kexec May 2015

kexec@lists.fedoraproject.org

6 participants
14 discussions

[PATCH RFC] module-setup.sh: install usb serial driver for ttyUSB0
by Dave Young 27 May '16

27 May '16

In case one want to use usb serial console, we need to pack the usb serial driver into kdump initramfs so that one can see the console output on the usb console. I only handled ttyUSB0, this is like a hard code, but it should be enough for most cases. Also only install the driver for the ttyUSB0 device. Tested with adding "console=ttyUSB0" in 2nd kernel commandline. Tested latest F22 kernel, there's CONFIG_USB_SERIAL_CONSOLE=y, kdump work ok. Signed-off-by: Dave Young <dyoung(a)redhat.com> --- dracut-module-setup.sh | 8 ++++++++ 1 file changed, 8 insertions(+) --- kexec-tools.orig/dracut-module-setup.sh +++ kexec-tools/dracut-module-setup.sh @@ -626,4 +626,12 @@ installkernel() { [ "$wdt" = "iTCO_wdt" ] && instmods lpc_ich instmods $wdt fi + + if [ -c /dev/ttyUSB0 ]; then + _majmin=$(get_maj_min /dev/ttyUSB0) + + _driver=$(readlink /sys/dev/char/$_majmin/device/driver) + _driver=$(basename $_driver) + instmods $_driver + fi }

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[PATCH] kdumpctl: Add the command "kdumpctl showmem" to show the reserved memory
by Minfei Huang 14 Jun '15

14 Jun '15

If the grub kernel commandline is set to crashkernel=auto, it will not expand the crashkernel=auto in the /proc/cmdline. It still says crashkernel=auto. Using /sys to determines crashkernel actual size is confusing since there is no unit of measure. Add a new command "kdumpctl showmem" to show the reserved memory kindly. Signed-off-by: Minfei Huang <mhuang(a)redhat.com> Acked-by: Vivek Goyal <vgoyal(a)redhat.com> --- kdumpctl | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/kdumpctl b/kdumpctl index ca053a1..4f3c60d 100755 --- a/kdumpctl +++ b/kdumpctl @@ -551,6 +551,17 @@ propagate_ssh_key() fi } +show_reserved_mem() +{ + local mem_reserved=$(cat /sys/kernel/kexec_crash_size) + if [ $mem_reserved -eq 0 ] + then + echo "No memory reserved for crash kernel." + return + fi + echo "The kdump service reserved memory is `expr $mem_reserved / 1024 / 1024`MB" +} + is_fadump_capable() { # Check if firmware-assisted dump is enabled @@ -924,8 +935,11 @@ main () propagate) propagate_ssh_key ;; + showmem) + show_reserved_mem + ;; *) - echo $"Usage: $0 {start|stop|status|restart|propagate}" + echo $"Usage: $0 {start|stop|status|restart|propagate|showmem}" exit 1 esac } -- 1.9.3

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Question: is there any automated way of building rpm package?
by HATAYAMA Daisuke 04 Jun '15

04 Jun '15

Hello, Is there any automated way of building rpm package? That is, installing files such eppic, kexec-tools-po, makedumpfile and kexec-tools with expected file names necessary for installation, place them proper file path location and then execute rpmbuild command. I first found out there's no Makefile and INSTALL file, and then I tried preparing them manually in an ad-hoc way, but faced build failure several times and gave up. -- Thanks. HATAYAMA, Daisuke

