--- title: "Completa l'intervento di manutenzione del tuo server dedicato (EN)" description: "Find out what actions you can carry out yourself on your server following a maintenance intervention" url: https://docs.ovhcloud.com/it/guides/bare-metal-cloud/dedicated-servers/intervention-support lang: it lastUpdated: 2026-03-20 --- # Completa l'intervento di manutenzione del tuo server dedicato (EN) ## Objective Our maintenance interventions are limited to the hardware aspect of your server. Following a maintenance intervention, actions may be required on your server’s software section. This guide, which is based on feedback received from our teams and use cases, lists the actions that need to be taken, depending on your installation: operating systems, hypervisor, etc. Its goal is to support you and ensure that there is as little impact as possible in the lifecycle of your environments. ## Requirements - A [dedicated server](https://www.ovhcloud.com/it/bare-metal/) in your OVHcloud account ## Instructions :::info Find out how to identify the names of your network interfaces in [this subpart of this guide](#network-interface). ::: Continue reading this guide by clicking on the link for your installation: - Operating system - [Ubuntu/Debian 12+](#ubuntu) - [CentOS/Alma Linux](#centos-almalinux) - [SmartOS](#smartos) - [FreeBSD](#freebsd) - [Gentoo](#gentoo) - Virtualisation - [Proxmox/Debian (excluding Debian 12+)](#proxmox) - [XenServer](#xenserver) - [ESXi](#esxi) - [Windows (hyper-V)](#windows) :::info If you experience an operating system boot problem that appears to be related to its EFI boot partition, go directly to this [section](#partition-efi). ::: [](#) ### Ubuntu/Debian 12+ If you are experiencing network connectivity issues (for example, no ping after a motherboard replacement), perform the following steps: 1. Reboot the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) . 2. Mount the partition `/` : ```bash root@rescue:~# mount /dev/my_system_disk /mnt ``` If the `70-persistent-net.rules` file does not exist (refer to the section of this guide on [the names of your network interfaces](#network-interface)), check the following files in the `/etc/systemd/network/` tree: - `50-default.network` - `50-public-interface.link` ```bash root@rescue:~# cat /mnt/etc/systemd/network/50-default.network # This file sets the IP configuration of the primary (public) network device. # You can also see this as "OSI Layer 3" config. # It was created by the OVH installer, please be careful with modifications. # Documentation: man systemd.network or https://www.freedesktop.org/software/systemd/man/systemd.network.html [Match] MACAddress=xx:xx:xx:xx:xx:xx [Network] Description=network interface on public network, with default route DHCP=no Address=1.2.3.4/24 Gateway=1.2.3.254 IPv6AcceptRA=no NTP=ntp.ovh.net DNS=127.0.0.1 DNS=213.186.33.99 DNS=2001:41d0:3:163::1 Gateway=2001:41d0:0203:4bff:ff:ff:ff:ff [Address] Address=2001:41d0:0203:1234::/64 [Route] Destination=2001:41d0:0203:4bff:ff:ff:ff:ff:ff Scope=link root@rescue:~# root@rescue:~# cat /mnt/etc/systemd/network/50-public-interface.link # This file configures the relation between network device and device name. # You can also see this as "OSI Layer 2" config. # It was created by the OVH installer, please be careful with modifications. # Documentation: man systemd.link or https://www.freedesktop.org/software/systemd/man/systemd.link.html [Match] MACAddress=xx:xx:xx:xx:xx:xx [Link] Description=network interface on public network, with default route MACAddressPolicy=persistent NamePolicy=kernel database onboard slot path mac #Name=eth2 # name under which