Your message dated Thu, 9 Feb 2023 14:13:40 +0000 (UTC)
with message-id <[email protected]>
and subject line Close duplicate
has caused the Debian Bug report #1030925,
regarding general: DHCP request bug when storage lost
to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact [email protected]
immediately.)
--
1030925: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1030925
Debian Bug Tracking System
Contact [email protected] with problems
--- Begin Message ---
Package: isc-dhcp-client
Version: 4.4.3-P1-1.1
Followup-For: Bug #932769
X-Debbugs-Cc: [email protected]
Hi,
We experience this issue too, in Bullseye and Bookworm (updated from
Bullseye).
Our environment is similar to that described by Mark (the initial
reporter), i.e., a VMware ESXi cluster with VMs stored on a network
storage. In our case, if the network storage becomes full, VMs get disk
IO errors and mark file systems as read-only.
After that, the DHCP client starts requesting and declining IP addresses
in a rapid manner. Leased addresses stay configured on the VMs' network
interfaces, which leads to DHCP pool exhaustion.
What happens in details:
- The DHCP client requests and receives an IP address.
- It runs the script /sbin/dhclient-script.
- The script configures a network interface.
- Next the script updates the /etc/resolv.conf file.
For this, it calls the wait_for_rw function to check if it can write
to /etc/resolv.conf.<shell PID>.
- If a file system is read only this check doesn't work as expected.
The script fails and exits with a non-zero code once it hits the
following line in wait_for_rw():
while ! { : >> "$file"; } 2>/dev/null;
- So the script exits, but the network interface still has leased IP
address.
- When DHCP client gets a non-zero code from the script, it sends
DHCPDECLINE to a DHCP server.
- The DHCP server abandons the IP address. It might try to reuse it
later by performing a ping check but the misbehaving DHCP client will
respond to it.
The script is executed by Dash (being /bin/sh) and its behavior complies
with POSIX:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_08_01,
"Redirection error with special built-in utilities" - "shall exit" for
non-interactive shells.
The error doesn't occur if the script executed by Bash. Currently we
test a simple Bash wrapper script as a workaround:
#!/bin/bash
source /sbin/dhclient-script
The problem can be reproduced by issuing "echo 1 >
/sys/block/sda/device/delete" on a test machine to remove the disk (sda
here) from the kernel.
-- System Information:
Debian Release: bookworm/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Kernel: Linux 6.1.0-3-amd64 (SMP w/2 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not
set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages isc-dhcp-client depends on:
ii debianutils 5.7-0.4
ii iproute2 6.1.0-1
ii libc6 2.36-8
Versions of packages isc-dhcp-client recommends:
ii isc-dhcp-common 4.4.3-P1-1.1
Versions of packages isc-dhcp-client suggests:
pn avahi-autoipd <none>
pn isc-dhcp-client-ddns <none>
pn resolvconf <none>
--- End Message ---
--- Begin Message ---
Sorry, I meant to add a comment to #932769, not to create a new bug report.
--- End Message ---