2 2

[PATCH V3] Disable transparent hugepages in second kernel
by Li Wang 03 Jun '15

03 Jun '15

Transparent hugepages are on by default. Disable it in kdump kernel by adding the parameter 'transparent_hugepage=never'. This might help us with some of the memory issues we are facing. >From my test on two arch, not only there are no any bad effect on saving vmcore after turn off THP, but also we can get more 'MemAvailable:' in the kdump kernel. 1)x86_64 without the parameter ===================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.x86_64 root=/dev/mapper/rhel_ibm--x3250m4--01-root ro rd.lvm.lv=rhel_ibm-x3250m4-01/swap console=ttyS0,115200n8 rd.lvm.lv=rhel_ibm-x3250m4-01/root LANG=en_US.UTF-8 irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug disable_cpu_apicid=0 elfcorehdr=869764K kdump:/# cat /proc/meminfo MemTotal: 145492 kB MemFree: 68284 kB MemAvailable: 111632 kB <<------ Buffers: 36 kB Cached: 48184 kB ... added the parameter ===================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.x86_64 root=/dev/mapper/rhel_ibm--x3250m4--01-root ro rd.lvm.lv=rhel_ibm-x3250m4-01/swap console=ttyS0,115200n8 rd.lvm.lv=rhel_ibm-x3250m4-01/root LANG=en_US.UTF-8 irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never disable_cpu_apicid=0 elfcorehdr=869764K kdump:/# cat /proc/meminfo MemTotal: 145492 kB MemFree: 68388 kB MemAvailable: 111728 kB <<------- ... VmallocChunk: 34359659520 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ... 2)ppc64 without the parameter ==================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.ppc64 root=/dev/mapper/rhel_ibm--p8--05--lp6-root ro rd.lvm.lv=rhel_ibm-p8-05-lp6/root rd.lvm.lv=rhel_ibm-p8-05-lp6/swap LANG=en_US.UTF-8 irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 elfcorehdr=154880K kdump:/# cat /proc/meminfo MemTotal: 480832 kB MemFree: 293952 kB MemAvailable: 427840 kB <<-------- mallocUsed: 23680 kB VmallocChunk: 8589901824 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ... added the parameter =================== kdump:/# cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.10.0-229.el7.ppc64 root=/dev/mapper/rhel_ibm--p8--05--lp6-root ro rd.lvm.lv=rhel_ibm-p8-05-lp6/root rd.lvm.lv=rhel_ibm-p8-05-lp6/swap LANG=en_US.UTF-8 irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never elfcorehdr=154880K kdump:/# cat /proc/meminfo MemTotal: 480832 kB MemFree: 294592 kB MemAvailable: 428480 kB <<------- ... HugePages_Total: 0 Signed-off-by: Li Wang <liwang(a)redhat.com> --- kdump.sysconfig.i386 | 2 +- kdump.sysconfig.ppc64 | 2 +- kdump.sysconfig.ppc64le | 2 +- kdump.sysconfig.s390x | 2 +- kdump.sysconfig.x86_64 | 2 +- 5 files changed, 5 insertions(+), 5 deletions(-) diff --git a/kdump.sysconfig.i386 b/kdump.sysconfig.i386 index 84b2447..bb7a6e5 100644 --- a/kdump.sysconfig.i386 +++ b/kdump.sysconfig.i386 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2 panic=10 rootflags=nofail transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.ppc64 b/kdump.sysconfig.ppc64 index 5295626..dd09598 100644 --- a/kdump.sysconfig.ppc64 +++ b/kdump.sysconfig.ppc64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0" +KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.ppc64le b/kdump.sysconfig.ppc64le index 5295626..dd09598 100644 --- a/kdump.sysconfig.ppc64le +++ b/kdump.sysconfig.ppc64le @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0" +KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.s390x b/kdump.sysconfig.s390x index 745dd27..b103a88 100644 --- a/kdump.sysconfig.s390x +++ b/kdump.sysconfig.s390x @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="nr_cpus=1 cgroup_disable=memory numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="nr_cpus=1 cgroup_disable=memory numa=off udev.children-max=2 panic=10 rootflags=nofail transparent_hugepage=never" # Any additional /sbin/mkdumprd arguments required. MKDUMPRD_ARGS="" diff --git a/kdump.sysconfig.x86_64 b/kdump.sysconfig.x86_64 index d9ad9b5..7991d68 100644 --- a/kdump.sysconfig.x86_64 +++ b/kdump.sysconfig.x86_64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty -- 1.8.3.1

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[PATCH] mkdumprd: Fix the bug to get persistent device correctly
by Minfei Huang 01 Jun '15

