Description of problem: Kdump can dump the vmcore to remote nfs target if kdump was configred by using nfs dump and nfs target was mounted before building kdump initramfs. But if we use hostname to configure nfs dump, Though the kdump service will start successfully, dump will fail because there isn't a /etc/hosts file in initramfs.
Resolution: copy /etc/hosts to initramfs.
Signed-off-by: arthur zzou@redhat.com --- mkdumprd | 1 + 1 file changed, 1 insertion(+)
diff --git a/mkdumprd b/mkdumprd index 6de1755..d18882a 100644 --- a/mkdumprd +++ b/mkdumprd @@ -520,6 +520,7 @@ do
if [ "$config_opt" = "nfs" ]; then add_dracut_module "nfs" + add_dracut_arg "--install" "/etc/hosts" fi add_mount "$config_val" mkdir_save_path_fs $config_val
On 12/09/13 at 04:45pm, Zhi Zou wrote:
Description of problem: Kdump can dump the vmcore to remote nfs target if kdump was configred by using nfs dump and nfs target was mounted before building kdump initramfs. But if we use hostname to configure nfs dump, Though the kdump service will start successfully, dump will fail because there isn't a /etc/hosts file in initramfs.
Resolution: copy /etc/hosts to initramfs.
I think it would be useful if we install /etc/hosts to kdump initramfs. But what I concern is when the host ip changed in /etc/hosts, a rebuild wouldn't be triggered, and in 2nd kernel, mount nfs server would fail.
Moreover, this seems like a dracut issue. dracut can mount nfs in initramfs and it does need /etc/hosts to look up for static configured hostname.
Signed-off-by: arthur zzou@redhat.com
mkdumprd | 1 + 1 file changed, 1 insertion(+)
diff --git a/mkdumprd b/mkdumprd index 6de1755..d18882a 100644 --- a/mkdumprd +++ b/mkdumprd @@ -520,6 +520,7 @@ do
if [ "$config_opt" = "nfs" ]; then add_dracut_module "nfs"
add_dracut_arg "--install" "/etc/hosts"
ssh dump is in the same situation here.
Thanks WANG Chao
fi add_mount "$config_val" mkdir_save_path_fs $config_val-- 1.8.4.2
kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
----- Original Message -----
On 12/09/13 at 04:45pm, Zhi Zou wrote:
Description of problem: Kdump can dump the vmcore to remote nfs target if kdump was configred by using nfs dump and nfs target was mounted before building kdump initramfs. But if we use hostname to configure nfs dump, Though the kdump service will start successfully, dump will fail because there isn't a /etc/hosts file in initramfs.
Resolution: copy /etc/hosts to initramfs.
I think it would be useful if we install /etc/hosts to kdump initramfs. But what I concern is when the host ip changed in /etc/hosts, a rebuild wouldn't be triggered, and in 2nd kernel, mount nfs server would fail.
Yes, That is really a problem.
Moreover, this seems like a dracut issue. dracut can mount nfs in initramfs and it does need /etc/hosts to look up for static configured hostname.
I think mkdumprd just add a "mount" argument and a "nfs" module in dracut when using nfs. The way dracut address the "mount" argument is add a entry in "${initdir}/etc/fstab. So if there isn't /etc/hosts in intramfs, the 2nd kernel still can't mount the target. What's more, /etc/hosts is not necessary for dracut nfs and ssh module. So I think the better way is test if we should install /etc/hosts to initramfs in mkdumprd.
Signed-off-by: arthur zzou@redhat.com
mkdumprd | 1 + 1 file changed, 1 insertion(+)
diff --git a/mkdumprd b/mkdumprd index 6de1755..d18882a 100644 --- a/mkdumprd +++ b/mkdumprd @@ -520,6 +520,7 @@ do
if [ "$config_opt" = "nfs" ]; then add_dracut_module "nfs"
add_dracut_arg "--install" "/etc/hosts"ssh dump is in the same situation here.
Yes, ssh should have the same problem.
Thanks WANG Chao
fi add_mount "$config_val" mkdir_save_path_fs $config_val-- 1.8.4.2
kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
On 12/09/13 at 09:37pm, Zhi Zou wrote:
----- Original Message -----
On 12/09/13 at 04:45pm, Zhi Zou wrote:
Description of problem: Kdump can dump the vmcore to remote nfs target if kdump was configred by using nfs dump and nfs target was mounted before building kdump initramfs. But if we use hostname to configure nfs dump, Though the kdump service will start successfully, dump will fail because there isn't a /etc/hosts file in initramfs.
Resolution: copy /etc/hosts to initramfs.
I think it would be useful if we install /etc/hosts to kdump initramfs. But what I concern is when the host ip changed in /etc/hosts, a rebuild wouldn't be triggered, and in 2nd kernel, mount nfs server would fail.