this interface is known under OVH rescue system #Name=eno3 # name under which this interface is probably known by systemd root@rescue:~# ``` 3\. Save and edit the files to enter the new value for your MAC address: ```bash root@rescue:~# cp /mnt/etc/systemd/network/50-default.network /mnt/etc/systemd/network/50-default.network.link.bak-`date +%s` root@rescue:~# cp /mnt/etc/systemd/network/50-public-interface.link /mnt/etc/systemd/network/50-public-interface.link.bak-`date +%s` root@rescue:~# nano /mnt/etc/systemd/network/50-default.network root@rescue:~# cat /mnt/etc/systemd/network/50-default.network | grep MACAddress MACAddress=xx:xx:xx:xx:xx:xx root@rescue:~# root@rescue:~# nano /mnt/etc/systemd/network/50-public-interface.link root@rescue:~# root@rescue:~# cat /mnt/etc/systemd/network/50-public-interface.link | grep MACAddress MACAddress=xx:xx:xx:xx:xx:xx root@rescue:~# ``` 4\. Unmount the partition `/` before rebooting the server. #### Special cases In some cases, it is necessary to propagate the new MAC address to the following files: - `/mnt/etc/netplan/01-netcfg.yaml` - `/mnt/etc/netplan/50-cloud-init.yaml` - `/mnt/etc/systemd/network/10-eno1.link` - `/mnt/etc/systemd/network/10-eno1.network` [](#) ### CentOS/Alma Linux If you are experiencing network connectivity issues (for example, no ping after a motherboard replacement), perform the following steps: 1. Reboot the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) . 2. Mount the partition `/` : ```bash root@rescue:~# mount /dev/my_system_disk /mnt ``` 3\. Check the configuration file `/mnt/etc/sysconfig/network-scripts/ifcfg-eth0`. 4\. Back up the files and edit them to correct the MAC address: ```bash root@rescue:~# cp /mnt/etc/sysconfig/network-scripts/ifcfg-eth0 /mnt/etc/sysconfig/network-scripts/ifcfg-eth0.`date +%s` ``` 5\. Enter the new MAC address in the line `HWADDR=xx:xx:xx:xx:xx:xx`. 6\. Unmount the partition `/` before rebooting the server. [](#) ### SmartOS If you are experiencing network connectivity issues (for example, no ping after a motherboard replacement), perform the following steps: 1. Reboot the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) . ```bash modprobe zfs root@rescue:~# zpool import -f zones (zpool import to list the pools) root@rescue:~# zfs set mountpoint=/mnt zones/usbkey root@rescue:~# zfs mount zones/usbkey root@rescue:~# cp /mnt/config {,.bak-$(date +"%Y-%m-%d-%H_%M")} ``` 2\. Enter the new MAC address in the `admin_nic` line: ```bash root@rescue:~# vim /mnt/config ``` 3\. Do not forget to unmount the partitions before rebooting the server in `netboot` mode: ```bash root@rescue:~# zfs umount -a root@rescue:~# zfs set mountpoint=`/usbkey` zones/usbkey ``` [](#) ### FreeBSD If you are experiencing network connectivity issues (for example, no ping after a motherboard replacement), perform the following steps: 1. Reboot the server in rescue-bsd mode. 2. Run the `ifconfig` command from the rescue-bsd prompt. This way, you can identify the name of your network interface: ```bash root@rescue-bsd:~ # ifconfig igb0: flags=8843 metric 0 mtu 1500 options=403bb ether xx:xx:xx:xx:xx:xx ``` 3\. Run the `gpart show` command to locate and associate the partitions/names: ```bash root@rescue-bsd:~ # gpart show => 63 3907029105 ada0 MBR (1.8T) 63 3907029105 1 freebsd [active] (1.8T) => 0 3907029105 ada0s1 BSD (1.8T) 0 40960000 1 freebsd-ufs (20G) 40960000 3865020416 2 freebsd-ufs (1.8T) 3905980416 1048689 4 freebsd-swap (512M) => 63 3907029105 diskid/DISK-PN1134P6K14W5W MBR (1.8T) 63 3907029105 1 freebsd [active] (1.8T) => 0 3907029105 diskid/DISK-PN1134P6K14W5Ws1 BSD (1.8T) 0 40960000 1 freebsd-ufs (20G) 40960000 3865020416 2 freebsd-ufs (1.8T) 3905980416 1048689 4 freebsd-swap (512M) ``` 4\. Mount the partition you are interested in, you can modify the interface via the file `/etc/rc.conf`: ```bash root@rescue-bsd:~ # zpool import pool: zroot id: 16525429322000118320 state: ONLINE status: The pool was last accessed by another system. action: The pool can be imported using its name or numeric identifier and the '-f' flag. see: http://illumos.org/msg/ZFS-8000-EY config: zroot ONLINE ada0p4 ONLINE root@rescue-bsd:~ # root@rescue-bsd:~ # root@rescue-bsd:~ # zpool import -f zroot cannot mount '/home': failed to create mountpoint cannot mount '/zroot': failed to create mountpoint root@rescue-bsd:~ # root@rescue-bsd:~ # zfs list -t all NAME USED AVAIL REFER MOUNTPOINT zroot 1.01G 673G 88K /zroot zroot/ROOT 1.00G 673G 88K none zroot/ROOT/default 1.00G 18.5G 1.00G / zroot/home 88K 673G 88K /home root@rescue-bsd:~ # mkdir /tmp/rootClient root@rescue-bsd:~ # zfs set mountpoint=/tmp/roo mountpoint=/tmp/ not found root@rescue-bsd:~ # zfs set mountpoint=/tmp/rootClient zroot/ROOT/default root@rescue-bsd:~ # zfs list -t all NAME USED AVAIL REFER MOUNTPOINT zroot 1.01G 673G 88K /zroot zroot/ROOT 1.00G 673G 88K none zroot/ROOT/default 1.00G 18.5G 1.00G /tmp/rootClient zroot/home 88K 673G 88K /home root@rescue-bsd:~ # root@rescue-bsd:~ # zfs mount zroot/ROOT/default root@rescue-bsd:~ # ls /tmp/rootClient/ .cshrc .rnd bin boot.config entropy home libexec mnt opt rescue sbin tmp var .profile COPYRIGHT boot dev etc lib media net proc root sys usr zroot root@rescue-bsd:~ # ``` 5\. Back up the files and edit them to correct the MAC address. In this case, we need to modify the 3 instances of `em0` by `ibg0` from the associated configuration file: ```bash root@rescue-bsd:~ # mount /dev/ada0s1 /mnt/ root@rescue-bsd:~ # root@rescue-bsd:~ # cat /mnt/etc/rc.conf sshd_enable="YES" # Set dumpdev to "AUTO" to enable crash dumps, "NO" to disable dumpdev="AUTO" local_unbound_enable=yes ifconfig_em0="inet xx.xxx.xxx.xxx netmask 255.255.255.0 broadcast xx.xxx.xxx.255" defaultrouter="xx.xxx.xxx.254" # IPv6 configuration ipv6_enable="YES" ipv6_network_interfaces="em0" ifconfig_em0_ipv6="inet6 2001:xxxx:xxxx:xxx::1 prefixlen 128 accept_rtadv no_radr" ipv6_static_routes="ovhgw" ipv6_route_ovhgw="2001:41d0:0001:c1ff:ff:ff:ff:ff -prefixlen 128 -interface em0" ipv6_defaultrouter="2001:41d0:0001:c1ff:ff:ff:ff:ff" mysql_enable="YES" root@rescue-bsd:~ # root@rescue-bsd:~ # cp /mnt/etc/rc.conf /mnt/etc/rc.conf.`date +%s` root@rescue-bsd:~ # root@rescue-bsd:~ # vim /mnt/etc/rc.conf root@rescue-bsd:~ # root@rescue-bsd:~ # cat /mnt/etc/rc.conf sshd_enable="YES" # Set dumpdev to "AUTO" to enable crash dumps, "NO" to disable dumpdev="AUTO" local_unbound_enable=yes ifconfig_ibg0="inet xx.xxx.xxx.xxx netmask 255.255.255.0 broadcast xx.xxx.xxx.255" defaultrouter="xx.xxx.xxx.254" # IPv6 configuration ipv6_enable="YES" ipv6_network_interfaces="em0" ifconfig_ibg0_ipv6="inet6 2001:xxxx:xxxx:xxxx::1 prefixlen 128 accept_rtadv no_radr" ipv6_static_routes="ovhgw" ipv6_route_ovhgw="2001:41d0:0001:c1ff:ff:ff:ff:ff -prefixlen 128 -interface ibg0" ipv6_defaultrouter="2001:41d0:0001:c1ff:ff:ff:ff:ff" mysql_enable="YES" root@rescue-bsd:~ # ``` 6\. Unmount ZFS partitions: ```bash root@rescue-bsd:~ # zfs unmount /tmp/rootClient/ root@rescue-bsd:~ # zfs get mountpoint zroot/ROOT/default NAME PROPERTY VALUE SOURCE zroot/ROOT/default mountpoint /tmp/rootClient local root@rescue-bsd:~ # zfs setuntpoint zroot/ROOT/default root@rescue-bsd:~ # zfs set mountpoint=/ zroot/ROOT/default root@rescue-bsd:~ # zfs get mountpoint zroot/ROOT/default NAME PROPERTY VALUE SOURCE zroot/ROOT/default mountpoint / local root@rescue-bsd:~ # zfs list -t all NAME USED AVAIL REFER MOUNTPOINT zroot 1.01G 673G 88K /zroot zroot/ROOT 1.00G 673G 88K none zroot/ROOT/default 1.00G 18.5G 1.00G / zroot/home 88K 673G 88K /home root@rescue-bsd:~ # zpool export zroot root@rescue-bsd:~ # zfs list -t all no datasets available root@rescue-bsd:~ # ``` [](#) ### Gentoo After a motherboard has been replaced, you cannot modify the new MAC addresses through the OS via rescue mode. 1\. Reboot the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) and locate the partition `/`: ```bash root@rescue:~# blkid /dev/sda1: UUID="15D6-5706" TYPE="vfat" PARTLABEL="grub" PARTUUID="bf514348-6259-41a4-a73f-ba0c38d45de5" /dev/sda2: UUID=`15D6-8A6F` TYPE=`vfat` PARTLABEL=`boot` PARTUUID=`7c0cbc80-c09a-4226-b7f2-91689a04250c` /dev/sda3: UUID=`Q1r3UN-wfmY-QSPI-jIvA-9ybX-IWwk-YNNnUg` TYPE=`LVM2_member` PARTLABEL=`lvm` PARTUUID=`79581bf9-3eb3-4947 9-c51-856fb5d72ffa` /dev/mapper/vg0-swap: UUID="337409d9-cdc5-4db8-a957-336631d3e7cb" TYPE="swap" /dev/mapper/vg0-root: UUID="2b672f12-77be-40c2-a099-487565ffa933" TYPE="xfs" root@rescue:~# ``` In our example, the system uses _LVM_: ```bash root@rescue:~# lvdisplay --- Logical volume --- LV Path /dev/vg0/swap LV Name swap VG Name vg0 LV UUID X9ttby-08vi-iJVW-aJGP-qnep-PDI9-ohJF6J LV Write Access read/write LV Creation host, time rescue.ovh.net, 2019-06-03 16:21:38 -0400 LV Status available # open 0 LV Size 128.00 GiB Current LE 32768 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 252:0 --- Logical volume --- LV Path /dev/vg0/root LV Name root VG Name vg0 LV UUID 822GLw-DELk-Q1ze-3NJD-1B3W-LT9H-CG8RTO LV Write Access read/write LV Creation host, time rescue.ovh.net, 2019-06-03 16:21:44 -0400 LV Status available # open 0 LV Size 17.34 TiB Current LE 4545078 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 252:1 ``` 2\. Mount the `/` identified partition: ```bash root@rescue:~# mount /dev/vg0/root /mnt root@rescue:~# ls /mnt backups bin boot dev etc home images images-ear images-ueba lib lib32 media mnt opt overlayimages proc root run sbin srv sys tmp uploads usr var ``` In Gentoo, MAC addresses are present in the following 4 files: ```bash root@rescue:~# cat /mnt/etc/systemd/network/ 10-external.link 11-internal.link 50-static.network 51-vrack.network root@rescue:~# ``` 3\. Back up files before editing them: ```bash root@rescue:~# cp /mnt/etc/systemd/network/50-static.network /mnt/etc/systemd/network/50-static.network.`date +%s` root@rescue:~# cp /mnt/etc/systemd/network/51-vrack.network /mnt/etc/systemd/network/51-vrack.network.`date +%s` root@rescue:~# cp /mnt/etc/systemd/network/10-external.link /mnt/etc/systemd/network/10-external.link.`date +%s` root@rescue:~# cp /mnt/etc/systemd/network/11-internal.link /mnt/etc/systemd/network/11-internal.link.`date +%s` ``` 4\. Update the files with the new MAC addresses: ```bash root@rescue:~# nano /mnt/etc/systemd/network/50-static.network root@rescue:~# nano /mnt/etc/systemd/network/51-vrack.network root@rescue:~# nano /mnt/etc/systemd/network/10-external.link root@rescue:~# nano /mnt/etc/systemd/network/11-internal.lin ``` 5\. Unmount the partitions, then _reboot_: ```bash root@rescue:~# umount /mnt root@rescue:~# reboot ``` #### Special cases For some versions, only the file ` /mnt/etc/udev/rules.d/10-f2c-network.rules` needs to be modified: ```bash root@rescue:~# cat /mnt/etc/gentoo-release Gentoo Base System release 2.2 root@rescue:~# root@rescue:~# ls /mnt/etc/udev/rules.d/ 10-f2c-network.rules root@rescue:~# root@rescue:~# cat /mnt/etc/udev/rules.d/10-f2c-network.rules SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", ATTR{type}=="1", KERNEL=="*", NAME="netpublic0" SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", ATTR{type}=="1", KERNEL=="*", NAME="netprivate0" root@rescue:~# ``` [](#) ### Proxmox/Debian (excluding Debian 12+) If you are experiencing network connectivity issues (for example, no ping after a motherboard replacement), this may be related to an error during system startup caused by the old MAC address value still present: ![proxmox](/images/bare-metal-cloud/dedicated-servers/intervention-support/proxmox_edited.jpg) Do the following: 1\. Reboot the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md). ```bash root@rescue:~# cat /mnt/etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback iface enp3s0f0 inet manual auto vmbr0 iface vmbr0 inet dhcp bridge-ports enp3s0f0 bridge-stp off bridge-fd 0 auto vmbr1 iface vmbr1 inet static address 192.168.22.254 netmask 255.255.255.0 bridge_ports none bridge_stp off bridge_fd 0 post-up echo 1 > /proc/sys/net/ipv4/ip_forward root@rescue:~# root@rescue:~# cat /mnt/var/log/messages | grep renamed Aug 8 14:27:20 s22 kernel: [ 1.527563] igb 0000:04:00.0 eno1: renamed from eth0 Aug 8 14:27:20 s22 kernel: [ 1.550622] igb 0000:04:00.1 eno2: renamed from eth1 Aug 8 14:27:34 s22 kernel: [ 88.148303] eth0: renamed from vethGRELEP Aug 8 14:27:36 s22 kernel: [ 90.444727] eth0: renamed from vethVMV0MH Aug 8 14:27:40 s22 kernel: [ 94.116739] eth0: renamed from vethQWYCXT Aug 8 14:27:43 s22 kernel: [ 97.469199] eth0: renamed from vethAIWWWX Aug 8 14:27:48 s22 kernel: [ 102.101324] eth0: renamed from vethB2DGCS Aug 8 14:27:48 s22 kernel: [ 102.139437] eth1: renamed from vethRSNNKL root@rescue:~# ``` 2\. Create the `70-persistent-net.rules` file again and add: - The network interface name found in the `/mnt/etc/network/interfaces` file. - The new MAC address (viewable in the tab Network interfaces in the OVHcloud Control Panel or in the return of the command `ip link`). ```bash root@rescue:~# cat /mnt/etc/udev/rules.d/70-persistent-net.rules SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", NAME="enp3s0f0" root@rescue:~# ``` [](#) ### XenServer If you are experiencing network connectivity issues (for example, no ping after a motherboard replacement), the MAC address is static configured and must be reset. Do the following: 1\. Restart the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) and use the `chroot` command: ```bash root@rescue:~# mount /dev/sda1 /mnt root@rescue:~# mount -t proc /proc/ /mnt/proc/ root@rescue:~# mount -o bind /sys/ /mnt/sys/ root@rescue:~# mount -o bind /dev/ /mnt/dev/ root@rescue:~# mount -o bind /dev/pts/ /mnt/dev/pts/ root@rescue:~# chroot /mnt ``` 2\. Change the current configuration to match the new settings: ```bash [root@rescue /]# xe-reset-networking --device=eth0 --mode=static --ip=xx.xx.xx.xx --netmask=255.255.255.0 --gateway=xx.xx.xx.xxx ``` 3\. You will be asked to answer the question with `yes`, then press Enter: ```bash ---------------------------------------------------------------------- !! WARNING !! This command will reboot the host and reset its network configuration. Any running VMs will be forcefully shutdown. Before completing this command: - Where possible, cleanly shutdown all VMs running on this host. - Disable HA if this host is part of a resource pool with HA enabled. ---------------------------------------------------------------------- Your network will be re-configured as follows: Management interface: eth0 IP configuration mode: static IP address: xx.xx.xx.xx Netmask: 255.255.255.0 Gateway: xx.xx.xx.xx Pool master's address: xx.xx.xx.xx If you want to change any of the