01 Jun '15

One filesystem has an unique uuid to detect itself. For btrfs, several diskes can have the same uuid, and the soft link /dev/disk/by-uuid/$uuid points the only one disk which is contained in the btrfs. It may fails to filter out the disk by uuid, although there is a filesystem on the disk, like btrfs. In order to get the persistent device, we can use command "blkid". Signed-off-by: Minfei Huang <mhuang(a)redhat.com> --- mkdumprd | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/mkdumprd b/mkdumprd index 4d251ba..5fb578b 100644 --- a/mkdumprd +++ b/mkdumprd @@ -27,14 +27,14 @@ perror() { } get_persistent_dev() { - local i _tmp _dev + local i _tmp _dev _uuid _dev=$(udevadm info --query=name --name="$1" 2>/dev/null) [ -z "$_dev" ] && { perror_exit "Kernel dev name of $1 is not found." } - for i in /dev/mapper/* /dev/disk/by-uuid/* /dev/disk/by-id/*; do + for i in /dev/mapper/* /dev/disk/by-id/*; do _tmp=$(udevadm info --query=name --name="$i" 2>/dev/null) if [ "$_tmp" = "$_dev" ]; then echo $i @@ -42,6 +42,18 @@ get_persistent_dev() { fi done + if [ "x" != "x""$(blkid $1 | grep "UUID")" ]; then + _uuid=`blkid $1 | grep "UUID" | awk '{print $2}'` + _uuid=${_uuid#*\"} + _uuid=${_uuid%\"*} + _dev=/dev/disk/by-uuid/$_uuid + _tmp=$(udevadm info --query=name --name=$_dev 2>/dev/null) + if [ "x" != "x"$_tmp ]; then + echo $_dev + return + fi + fi + perror "WARNING: Persistent device name of $1 not found. Using $1 as dump target name" echo $1 } -- 1.9.3

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[PATCH] make kdump work when kernel crash after shutdown
by Chao Fan 27 May '15

27 May '15

In RHEL6, vmcore file was created if panic occurred during shutdown. This was very useful for analyzing problems during the shutdown sequence. However, in RHEL7, vmcore will not be created after kdump service is stopped. This will make it very difficult to solve problems during shutodwn. The reason why kdump fails to dump vmcore is kdump is stopped too early during the power is off. If add "DefaultDependencies=no" to the [Unit] of kdump.service , kdump will not be stopped by systemd after shutdown command. The manpage of systemd.unit about the DefaultDependencies: If true, (the default), a few default dependencies will implicitly be created for the unit. The actual dependencies created depend on the unit type. For example, for service units, these dependencies ensure that the service is started only after basic system initialization is completed and is properly terminated on system shutdown. The manpage about basic.target: A special target unit covering basic boot-up. systemd automatically adds dependencies of the types Requires= and After= for this target unit to all services (except for those with DefaultDependencies=no). Usually this should pull-in all mount points, swap devices, sockets, timers, and path units and other basic initialization necessary for general purpose daemons. So "DefaultDependencies=no" can keep kdump not stopped too early. But to make it start when power on, add After=basic.target will be better. The systemd-devel mailed to me: using DefaultDependencies=no but also After=basic.target will make sure the service isn't started too early (but kept until systemd's final process killing spree). Signed-off-by: Chao Fan <cfan(a)redhat.com> --- kdump.service | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kdump.service b/kdump.service index 24c1386..5144597 100644 --- a/kdump.service +++ b/kdump.service @@ -1,6 +1,7 @@ [Unit] Description=Crash recovery kernel arming -After=network.target network-online.target remote-fs.target +After=network.target network-online.target remote-fs.target basic.target +DefaultDependencies=no [Service] Type=oneshot -- 2.1.0

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[PATCH RESEND] mkdumprd: Fix the bug to get persistent device correctly
by Minfei Huang 20 May '15