Yes, That is really a problem.
Moreover, this seems like a dracut issue. dracut can mount nfs in initramfs and it does need /etc/hosts to look up for static configured hostname.
I think mkdumprd just add a "mount" argument and a "nfs" module in dracut when using nfs. The way dracut address the "mount" argument is add a entry in "${initdir}/etc/fstab. So if there isn't /etc/hosts in intramfs, the 2nd kernel still can't mount the target.
That's exactly what I was talking about.
Think about the case of normal boot, if we want to mount such static hostname in initramfs, we still need /etc/hosts. That's why a normal boot and a kdump boot share the same concern in this case.
What's more, /etc/hosts is not necessary for dracut nfs and ssh module.
Why? Is it because dracut doesn't support static hostname or dracut just need to be fixed?
So I think the better way is test if we should install /etc/hosts to initramfs in mkdumprd.
If we really need /etc/hosts to do static hostname lookup, we should install it. If we don't need /etc/hosts because the hostname is a dynamic name configured by DNS server, it's harmless whether or not we install it.
I think I'd like to support what dracut supports (unless it's kdump specific stuff). So my idea is:
1. Try to fix it in dracut. Because this is not kdump only issue. 2. If we can't fix it in dracut, we can always encourage user to specify 'dracut_args --install /etc/hosts' in /etc/kdump.conf, when they want to use a static hostname.
Thanks WANG Chao
Signed-off-by: arthur zzou@redhat.com
mkdumprd | 1 + 1 file changed, 1 insertion(+)
diff --git a/mkdumprd b/mkdumprd index 6de1755..d18882a 100644 --- a/mkdumprd +++ b/mkdumprd @@ -520,6 +520,7 @@ do
if [ "$config_opt" = "nfs" ]; then add_dracut_module "nfs"
add_dracut_arg "--install" "/etc/hosts"ssh dump is in the same situation here.
Yes, ssh should have the same problem.
Thanks WANG Chao
fi add_mount "$config_val" mkdir_save_path_fs $config_val-- 1.8.4.2
kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
----- Original Message -----
On 12/09/13 at 09:37pm, Zhi Zou wrote:
----- Original Message -----
On 12/09/13 at 04:45pm, Zhi Zou wrote:
Description of problem: Kdump can dump the vmcore to remote nfs target if kdump was configred by using nfs dump and nfs target was mounted before building kdump initramfs. But if we use hostname to configure nfs dump, Though the kdump service will start successfully, dump will fail because there isn't a /etc/hosts file in initramfs.
Resolution: copy /etc/hosts to initramfs.
I think it would be useful if we install /etc/hosts to kdump initramfs. But what I concern is when the host ip changed in /etc/hosts, a rebuild wouldn't be triggered, and in 2nd kernel, mount nfs server would fail.
Yes, That is really a problem.
Moreover, this seems like a dracut issue. dracut can mount nfs in initramfs and it does need /etc/hosts to look up for static configured hostname.
I think mkdumprd just add a "mount" argument and a "nfs" module in dracut when using nfs. The way dracut address the "mount" argument is add a entry in "${initdir}/etc/fstab. So if there isn't /etc/hosts in intramfs, the 2nd kernel still can't mount the target.
That's exactly what I was talking about.
Think about the case of normal boot, if we want to mount such static hostname in initramfs, we still need /etc/hosts. That's why a normal boot and a kdump boot share the same concern in this case.
What's more, /etc/hosts is not necessary for dracut nfs and ssh module.
Why? Is it because dracut doesn't support static hostname or dracut just need to be fixed?
Seems like dracut doesn't support static hostname currently, at least I don't find any clue. That why I install /etc/hosts manually.
So I think the better way is test if we should install /etc/hosts to initramfs in mkdumprd.
If we really need /etc/hosts to do static hostname lookup, we should install it. If we don't need /etc/hosts because the hostname is a dynamic name configured by DNS server, it's harmless whether or not we install it.
I think I'd like to support what dracut supports (unless it's kdump specific stuff). So my idea is:
- Try to fix it in dracut. Because this is not kdump only issue.
- If we can't fix it in dracut, we can always encourage user to specify 'dracut_args --install /etc/hosts' in /etc/kdump.conf, when they want to use a static hostname.
Thanks WANG Chao
Signed-off-by: arthur zzou@redhat.com
mkdumprd | 1 + 1 file changed, 1 insertion(+)
diff --git a/mkdumprd b/mkdumprd index 6de1755..d18882a 100644 --- a/mkdumprd +++ b/mkdumprd @@ -520,6 +520,7 @@ do
if [ "$config_opt" = "nfs" ]; then add_dracut_module "nfs"
add_dracut_arg "--install" "/etc/hosts"ssh dump is in the same situation here.
Yes, ssh should have the same problem.
