This is a short document about how to setup kdump on live images. All
steps were tested on Fedora 25 Alpha LiveCD and saved vmcore captured
by kdump to a USB stick successfully.
Signed-off-by: Tong Li <tonli@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
V1 of the KASLR patch which was backported in 2.0.13-6 had wrong
calculation for page_offset. This patch takes the correct difference.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Fix Bug 925630 - kexec-tools: support for arm64
https://bugzilla.redhat.com/show_bug.cgi?id=925630
involves three things:
1. back porting upstream code to enable the function of kexec-tools on arm64
patchset backported from upstream:
commit abdfe97736f89d9bc73662b9134604b0229a599e
commit 522df5f7217fda01ece3f6ac3e9987b0320c2bb0
commit 217bcc00c9309416a6c6cd0584196559d28a9259
2. fix the arm related building issue by using autoreconf in spec file
3. patches to fix the issue of higher version gcc used by koji (not upstrem yet,
and the corresponding fix in kernel side is in other package)
kexec-tools-2.0.13-arm64-Add-support-for-additional-relocations-in-the-kexec-purgatory-code.patch
kexec-tools-2.0.13-arm64-Add-support-of-R_AARCH64_PREL32-relocation-in-.patch
[panand: apply patches in 3 of above paragraph]
Signed-off-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Since in Fedora 25 kernel kaslr is enabled (x86) but makedumpfile can not save
a correct vmcore, so it means kdump default setup will not work.
Pratyush posted a patch series to upstream which can fix the issue. Let's merge them in F25, will get the normal fixes after it being merged in upstream, we hopefully can rebase soon in rawhide.
This is an urgent fix for F25 since F25 freeze is this week.
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
We get following error on the systems that have everything built-in and no
initrd is used.
Kernel dev name of /dev/root is not found.
Dump target /dev/root is probably not mounted.
It happens because `df $path` gets /dev/root from /proc/self/mountinfo.
Fix this by identifying real target device when `df $path` returns
Filesystem as /dev/root.
Reported-and-tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Since we also check for mount point of $_target after if/else loop, so
there is no need to do the same thing specifically in else loop as well.
Remove those duplicate statement from else loop.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
On a diskless client /etc/fstab does not exist. Therefore check
modification time of this file for rebuild only if it exists.
Also use --fstab option with findmnt only when /etc/fstab exists.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
commit "28e8c4b5ac89 kdumpctl: Move file modification check logic in
check_system_modified()" copied file modification check logic instead of
moving.
Kill the duplicate logic from original calling function check_rebuild().
Signed-off-by: Pratyush Anand <panand@redhat.com>
Reviewed-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Fedora dracut-network version >= 044-117 must be installed to work with
this set of kexec-tools patches. Therefore adding dependency for them.
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Kdump explicitly adds "nfs" dracut module in case of nfs dumping,
actually in case of nfs dump, nfs is a mount target, and will be
added into host_fs_types[], thus dracut will add it automatically,
according to 95nfs/module-setup.sh check().
So, we can safely remove all the add_dracut_module "nfs".
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Update "kexec-kdump-howto" to illustrate the usage of special mount
information via "dracut_args".
Reviewed-by: Pratyush Anand <panand@redhat.com>
Suggested-by: Dave Young <dyoung@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
There are some complaints about nfs kdump that users must mount
nfs beforehand, which may cause some overhead to nfs server.
For example, there're thounsands of diskless clients deployed with
nfs dumping, each time the client is boot up, it will trigger
kdump rebuilding so will mount nfs, thus resulting in thousands
of nfs request concurrently imposed on the same nfs server.
We introduce a new way of specifying mount information via the
already-existent "dracut_args" directive(so avoid adding extra
directives in /etc/kdump.conf), we will skip all the filesystem
mounting and checking stuff for it. So it can be used in the
above-mentioned nfs scenario to avoid severe nfs server overhead.
Specifically, if there is any "--mount" information specified via
"dracut_args" in /etc/kdump.conf, always use it as the final mount
without any validation(mounting or checking like mount options,
fs size, etc), so users are expected to ensure its correctness.
NOTE:
-Only one mount target is allowed using "dracut_args" globally.
-Dracut will create <mountpoint> if it doesn't exist in kdump kernel,
<mountpoint> must be specified as an absolute path.
-Users should do a test first and ensure it works because kdump does
not prepare the mount or check all the validity.
Reviewed-by: Pratyush Anand <panand@redhat.com>
Suggested-by: Dave Young <dyoung@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Fedora dracut version >= 044-75 must be installed to work with this set of
kexec-tools patches. Therefore adding dependency for them.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Now dracut takes care to add module for active watchdog. Therefore we do
not need to pass iTCO_wdt and lpc_ich module in rd.driver.pre specifically
here.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Update howto with notes on dracut and kernel watchdog module handling.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
If state of a watchdog device is changed by an user after kdumpctl restart
then initramfs must be rebuilt on the basis of new watchdog status.
