Marco Ferrara's questions

Estou tentando atualizar meu jumphost do Ubuntu 20.04 para o Ubuntu 24.04.2 LTS, com auditoria habilitada.

Esta é minha conf:

$ cat /etc/audit/rules.d/000.audit.rules
-D
-b 64
-r 1000
-f 1

# Logging All user commands
-a always,exit -F arch=b64 -S execve -F auid>=1000 -F auid!=4294967295 -k user_commands
-a always,exit -F arch=b32 -S execve -F auid>=1000 -F auid!=4294967295 -k user_commands

...

Mas quando os usuários efetuam login no sistema (40-70 usuários), notei que o sistema consome toda a RAM, já que o uso da RAM é feito pelos buffers do kernel, que são usados ​​devido a um limite de taxa, o que leva à degradação do sistema até o congelamento.

$ grep -E 'Slab|SReclaimable|SUnreclaim' /proc/meminfo && free -m
Slab:            2690568 kB
SReclaimable:      14672 kB
SUnreclaim:      2675896 kB
               total        used        free      shared  buff/cache   available
Mem:            2972        2961          70           0          56          10
Swap:           4521         467        4054

Isso não acontece no Ubuntu 20.
Alguém tem ideia de como consertar?

Obrigado pela ajuda.

Estou tentando configurar um servidor Ubuntu 22.04 com duas redes, uma com ipv4 e outra com ipv6 (dual stack).

este é o meu /etc/network/interfaces (o endereço ipv6 no meu arquivo está correto, aqui eu substituí)

# The loopback network interface
auto lo
iface lo inet loopback

auto be0
iface be0 inet static
  address 10.0.100.138
  netmask 255.255.255.192
  network 10.0.100.128
  broadcast 10.0.100.191
  gateway 10.0.100.129

  post-up ip route flush cache
  post-down ip route flush cache
  post-up sleep 10s && ping -q -c 60 10.0.100.129 > /dev/null 2>&1 || true &

iface be0 inet6 static
  pre-up modprobe ipv6
  address 0x00:x00:000:0000::4
  netmask 64

  post-up ip -6 route add table be default via 0x00:x00:000:0000::1 dev be0
  post-up ip -6 route add table be 0x00:x00:000:0000::/64 dev be0 proto kernel scope link src 0x00:x00:000:0000::4
  post-up ip -6 rule add prio 10 from 0x00:x00:000:0000::4 lookup be
  pre-down ip -6 rule del from 0x00:x00:000:0000::4 lookup be
  pre-up ip -6 route flush table be
  post-up ip -6 route flush cache
  post-down ip -6 route flush cache

auto mgmt0
iface mgmt0 inet static
  address 10.0.100.44
  netmask 255.255.255.192
  network 10.0.100.0
  broadcast 10.0.100.63

  post-up ip route add table mgmt default via 10.0.100.1 dev mgmt0
  post-up ip route add table mgmt 10.0.100.0/26 dev mgmt0 proto kernel scope link src 10.0.100.44
  post-up ip rule add prio 20 from 10.0.100.44 lookup mgmt
  pre-down ip rule del from 10.0.100.44 lookup mgmt
  pre-up ip rule add prio 10000 to 10.245.253.29 lookup mgmt
  pre-down ip rule del to 10.245.253.29 lookup mgmt
  pre-up ip route flush table mgmt || /bin/true

  post-up ip route flush cache
  post-down ip route flush cache
  post-up sleep 10s && ping -q -c 60 10.0.100.1 > /dev/null 2>&1 || true &

mas networking.service retorna este erro:

# systemctl status networking.service
× networking.service - Raise network interfaces
     Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Mon 2023-11-13 10:54:09 GMT; 2min 57s ago
       Docs: man:interfaces(5)
    Process: 499 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=1/FAILURE)
   Main PID: 499 (code=exited, status=1/FAILURE)
        CPU: 142ms

Nov 13 10:54:09 test-jammyv6 systemd[1]: Starting Raise network interfaces...
Nov 13 10:54:09 test-jammyv6 ifup[574]: RTNETLINK answers: File exists
Nov 13 10:54:09 test-jammyv6 ifup[499]: ifup: failed to bring up be0
Nov 13 10:54:09 test-jammyv6 systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE
Nov 13 10:54:09 test-jammyv6 systemd[1]: networking.service: Failed with result 'exit-code'.
Nov 13 10:54:09 test-jammyv6 systemd[1]: Failed to start Raise network interfaces.

Posso consertar com os comandos:

root@test-jammyv6:~# systemctl status networking.service
× networking.service - Raise network interfaces
     Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Mon 2023-11-13 11:00:56 GMT; 35s ago
       Docs: man:interfaces(5)
    Process: 522 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=1/FAILURE)
   Main PID: 522 (code=exited, status=1/FAILURE)
        CPU: 136ms

Nov 13 11:00:56 test-jammyv6 systemd[1]: Starting Raise network interfaces...
Nov 13 11:00:56 test-jammyv6 ifup[573]: RTNETLINK answers: File exists
Nov 13 11:00:56 test-jammyv6 ifup[522]: ifup: failed to bring up be0
Nov 13 11:00:56 test-jammyv6 systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE
Nov 13 11:00:56 test-jammyv6 systemd[1]: networking.service: Failed with result 'exit-code'.
Nov 13 11:00:56 test-jammyv6 systemd[1]: Failed to start Raise network interfaces.
root@test-jammyv6:~# modprobe ipv6
root@test-jammyv6:~# ip -6 route add table be default via 0x00:x00:000:0000::1 dev be0
RTNETLINK answers: No route to host
root@test-jammyv6:~# ip -6 route add  default via 0x00:x00:000:0000::1 dev be0
RTNETLINK answers: No route to host
root@test-jammyv6:~# service networking restart
Job for networking.service failed because the control process exited with error code.
See "systemctl status networking.service" and "journalctl -xeu networking.service" for details.
root@test-jammyv6:~# ip addr flush dev be0
root@test-jammyv6:~# service networking restart
root@test-jammyv6:~# systemctl status networking.service
● networking.service - Raise network interfaces
     Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
     Active: active (exited) since Mon 2023-11-13 11:02:07 GMT; 2s ago
       Docs: man:interfaces(5)
    Process: 1035 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=0/SUCCESS)
   Main PID: 1035 (code=exited, status=0/SUCCESS)
      Tasks: 2 (limit: 9440)
     Memory: 688.0K
        CPU: 430ms
     CGroup: /system.slice/networking.service
             ├─1050 /bin/sh -c "sleep 10s && ping -q -c 60 10.0.100.129 > /dev/null 2>&1 || true &"
             └─1052 sleep 10s

Nov 13 11:02:05 test-jammyv6 systemd[1]: Starting Raise network interfaces...
Nov 13 11:02:07 test-jammyv6 ifup[1097]: Waiting for DAD... Done
Nov 13 11:02:07 test-jammyv6 systemd[1]: Finished Raise network interfaces.

Como consertar isso e ter uma configuração correta a cada reinicialização?