above settings, type 'no' and re-run the command with appropriate arguments (use --help for a list of options). Type 'yes' to continue. Type 'no' to cancel. yes Stopping xapi... Reconfiguring eth0... Updating inventory file... Running in chroot, ignoring request. ``` 4\. Type "exit" to leave `chroot` mode, then unmount all partitions: ```bash root@rescue:~# umount /mnt/sys root@rescue:~# umount /mnt/proc root@rescue:~# umount /mnt/dev/pts root@rescue:~# umount /mnt/dev root@rescue:~# umount /mnt ``` #### Special cases You need to check and adapt the following files: - `/mnt/etc/sysconfig/network-scripts/interface-rename-data/static-rules.conf` - `/mnt/etc/sysconfig/network-scripts/interface-rename-data/dynamic-rules.json` [](#) ### ESXi After a motherboard has been replaced, you cannot modify the new MAC addresses through the `esxi.conf` file via the tools integrated in rescue mode. This will require manual intervention. #### Version 7.0 or newer The following procedure applies only to **versions 7.0 and later**. From this release on, the state.tgz file is encrypted. You will need to reboot the network from the Direct Console menu via your KVM or IPMI. Please refer to the screenshot below: ![reset_network](/images/bare-metal-cloud/dedicated-servers/intervention-support/restore.png) #### Version 6.7 or older The procedure described below applies only to **versions 6.7 and earlier**. 1\. Restart the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) to mount the partition `/`: ```bash root@rescue:~# mount /dev/sdaX /mnt/ ``` 2\. Save the `state.tgz file` ```bash root@rescue:~# ls /mnt/state.tgz root@rescue:~# cp /mnt/state.tgz /mnt/state.tgz.`date +%s` ``` 3\. Create a working environment: ```bash root@rescue:~# mkdir /home/ovh/esxi root@rescue:~# WORKINGDIR=/home/ovh/esxi root@rescue:~# cd $WORKINGDIR ``` 4. Extract the contents of `state.tgz` to `$WORKINGDIR` , and then extract the contents of `local.tgz` . 5. Edit the resulting `esx.conf` file: ```bash root@rescue:/home/ovh/esxi# tar xf /mnt/state.tgz -C $WORKINGDIR root@rescue:/home/ovh/esxi# tar xf /home/ovh/esxi/local.tgz -C $WORKINGDIR root@rescue:/home/ovh/esxi# vim etc/vmware/esx.conf ``` 6\. Locate and modify the MAC address for `vmkernelnic`: ```bash /net/vmkernelnic/child[0000]/mac = "XX:XX:XX:XX:XX:XX" ``` 7\. Identify on which interface the primary IP address is used: ```bash /net/vswitch/child[0000]/uplinks/child[0000]/pnic = "vmnicX" ``` 8\. Update the MAC address of the main interface: :::warning Do not change the virtual MAC address. ::: ```bash /net/pnic/child[0001]/mac = "XX:XX:XX:XX:XX:XX" <== Primary Interface Mac address /net/pnic/child[0001]/virtualMac = "00:50:56:XX:XX:XX" <== Virtual Mac /net/pnic/child[0001]/name = "vmnic1" ``` :::warning If there is a vRack interface, remember to also change its MAC address. ::: 9\. Perform a backup, then unmount the partition `/`: ```bash root@rescue:/home/ovh/esxi# tar -czf $WORKINGDIR/local.tgz etc/ root@rescue:/home/ovh/esxi# tar -czf /mnt/state.tgz local.tgz root@rescue:/home/ovh/esxi# umount /mnt ``` #### Special cases Check the order of your vmnicX declarations. Here is a functional example: ```bash root@rescue:/home/ovh/esxi# cat etc/vmware/esx.conf | grep "/vmkdevmgr/pci" /vmkdevmgr/pci/m00008901/alias = "vmhba0" /vmkdevmgr/pci/m00008501/alias = "vmnic0" /vmkdevmgr/pci/m00008502/alias = "vmnic1" ``` [](#) ### Windows (Hyper-V) After the motherboard is replaced, the server cannot be reached until you manually change the MAC addresses through **Device Manager**. There are 2 methods: #### Via IPMI/KVM 1. Log in as an administrator from the [IPMI/KVM](/it/guides/bare-metal-cloud/dedicated-servers/ipmi.md) interface. 