Testing:
-------------------------------------------------------
Initramfs wdt state
Prev Current Result
-------------------------------------------------------
Not Exist NA X Rebuild
Exist Inact Inact No Rebuild
Exist Inact Act Force Rebuild
Exist Act Inact Force Rebuild
Exist Act Act(Same wdt) No Rebuild
Exist Act Act(Diff wdt) Force Rebuild
Exist Act Module Removed Force Rebuild
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
If dracut watchdog module is enabled then, it includes kernel watchdog
module of active watchdog device in initramfs.
kdump.conf has an option to modify dracut_args. So, if an user passes "-a
watchdog" in dracut_args then dracut will add kernel watchdog module of
active watchdog device in initramfs.
Since, kexec-tools always requires to add kernel watchdog module of active
watchdog device in initramfs, therefore even when an user does not pass any
watchdog option and there exists at least one active watchdog device then
also kexec-tools adds "-a watchdog" in dracut args.
Therefore, if an user does not want to add kernel watchdog module in
initramfs then the person must pass "-o watchdog" in dracut_args.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Fix the typos and grammar problems in kdump.conf man page.
Reported-by: Donald Berry <dberry@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
The default action comment about "halt" is wrong, default action means
the action to perform after a vmcore saving failure.
Also there are lots of typos and incorrect expressions.
Fix them here as well.
[dyoung: fixed trailing whitespaces, drop unnecessary comments, change the
alignment.]
Reported-by: Donald Berry <dberry@redhat.com>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
There are several kinds of iSCSI mode rhel support currently.
- Pure hardware iSCSI
- iBFT iSCSI
- Pure software iSCSI
Except for the 1st one that firmware takes care of everything to
make it behave like a local disk, both iBFT and pure software iSCSI
mode need pass information to kdump kernel for configuring them
correctly.
Currently kdump takes iBFT mode as a software iSCSI and collects
the related information to set up software iSCSI in 2nd kernel,
though dracut can detect and collect information to set up iBFT
iSCSI of 2nd kernel. This brings up 2 problems:
1) Redundent information about the related iSCSI is collected. One
is done by kdump, the other is from dracut.
2) These 2 sessions of 2nd kernel for a certain session of 1st kernel
could contain two "ip=xxx" cmdline option. This will cause cmdline
handling error in dracut.
The 1st one is not critical while the 2nd is. In order to avoid above
2 problems, kdump need detect iBFT mode iSCSI and leave it to dracut.
This is what is done in this patch.
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Use our own code to get system total memory from /proc/meminfo because the
callback to pyanaconda sometimes cause installation hangs.
Signed-off-by: Dave Young <dyoung@redhat.com>
Resolves: BZ1348898
dracut-functions.sh defines a get_persistent_dev(). Earlier, we had another
local get_persistent_dev() in mkdumprd, however that was moved to
kdump-lib.sh, so that it can be reused in kdumpctl.
Since, dracut-module-setup.sh (which is dracut's
99kdumpbase/module-setup.sh) sources kdump-lib.sh. Therefore, once dracut
will execute 99kdumpbase module, it's own get_persistent_dev() function is
overwritten by kdump's version. If any other dracut module calls
get_persistent_dev() thereafter then, kdump's version is executed, which was
not expected.
Therefore rename kdump's get_persistent_dev() as kdump_get_persistent_dev()
to avoid any name contention.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
The ifcfg file name of <netif> under "/etc/sysconfig/network-scripts/"
may not be "ifcfg-<netif>". For example, for "enp0s25" we are able to
generate its ifcfg like "/etc/sysconfig/network-scripts/ifcfg-enp0s25test"
via network-manager. If we alway assume "ifcfg-<netif>" is there, we will
got the wrong result in some cases.
The issue can be resolved by using the new get_ifcfg_filename() introduced
by PATCH "kdump-lib: Add get_ifcfg_filename() to get the proper ifcfg file",
so we hereby change all the "ifcfg-<netif>" users to use get_ifcfg_filename().
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Previously, we assumed the ifcfg file of a network "interface" is
"/etc/sysconfig/network-scripts/ifcfg-<interface>", but actually
it is not the case.
For example, for network interface "enp0s25", we are able to
generate like "/etc/sysconfig/network-scripts/ifcfg-enp0s25-test"
for it via network-manager.
The "suffix" in "ifcfg-<suffix>" is actually a "configuration"
name not "interface" name, though normally we use the "interface"
name as its "configuration" name. You can refer to "man ifup"
for some detail.
So, this patch adds some assistant helpers to acquire the right
ifcfg file for an interface. Borrow some logic from script below:
"/etc/sysconfig/network-scripts/network-functions"
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Currently initramfs is rebuilt even when crash kernel memory is not
available and then latter on kdump service is failed.
Its better to fail during feasibility itself when crash memory is not
reserved.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
We do not have *.xz, *.gz as part of repositiry, so ignore them. They are
annoying during development period, specially when we want to modify all
changes using `git add -A`.
