One more question. When you say VNWare integrated product. AFAIK vmware
have their own networking module in the kernel? Can you reproduce this
with some other virtualisation technology like kvm, qemu?
And one more question: do depending on who does the DHCP receival in the
VM (systemd? isc-dhcp-client? [...]?): shouldn't there be some rate
limiting sanity check in the DHCP client?
*t
On Tue, 23 Jul 2019, Tomas Pospisek wrote:
Package: general
Followup-For: Bug #932769
Could you privide a recipe on how to reproduce this? There's a lot of
very special setup below, that someone wwould need large amounts of time
to reporoduce I feel.
Is it possible to reduce the problem to something easily demonstratable?
This seems to be an important issue to me.
I think the problem here *might* be a kernel problem? Re-assign this to
kernel package?
When you say that it DoS'es the server then what does "top" say? What is
being DoS'ed? Is it the CPU?
*t
It would be truly cool, if you could provide more infos.
*t
To: Debian Bug Tracking System <sub...@bugs.debian.org>
Subject: general: DHCP request bug when storage lost
Date: Mon, 22 Jul 2019 14:48:00 -0600
Package: general
Severity: important
Tags: l10n
Dear Maintainer,
While doing unrelated storage testing for our VMware integrated product, we
purposefully recreated
a storage outage by removing the iSCSI initiators from the backing array
hosting the vmdk disk
images for the virtual machine.
Upon removal of uplinks to storage, the VM goes into a R/O file system state
after 5-10 minutes.
When storage initiators are brought back up and the LUNs are rescanned, the VM
begins to
rapidly request DHCP leases from an ISC DHCP server. This DoS's the server in
a way due
to the number of DHCPDECLINE errors, and the interface attempts to take and
discard IP's in a
rapid fashion.
This only seems to appear on this distribution, and I can't replicate the
behavior on Debian 9
or in a desktop environment.
-- System Information:
Debian Release: 10.0
APT prefers stable
APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.19.0-5-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
-- System Information:
Debian Release: 10.0
APT prefers stable
APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.19.0-5-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_CH.utf8, LC_CTYPE=de_CH.utf8 (charmap=UTF-8), LANGUAGE=de_CH:de
(charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled