Re: [CentOS] How to specify kernel version when restart kdump
> -Original Messages- > From: wuzhouhui > Sent Time: 2019-03-29 10:06:06 (Friday) > To: "centos mailing list" > Cc: > Subject: Re: [CentOS] How to specify kernel version when restart kdump > > > -Original Messages- > > From: "Gianluca Cecchi" > > Sent Time: 2019-03-28 16:59:19 (Thursday) > > [...] > > The command line fo CentOS 6 clearly misses the kernel version to build > > initrd file for, so the correct command should be: > > > > /sbin/mkdumprd -d -f > > "/boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img" > > 2.6.32-642.13.1.el6.x86_64 > > Unfortunately, I encountered a new issue when mkdumprd for a kernel different from running. The phenomenon is mkdumprd cannot break following loop in function depsolve_modlist(), in /sbin/mkdumprd: 348 while [ -n "$TMPINMODS" ] 349 do 350for i in $TMPINMODS 351do 352 mname=`basename $i | sed -e's/\.ko//'` [...] 407 TMPINMODS=$TMPTMPMODS 408done 409 done 410 MODULES=$TMPOUTMODS and $TMPINMODS is vhost_net.ko when issue occurs. The reason is mkdumprd set $TMPINMODS by lsmod in running kernel. But there is a new depends of vhost_net in newer kernel and $TMPINMODS doesn't include it, so mkdumprd stuck in previous while loop. Is there a solution exists? > I test it and it works for me, although prints some harmless warnings. > > Thanks > ___ > CentOS mailing list > CentOS@centos.org > https://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] How to specify kernel version when restart kdump
> -Original Messages- > From: "Gianluca Cecchi" > Sent Time: 2019-03-28 16:59:19 (Thursday) > [...] > The command line fo CentOS 6 clearly misses the kernel version to build > initrd file for, so the correct command should be: > > /sbin/mkdumprd -d -f > "/boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img" 2.6.32-642.13.1.el6.x86_64 > I test it and it works for me, although prints some harmless warnings. Thanks ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] How to specify kernel version when restart kdump
On Thu, Mar 28, 2019 at 9:24 AM Gianluca Cecchi wrote: > > > 1) In CentOS 6 we have the classical SysV service > file: /etc/rc.d/init.d/kdump > > Supposing you have just installed 2.6.32-642.13.1.el6.x86_64 kernel > > [snip] > > and at the end it runs this command if it doesn't find one: > $MKDUMPRD $kdump_initrd $kdump_kver > > that tipically will translate in: > > /sbin/mkdumprd -d -f "/boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img" > > The command line fo CentOS 6 clearly misses the kernel version to build initrd file for, so the correct command should be: /sbin/mkdumprd -d -f "/boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img" 2.6.32-642.13.1.el6.x86_64 On a test system of mine with version 6.8: # /sbin/mkdumprd -d -f "/boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img" 2.6.32-642.13.1.el6.x86_64 Warning: There might not be enough space to save a vmcore. The size of UUID=359ce627-f3b1-49a3-a9b9-f607435a40d9 should be greater than 132250104 kilo bytes. # # ll /boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img -rw--- 1 root root 7515358 Mar 28 09:52 /boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] How to specify kernel version when restart kdump
On Thu, Mar 28, 2019 at 6:55 AM wuzhouhui
wrote:
> > -Original Messages-
> > From: "Benjamin Hauger"
> > Sent Time: 2019-03-28 01:31:40 (Thursday)
> > To: wuzhouhui , centos@centos.org
> > Cc:
> > Subject: Re: [CentOS] How to specify kernel version when restart kdump
> >
> > What do you mean? Wouldn't the kernel version always be the actual
> > running version of the kernel that was booted?
> >
> Suppose the running kernel is 2.6.32, and then I installed kernel 3.10.0.
> The files under /boot includes (exclude some unimportant files):
> initramfs-2.6.32.img
> initramfs-3.10.0.img
> vmlinuz-2.6.32
> vmlinuz-3.10.0
> initrd-2.6.32kdump.img
> We can see that there is no initrd-3.10.0kdump.img for newly installed
> kernel 3.10.0, and kdump will generate initrd-3.10.0kdump.img only when
> booted as kernel 3.10.0. However, I want kdump to generate
> initrd-3.10.0kdump.img
> now (the current running kernel is 2.6.32).