Also ignore *.swp, and *.rpm because many of such temporary files are
created during development and such files would not be the part of
repository.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
kdumpctl passes --device argument if dump target is a raw device. It passes
--mount argument if dump target is either mounted as nfs or as a bulk
device. When dump target device is a root device then it does not pass any
of the above two arguments.
After kdumpctl restart, if there is any change in file system which needs
different dracut arguments, then initramfs must be rebuild.
Modification in filesystem for a raw target does not affect dracut
arguments. So, we do not consider to check any modification if raw target
was specified in kdump.conf.
We might need to change dracut arguments if there is some changes in nfs
and ssh target related files. However, we do not consider them in this
patch.
We mainly consider changes in bulk target specified in kdump.conf. We also
consider changes in bulk and nfs file system, if there was no dump target
specified in kdump.conf but dump path is mounting such file systems.
So the initramfs must be rebuild if, either dump target's persistent path
or it's mount point or its file system type changes. If there is no dump
target specified then, both dump path and root path must mount same device,
otherwise rebuild should be triggered.
Some of the examples when we can need a rebuild:
-- "dump target" is specified as one of ext[234], xfs or btrfs. But after
kdump initramfs building its UUID is changed by reformatting.
-- "dump target" is specified as file system type fs1 (say ext3). But after
kdump initramfs building, user change it to fs2 (say ext4), probably by
a mkfs.ext4 executing on the target device.
-- "dump target" is not specified, but "dump path" mounts a device which
is different than device for root path and either UUID or file system type
is modified after kdump initramfs build.
-- "dump target" is not specified, but "dump path" mounts a nfs device and
nfs host path changes after kdump initramfs build.
Some testing:
Initial conditions:
-- No dump target specified
-- dump path (/var/crash) and root(/) are on same device
-- kdumpctl was already executed once after last modification in
/etc/kdump.conf
# kdumpctl restart
No rebuild
# mkfs.ext2 /dev/md0;mount /dev/md0 /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# kdumpctl restart
No rebuild
# umount /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# kdumpctl restart
No rebuild
# mount /dev/md0 /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# umount /var/crash;mkfs.ext4 /dev/md0;
# mount /dev/md0 /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# umount /var/crash;mkfs.ext4 /dev/mapper/fedora-swap
# mount /dev/mapper/fedora-swap /var/crash/
# kdumpctl restart
Rebuilt because "Detected change in File System"
# umount /var/crash;mkfs.btrfs /dev/mapper/fedora-swap -f
# mount /dev/mapper/fedora-swap /var/crash/
# kdumpctl restart
Rebuilt because "Detected change in File System"
# kdumpctl restart
No rebuild
# umount /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# mount /dev/mapper/fedora-swap /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# umount /var/crash;mkfs.minix /dev/md0
# mount /dev/md0 /var/crash/; kdumpctl restart
Rebuilt because "Detected change in File System"
# kdumpctl restart
No rebuild
# umount /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# mount 192.168.1.16:/nfsroot /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# umount /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# mount 192.168.1.16:/nfsroot /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
# kdumpctl restart
No rebuild
# umount /var/crash;mount 192.168.1.12:/nfsroot /var/crash/
# kdumpctl restart
Rebuilt because "Detected change in File System"
# umount /var/crash/;kdumpctl restart
Rebuilt because "Detected change in File System"
Added "raw /dev/md0" in /etc/kdump.conf
# kdumpctl restart
Rebuilt because "Detected change in /etc/kdump.conf"
# mkfs.ext4 /dev/md0 ;kdumpctl restart
No rebuild
Added "ext4 /dev/md0" in /etc/kdump.conf
# mkfs.ext4 /dev/md0;mount /dev/md0 /mnt
# mkdir /mnt/var;mkdir /mnt/var/crash; kdumpctl restart
Rebuilt because "Detected change in /etc/kdump.conf"
# umount /mnt;mkfs.ext4 /dev/md0;mount /dev/md0 /mnt
# mkdir /mnt/var;mkdir /mnt/var/crash; kdumpctl restart
Rebuilt because "Detected change in /etc/kdump.conf"
Most of the credits for this patch goes to Xunlei Pang <xpang@redhat.com>
for suggesting several improvements.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Baoquan He <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
to_dev_name() and get_persistent_dev() can be used by function in kdumpctl.
Therefore moving them to kdump-lib.sh.
No functional changes.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Baoquan He <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Relevant kdump files are also part of system. Therefore, moving logic of
file modification checking in check_system_modified() function now.
No functional changes.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Baoquan He <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
There could be some dynamic system modification, which may affect kdump
kernel boot process. In such situation initramfs must be rebuilt on the
basis of changes.
Since most of these checking methods will use information from
TARGET_INITRD, therefore check its existence in common code.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Baoquan He <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
raw devices are not mounted and also does not need to contain any
filesystem. So they may have UUIDs(when formatted) and may not have UUIDs
when raw. Therefore, do not look for persistent names by-uuid for raw
devices.
Signed-off-by: Pratyush Anand <panand@redhat.com>
Suggested-by: Dave Young <dyoung@redhat.com>
Acked-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Baoquan He <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