20 May '15

1 0

[PATCH V2] Disable transparent hugepages in second kernel
by Li Wang 18 May '15

18 May '15

Transparent hugepages are on by default. Disable it in kdump kernel by adding parameter transparent_hugepage=never. This might help us with some of the memory issues we are facing. Signed-off-by: Li Wang <liwang(a)redhat.com> --- kdump.sysconfig.i386 | 2 +- kdump.sysconfig.ppc64 | 2 +- kdump.sysconfig.ppc64le | 2 +- kdump.sysconfig.s390x | 2 +- kdump.sysconfig.x86_64 | 2 +- 5 files changed, 5 insertions(+), 5 deletions(-) diff --git a/kdump.sysconfig.i386 b/kdump.sysconfig.i386 index 84b2447..bb7a6e5 100644 --- a/kdump.sysconfig.i386 +++ b/kdump.sysconfig.i386 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices numa=off udev.children-max=2 panic=10 rootflags=nofail transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.ppc64 b/kdump.sysconfig.ppc64 index 5295626..dd09598 100644 --- a/kdump.sysconfig.ppc64 +++ b/kdump.sysconfig.ppc64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0" +KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.ppc64le b/kdump.sysconfig.ppc64le index 5295626..dd09598 100644 --- a/kdump.sysconfig.ppc64le +++ b/kdump.sysconfig.ppc64le @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0" +KDUMP_COMMANDLINE_APPEND="irqpoll maxcpus=1 noirqdistrib reset_devices cgroup_disable=memory numa=off udev.children-max=2 ehea.use_mcs=0 panic=10 rootflags=nofail kvm_cma_resv_ratio=0 transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty diff --git a/kdump.sysconfig.s390x b/kdump.sysconfig.s390x index 745dd27..b103a88 100644 --- a/kdump.sysconfig.s390x +++ b/kdump.sysconfig.s390x @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="nr_cpus=1 cgroup_disable=memory numa=off udev.children-max=2 panic=10 rootflags=nofail" +KDUMP_COMMANDLINE_APPEND="nr_cpus=1 cgroup_disable=memory numa=off udev.children-max=2 panic=10 rootflags=nofail transparent_hugepage=never" # Any additional /sbin/mkdumprd arguments required. MKDUMPRD_ARGS="" diff --git a/kdump.sysconfig.x86_64 b/kdump.sysconfig.x86_64 index d9ad9b5..7991d68 100644 --- a/kdump.sysconfig.x86_64 +++ b/kdump.sysconfig.x86_64 @@ -16,7 +16,7 @@ KDUMP_COMMANDLINE="" # This variable lets us append arguments to the current kdump commandline # As taken from either KDUMP_COMMANDLINE above, or from /proc/cmdline -KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug" +KDUMP_COMMANDLINE_APPEND="irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off numa=off udev.children-max=2 panic=10 rootflags=nofail acpi_no_memhotplug transparent_hugepage=never" # Any additional kexec arguments required. In most situations, this should # be left empty -- 1.8.3.1

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[PATCH] Disable transparent hugepages in second kernel
by Li Wang 18 May '15

18 May '15

3 5

[PATCH v5] Filtered out "noauto" options in 2nd kernel fstab
by Qiao Zhao 14 May '15

14 May '15

Customer found when specify "noauto" option in fstab for nfs mount, dump failed. The reason is if "noauto" option is specified in fstab, the mount entry in fstab related to dump target will passed to dracut and stored in kdump initrd. Then during kdump kernel boots this entry containing "noauto" will be ignored by mount service. This cause dump failing. In fact with "noauto" not only nfs dump will fail, non-root disk dump will fail too. root disk dump can dump successfully since root disk can always be mounted by systemd. So now "noauto" need be filtered out when the fstab entry corresponding to dump target contains "noauto". Changelog: v4 -> v5 code comment is not clear enough. supplement it. --- mkdumprd | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mkdumprd b/mkdumprd index 4d251ba..b64276e 100644 --- a/mkdumprd +++ b/mkdumprd @@ -114,6 +114,9 @@ to_mount() { _fstype=$(findmnt -k -f -n -r -o FSTYPE $_dev) _options=$(findmnt --fstab -f -n -r -o OPTIONS $_dev) [ -z "$_options" ] && _options=$(findmnt -k -f -n -r -o OPTIONS $_dev) + # with 'noauto' in fstab nfs and non-root disk mount will fail in 2nd + # kernel, filter it out here. + _options=$(echo $_options | sed 's/noauto//') _options=${_options/#ro/rw} #mount fs target as rw in 2nd kernel # "x-initrd.mount" mount failure will trigger isolate emergency service # W/o this, systemd won't isolate, thus we won't get to emergency. -- 1.9.3

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