>
>
Your particolar versions seem quite strange because 2.6.32 lets me think
about CentOS 6 and 3.10.0 lets me think about CentOS 7.
Any way see below for some discussion, not tried by me, so in case please
use on test system before.
1) In CentOS 6 we have the classical SysV service
file: /etc/rc.d/init.d/kdump
Supposing you have just installed 2.6.32-642.13.1.el6.x86_64 kernel
Analyzing what it runs we have
DUMP_KERNELVER=""
MKDUMPRD_ARGS=""
. /etc/sysconfig/kdump
In my case:
KDUMP_BOOTDIR="/boot"
local running_kernel=`uname -r`
kdump_kver=`echo $running_kernel | sed 's/smp//g'`
MKDUMPRD="/sbin/mkdumprd -d -f $MKDUMPRD_ARGS"
kdump_initrd="${KDUMP_BOOTDIR}/initrd-${kdump_kver}kdump.img"
and at the end it runs this command if it doesn't find one:
$MKDUMPRD $kdump_initrd $kdump_kver
that tipically will translate in:
/sbin/mkdumprd -d -f "/boot/initrd-2.6.32-642.13.1.el6.x86_64kdump.img"
2) In CentOS 7 we have systemd unit files and for
kdump: /usr/lib/systemd/system/kdump.service
Supposing you have just installed 3.10.0-693.21.1.el7.x86_64
The script called actually it is /usr/bin/kdumpctl
See also fadump (firmware assisted dump) concepts in RHEL 7 / CentOS 7:
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/kernel_administration_guide/kernel_crash_dump_guide
But I think you are x86_64 so kdump sttill applies
In kdumpctl we have something like this:
MKDUMPRD="/sbin/mkdumprd -f"
TARGET_INITRD=""
. /lib/kdump/kdump-lib.sh
. /etc/sysconfig/kdump
eval $(cat /proc/cmdline| grep "BOOT_IMAGE" | cut -d' ' -f1)
KDUMP_BOOTDIR="/boot"$(dirname $BOOT_IMAGE)
kdump_kver=`uname -r`
TARGET_INITRD="${KDUMP_BOOTDIR}/initramfs-${kdump_kver}kdump.img"
rebuild_kdump_initrd()
{
$MKDUMPRD $TARGET_INITRD $kdump_kver
if [ $? != 0 ]; then
echo "mkdumprd: failed to make kdump initrd" >&2
return 1
fi
return 0
}
So at the end the command will be:
$MKDUMPRD $TARGET_INITRD $kdump_kver
that in general should be something like this if you want to compile for
kernel 3.10.0-693.21.1.el7.x86_64 :
/sbin/mkdumprd -f /boot/initramfs-3.10.0-693.21.1.el7.x86_64kdump.img
3.10.0-693.21.1.el7.x86_64
HIH trying,
Gianluca
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Re: [CentOS] How to specify kernel version when restart kdump
> -Original Messages- > From: "Benjamin Hauger" > Sent Time: 2019-03-28 01:31:40 (Thursday) > To: wuzhouhui , centos@centos.org > Cc: > Subject: Re: [CentOS] How to specify kernel version when restart kdump > > What do you mean? Wouldn't the kernel version always be the actual > running version of the kernel that was booted? > Suppose the running kernel is 2.6.32, and then I installed kernel 3.10.0. The files under /boot includes (exclude some unimportant files): initramfs-2.6.32.img initramfs-3.10.0.img vmlinuz-2.6.32 vmlinuz-3.10.0 initrd-2.6.32kdump.img We can see that there is no initrd-3.10.0kdump.img for newly installed kernel 3.10.0, and kdump will generate initrd-3.10.0kdump.img only when booted as kernel 3.10.0. However, I want kdump to generate initrd-3.10.0kdump.img now (the current running kernel is 2.6.32). > Ben > > On 3/26/19 6:16 PM, wuzhouhui wrote: > >> -Original Messages- > >> From: "Benjamin Hauger" > >> Sent Time: 2019-03-27 00:15:21 (Wednesday) > >> To: centos@centos.org > >> Cc: > >> Subject: Re: [CentOS] How to specify kernel version when restart kdump > >> > >> kdump operates by booting a fresh kernel to capture the context of a > >> crashed kernel, and so the only way for kdump to dump a kernel is to > >> crash it and cause kdump to invoke its post-crash kernel. > >> > >> You can manually force a running kernel to panic (and invoke a > >> correctly-configured kdump) with the following command sequence: > >> > >>> echo 1 > /proc/sys/kernel/sysrq > >>> echo c > /proc/sysrq-trigger > >> > >> Cheers, > >> Ben > > Hi, Ben > > > > I think your response doesn't answered my question. I'm not asking > > how to trigger kernel crash and see whether the kdump is works, but > > asking how to specifying kernel version when start kdump service. > > > > Thanks. > >> > >> > >> On 3/25/19 7:19 PM, wuzhouhui wrote: > >> CentOS@centos.org > >> https://lists.centos.org/mailman/listinfo/centos > > ___ > > CentOS mailing list > > CentOS@centos.org > > https://lists.centos.org/mailman/listinfo/centos > > > > -- > > Benjamin Hauger > SysAdmin/CSDC-DMO > Rm. 94 > x8371 ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] How to specify kernel version when restart kdump