Thanks WANG Chao
fi add_mount "$config_val" mkdir_save_path_fs $config_val-- 1.8.4.2
kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
----- Original Message -----
----- Original Message -----
On 12/09/13 at 09:37pm, Zhi Zou wrote:
----- Original Message -----
On 12/09/13 at 04:45pm, Zhi Zou wrote:
Description of problem: Kdump can dump the vmcore to remote nfs target if kdump was configred by using nfs dump and nfs target was mounted before building kdump initramfs. But if we use hostname to configure nfs dump, Though the kdump service will start successfully, dump will fail because there isn't a /etc/hosts file in initramfs.
Resolution: copy /etc/hosts to initramfs.
I think it would be useful if we install /etc/hosts to kdump initramfs. But what I concern is when the host ip changed in /etc/hosts, a rebuild wouldn't be triggered, and in 2nd kernel, mount nfs server would fail.
Yes, That is really a problem.
Moreover, this seems like a dracut issue. dracut can mount nfs in initramfs and it does need /etc/hosts to look up for static configured hostname.
I think mkdumprd just add a "mount" argument and a "nfs" module in dracut when using nfs. The way dracut address the "mount" argument is add a entry in "${initdir}/etc/fstab. So if there isn't /etc/hosts in intramfs, the 2nd kernel still can't mount the target.
That's exactly what I was talking about.
Think about the case of normal boot, if we want to mount such static hostname in initramfs, we still need /etc/hosts. That's why a normal boot and a kdump boot share the same concern in this case.
What's more, /etc/hosts is not necessary for dracut nfs and ssh module.
Why? Is it because dracut doesn't support static hostname or dracut just need to be fixed?
Seems like dracut doesn't support static hostname currently, at least I don't find any clue. That why I install /etc/hosts manually.
So I think the better way is test if we should install /etc/hosts to initramfs in mkdumprd.
If we really need /etc/hosts to do static hostname lookup, we should install it. If we don't need /etc/hosts because the hostname is a dynamic name configured by DNS server, it's harmless whether or not we install it.
I think I'd like to support what dracut supports (unless it's kdump specific stuff). So my idea is:
- Try to fix it in dracut. Because this is not kdump only issue.
- If we can't fix it in dracut, we can always encourage user to specify 'dracut_args --install /etc/hosts' in /etc/kdump.conf, when they want to use a static hostname.
That is right! fixing it in dracut is better.
Thanks WANG Chao
Signed-off-by: arthur zzou@redhat.com
mkdumprd | 1 + 1 file changed, 1 insertion(+)
diff --git a/mkdumprd b/mkdumprd index 6de1755..d18882a 100644 --- a/mkdumprd +++ b/mkdumprd @@ -520,6 +520,7 @@ do
if [ "$config_opt" = "nfs" ]; then add_dracut_module "nfs"
add_dracut_arg "--install" "/etc/hosts"ssh dump is in the same situation here.
Yes, ssh should have the same problem.
Thanks WANG Chao
fi add_mount "$config_val" mkdir_save_path_fs $config_val-- 1.8.4.2
kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
kexec mailing list kexec@lists.fedoraproject.org https://lists.fedoraproject.org/mailman/listinfo/kexec
On Mon, Dec 09, 2013 at 11:31:30PM -0500, Zhi Zou wrote:
[..]
I think I'd like to support what dracut supports (unless it's kdump specific stuff). So my idea is:
- Try to fix it in dracut. Because this is not kdump only issue.
- If we can't fix it in dracut, we can always encourage user to specify 'dracut_args --install /etc/hosts' in /etc/kdump.conf, when they want to use a static hostname.
That is right! fixing it in dracut is better.
I don't think we need to include /etc/hosts. There should be tools/utitlities in dracut to dns resolve the name of host.
Agreed, this should if fixed in dracut (if it is an issue at all).
Thanks Vivek
----- Original Message -----
On Mon, Dec 09, 2013 at 11:31:30PM -0500, Zhi Zou wrote:
[..]
I think I'd like to support what dracut supports (unless it's kdump specific stuff). So my idea is:
- Try to fix it in dracut. Because this is not kdump only issue.
- If we can't fix it in dracut, we can always encourage user to
specify 'dracut_args --install /etc/hosts' in /etc/kdump.conf, when they want to use a static hostname.
That is right! fixing it in dracut is better.
I don't think we need to include /etc/hosts. There should be tools/utitlities in dracut to dns resolve the name of host.
But if we configure the hostname locally in /etc/hosts, for example arthur 10.66.17.35 then the dns server still can't resolve "arthur" to 10.66.17.35 because it don't have the information above.
Thanks Arthur
Agreed, this should if fixed in dracut (if it is an issue at all).
Thanks Vivek
-
Arthur Zou -
Vivek Goyal -
WANG Chao