2. Open the `Run ` utility (Windows logo key + `R `), and through the `run` prompt, run the `devmgmt.msc` command: ![win_device_manager](/images/bare-metal-cloud/dedicated-servers/intervention-support/win_device_manager_edited.png) 3. Open `Network adapters ` and select the adapter corresponding to `eth0` . 4. Right-click on `Properties ` > `Advanced `. 5. Locate `Locally Administered Address` . 6. Enter the new value for the MAC address (numbers only, no spaces). ![win_advanced](/images/bare-metal-cloud/dedicated-servers/intervention-support/win_advanced_edited.png) #### Via WinPE 1. Restart the server in `WinPE` mode. 2. Issue the `regedit` command at the `run` command prompt. 3. Load the local registry through the one available in `WinPE` , then click `HKEY_LOCAL_MACHINE `: ![win_regedit_1](/images/bare-metal-cloud/dedicated-servers/intervention-support/win_regedit_1_edited.png) 4. Then click `Load Hive... `. ![win_regedit_2](/images/bare-metal-cloud/dedicated-servers/intervention-support/win_regedit_2_edited.png) :::info By default, you will be in the WinPE tree. Don't forget to browse to `C:\`. ::: 5\. Locate the `SYSTEM` registry. ![win_load](/images/bare-metal-cloud/dedicated-servers/intervention-support/win_load_edited.png) 6\. You will be asked to enter a name. For example, you can choose `OVH_TEST`. 7\. Locate the following registry value: ```bash "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}" ``` :::warning As long as we are on WinPE, the value `CurrentControlSet` should be equal to `CurrentSet001`. ::: You should see several subkeys named like this: 0000, 0001, etc. 8\. Click each subkey to check the `DriverDesc` value that should match your network interface. You can check the name of your interface from a terminal using the following command: ```bash ipconfig /all ``` 9\. Look in the `NetworkAddress` registry entries on the right pane and change the value to your new MAC address. If this entry does not exist, right-click in an empty box to create a `String` with the name `NetworkAddress`. ![win_regedit_3](/images/bare-metal-cloud/dedicated-servers/intervention-support/win_regedit_3_edited.png) 10. You will need to unload the registry to apply the recent changes. Click OVH_TEST (created earlier) then click `File ` (in the top left-hand corner) and select `Unload hive... `. [](#) ### Locate the name of your network interfaces After the motherboard is replaced, the server cannot be reached because the network interface controller has been renamed by the operating system. 1\. Restart the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md), mount the partition `/` and then use the `chroot` command: ```bash root@rescue:~# mount /dev/my_disk /mnt root@rescue:~# for i in /dev /dev/pts /proc /sys; do mount -B $i /mnt$i; done root@rescue:~# chroot /mnt ``` 2\. Check if the interfaces have been modified. Check the `var/log/messages` logs or `var/log/kern.log` if the interface has been renamed: ```bash Oct 9 22:25:49 node1 kernel: [ 5.479916] ixgbe 0000:03:00.1 eno4: renamed from eth1 Oct 9 22:25:49 node1 kernel: [ 5.504285] ixgbe 0000:03:00.0 eno3: renamed from eth0 ``` 3\. Check your configuration file `/mnt/etc/udev/rules.d/70-persistent.-net.rules` and replace the new values (MAC addresses) if necessary: ```bash root@rescue:~# cat /mnt/etc/udev/rules.d/70-persistent-net.rules SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="public" SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="xx:xx:xx:xx:xx:xx", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="private" ``` 4. Go to the directory `/boot/grub/` and create a backup of the file `grub.cfg` . 