What do you mean? Wouldn't the kernel version always be the actual running version of the kernel that was booted? Ben On 3/26/19 6:16 PM, wuzhouhui wrote: -Original Messages- From: "Benjamin Hauger" Sent Time: 2019-03-27 00:15:21 (Wednesday) To: centos@centos.org Cc: Subject: Re: [CentOS] How to specify kernel version when restart kdump kdump operates by booting a fresh kernel to capture the context of a crashed kernel, and so the only way for kdump to dump a kernel is to crash it and cause kdump to invoke its post-crash kernel. You can manually force a running kernel to panic (and invoke a correctly-configured kdump) with the following command sequence: echo 1 > /proc/sys/kernel/sysrq echo c > /proc/sysrq-trigger Cheers, Ben Hi, Ben I think your response doesn't answered my question. I'm not asking how to trigger kernel crash and see whether the kdump is works, but asking how to specifying kernel version when start kdump service. Thanks. On 3/25/19 7:19 PM, wuzhouhui wrote: CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos -- Benjamin Hauger SysAdmin/CSDC-DMO Rm. 94 x8371 ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] How to specify kernel version when restart kdump
> -Original Messages- > From: "Benjamin Hauger" > Sent Time: 2019-03-27 00:15:21 (Wednesday) > To: centos@centos.org > Cc: > Subject: Re: [CentOS] How to specify kernel version when restart kdump > > kdump operates by booting a fresh kernel to capture the context of a > crashed kernel, and so the only way for kdump to dump a kernel is to > crash it and cause kdump to invoke its post-crash kernel. > > You can manually force a running kernel to panic (and invoke a > correctly-configured kdump) with the following command sequence: > > > echo 1 > /proc/sys/kernel/sysrq > > echo c > /proc/sysrq-trigger > > Cheers, > Ben Hi, Ben I think your response doesn't answered my question. I'm not asking how to trigger kernel crash and see whether the kdump is works, but asking how to specifying kernel version when start kdump service. Thanks. > > > On 3/25/19 7:19 PM, wuzhouhui wrote: > CentOS@centos.org > https://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] How to specify kernel version when restart kdump
kdump operates by booting a fresh kernel to capture the context of a crashed kernel, and so the only way for kdump to dump a kernel is to crash it and cause kdump to invoke its post-crash kernel. You can manually force a running kernel to panic (and invoke a correctly-configured kdump) with the following command sequence: echo 1 > /proc/sys/kernel/sysrq echo c > /proc/sysrq-trigger Cheers, Ben On 3/25/19 7:19 PM, wuzhouhui wrote: Hi, Is there a way to specify kernel version when (re)start kdump service? Suppose I have install a new kernel and kdump will generate kdump.img for new kernel in next boot. But I want kdump to generate kdump.img for new kernel immediately, is it possible? Thanks. ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos -- Benjamin Hauger SysAdmin/CSDC-DMO Rm. 94 x8371 ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
[CentOS] How to specify kernel version when restart kdump
Hi, Is there a way to specify kernel version when (re)start kdump service? Suppose I have install a new kernel and kdump will generate kdump.img for new kernel in next boot. But I want kdump to generate kdump.img for new kernel immediately, is it possible? Thanks. ___ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
