start to 4096
Setting ignore to 0
Setting response to OK
Setting name to VG_VIRT02
Setting metadata/format to lvm2
Setting id to 9375Nc-Lq2y-qkD1-5PLF-cuIO-Z3uN-YW9asm
Setting format to lvm2
Setting device to 64770
Setting dev_size to 209715200
Setting label_sector to 1
/dev/mapper/mpathb: size is 209715200 sectors
/dev/mapper/mpathb: size is 209715200 sectors
Setting size to 192512
Setting start to 4096
Setting ignore to 0
Finding volume group "VG_VIRT02"
Locking VG V_VG_VIRT02 CR (VG) (0x1)
Setting response to OK
Setting name to VG_VIRT02
Setting metadata/format to lvm2
Setting id to 9375Nc-Lq2y-qkD1-5PLF-cuIO-Z3uN-YW9asm
Setting format to lvm2
Setting device to 64770
Setting dev_size to 209715200
Setting label_sector to 1
/dev/mapper/mpathb: size is 209715200 sectors
/dev/mapper/mpathb: size is 209715200 sectors
Setting size to 192512
Setting start to 4096
Setting ignore to 0
VG_VIRT02/vorastud1 is not active
Locking LV UYtfUWONARtntMxo16uu464Vy7i6eZo7RPMB1JMB1F20VTBEiKlKtP3ZfbRn9xhn CR (LV|NONBLOCK|CLUSTER|LOCAL) (0xd9)
VG_VIRT02/ltsp is not active
Locking LV UYtfUWONARtntMxo16uu464Vy7i6eZo7sW1dCeAZwUfHbpQ55ZZ82Dr2vl7tA009 CR (LV|NONBLOCK|CLUSTER|LOCAL) (0xd9)
VG_VIRT02/droratest_aaadata is not active
Locking LV UYtfUWONARtntMxo16uu464Vy7i6eZo72WNqFXJ2i5UKsiRLqdvdQz2TiR0gG24E CR (LV|NONBLOCK|CLUSTER|LOCAL) (0xd9)
Activated 3 logical volumes in volume group VG_VIRT02
3 logical volume(s) in volume group "VG_VIRT02" now active
Requesting sync names.
Locking VG V_VG_VIRT02 UN (VG) (0x6)
Attachment:
lvm2.log
Description: Binary data
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