5. Edit the `/etc/default/grub` file and edit the line beginning with `GRUB_CMDLINE_LINUX` to get this: ```bash GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0" ``` 6\. Run the command: ```bash root@rescue:~# grub-mkconfig -o /boot/grub/grub.cfg ``` 7\. Exit the `chroot` environment using the `exit` command and unmount all partitions: ```bash root@rescue:~# umount /mnt/sys root@rescue:~# umount /mnt/proc root@rescue:~# umount /mnt/dev/pts root@rescue:~# umount /mnt/dev root@rescue:~# umount /mnt ``` [](#) ### Problems with your EFI partition The following steps are indicated if you experience a boot problem related to the partitions present on your disks. There are 2 methods, via rescue mode or via BIOS. #### Via rescue mode - Use case: The installed system (in this case Proxmox) is no longer bootable after the disk has been replaced (no EFI input is visible through the BIOS). 1. Reboot the server in [rescue mode](/it/guides/bare-metal-cloud/dedicated-servers/rescue-mode.md) . 2. Locate the disk with the original EFI partition: ```bash Disk /dev/nvme1n1: 894.3 GiB, 960197124096 bytes, 1875385008 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/nvme0n1: 894.3 GiB, 960197124096 bytes, 1875385008 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: A28EAF07-248B-4CEB-86D4-92F75A36F1B0 Device Start End Sectors Size Type /dev/nvme0n1p1 34 1048609 1048576 512M EFI System /dev/nvme0n1p2 1050624 1875368589 1874317966 893.8G Solaris /usr & Apple ZFS /dev/nvme0n1p9 1875368590 1875384974 16385 8M Solaris reserved 1 ``` 3\. Mount the partition concerned. ```bash root@rescue:~# ls /mnt/EFI/proxmox/grubx64.efi /mnt/EFI/proxmox/grubx64.efi root@rescue:~# root@rescue:~# umount /mnt ``` 4\. Use the following command to make this partition functional again: ```bash root@rescue:~# efibootmgr -v --create --disk /dev/nvme0n1 --part 1 --label "proxmox2" --loader '\EFI\proxmox\grubx64.efi' BootCurrent: 0005 Timeout: 1 seconds BootOrder: 0000,0005,0007,0006,0008,0001 Boot0001* proxmox Vendor(99e275e7-75a0-4b37-a2e6-c5385e6c00cb,) Boot0005* UEFI: PXE IP4 P0 Intel(R) Ethernet Controller X550 ACPI(a0341d0,0)PCI(1b,4)PCI(0,0)MAC(MAC(d05099d5e395,1)..BO Boot0006 UEFI: PXE IP4 P1 Intel(R) Ethernet Controller X550 ACPI(a0341d0,0)PCI(1b,4)PCI(0,1)MAC(MAC(d05099d5e394,1)..BO Boot0007 UEFI: Built-in EFI Shell Vendor(5023b95c-db26-429b-a648-bd47664c8012,)..BO Boot0008* UEFI: PXE IP4 P0 American Megatrends Inc. ACPI(a0341d0,0)PCI(14,0)USB(7,0)USB(2,1)MAC(MAC(2ab925859a66,0)..BO Boot0000* proxmox2 HD(1,22,100000,0df658ff-5461-470a-9d92-5d95208d5c0f)File(\EFI\proxmox\grubx64.efi) ``` #### Via BIOS - Use case: the installed system (in this case CentOS 6) is no longer bootable after replacing the disk (no EFI input is visible through the BIOS). 1\. Reboot the server to enter the BIOS menu. The _first step_ involves regenerating the files you need to restore your partition to full operation: - Go to the BIOS `boot` menu: - Select Add New Boot Option. - Choose the path to your Path for boot partition option and select the file system that contains your boot partition. - Select the `EFI\centos6\bootx64.efi` file and choose Create. The image below is a summary of the actions mentioned above: The _second sequence_ is to make the selected partition active in the previous sequence. - In the BIOS `boot` menu: - Choose UEFI Hard Disk BBS Priorities. - Choose UEFI Boot Order #1 then select CENTOS6 to position it as the first start choice in the current list. The image below is a summary of the actions mentioned above: ## Go further [](#) Join our [community of users](https://community.ovhcloud.com/).