This page documents the Quintex PoP.

[[TOC]]

Tutorial

How-to

Out of band access

OOB access happens over the dal-rescue-01 host, a APU server hooked up to the main switch (dal-sw-01) and a special OOB management switch that interconnects all the other OOB interfaces. You can find the OOB IP address(es) of each host in the corresponding oob/ entry in the password store.

The host can be accessed over SSH normally by TPA members. From there, there are various ways of accessing the other hosts' management interfaces.

SSH jump host

The simplest way to access a server is by using dal-rescue-01 as a jump host and connecting to the management interface over SSH. For example, this will connect to the management interface on dal-node-01:

ssh -J dal-rescue-01.torproject.org ADMIN@172.30.141.101 -o HostKeyAlgorithms=+ssh-rsa -oMACs=+hmac-sha2-256

Note the -o HostKeyAlgorithms=+ssh-rsa -oMACs=+hmac-sha2-256, required for clients running later OpenSSH versions that have those algorithms disabled.

HTTP over SSH (port forwarding)

The SSH management interface is limited and undocumented, it's better to connect to the web interface as this also provides a graphical console. For this, you can use port forwarding:

ssh -L 8043:172.30.141.101:443 dal-rescue-01.torproject.org

The URL to connect to the management interface, in this case, would be https://localhost:8043/.

SSH SOCKS proxy

You can also use OpenSSH's SOCKS proxy support:

ssh -D9092 dal-rescue-01.torproject.org

And point your web browser to the SOCKS proxy on localhost:9092 to connect to the remote host with (say) https://172.30.141.101/. You can have a conditional proxy configuration in Firefox by creating a PAC file, for example:

function FindProxyForURL(url, host) {
  if (isInNet(host, "172.30.141.0", "255.255.255.0")) {
    return "PROXY localhost:9092";
  }
  return "DIRECT";
}

Save that file in a known location (say ~/.mozilla/tpa-gnt-dal-proxy.pac). That file can be fed in the "Automatic proxy configuration URL" with by setting that field to (say) file:///home/anarcat/.mozilla/tpa-gnt-dal-proxy.pac.

sshuttle VPN

Finally, sshuttle can also act as a proxy or ad-hoc VPN in a similar way:

sshuttle -r dal-rescue-01.torproject.org 172.30.141.0/24

... but requires more privileges.

Remote console

The Supermicro firmware offers a web and Serial Over IPMI consoles on the servers.

Web console

To open the web ("HTML5") console, simply open the IP address in your browser, compare the self-signed certificate fingerprint with the one stored in the password database (only needed upon first access) and login to the BMC.

Once inside, click the console screenshot image to bring up the a new browser window containing the interactive web console.

If the browser offers you a .jnlp instead, you need to configure the BMC to offer the HTML5 console instead of the Java-based version. To do so, navigate to Remote control -> Remote console, click here where it shows To set the Remote Console default interface, please click. here and select HTML5.

IPMI console

The other option is the IPMI or "Serial Over LAN" (SOL) console. That provides an easier console for technical users as things like copy-paste actually work correctly. That needs to be setup in the BIOS however, so if everything goes south, the web console might be a better option, even if only to power-cycle the machine to rescue it from a freeze.

To access the SOL console, you first need the ipmitool package:

sudo apt install ipmitool

Then the following command will give you a serial console on 192.168.200.1:

ipmitool -I lanplus -H 192.168.200.1 -U $USERNAME sol activate

That should prompt for a password. That password and the $USERNAME should be available in the tor-passwords.git repository, in hosts-extra-info. The lanplus argument tells ipmitool the remote server is compatible with the IPMI v2.0 RMCP+ LAN Interface, see also the Intel specification for IPMI v2.

The ipmitool(1) manual page has more information, but some quick tips:

~. will end the session
~B sends a break (so presumably you can send a magic sysrq key to reset a CPU that way)
~? shows other supported commands

Note that the escape sequence is recognized only after a newline, as in SSH.

BIOS setup

To access the BIOS, press Del during the boot process.

When a machine is provisioned, a few BIOS settings need to be adjusted:

go to Save & Exit and select Restore Optimized Defaults
Advanced -> Boot Feature -> Quiet Boot set to Disabled
Advanced -> Boot Feature -> Power Button Function set to 4 second override
Advanced -> PCIe/PCI/PnP Configuration -> NVME2/3 SATA0-7 set to SATA
go to Save & Exit and select Save Changes and Reset

Alternatives

Supermicro offers a multi-platform utility that provides the ability to export/import BIOS configuration: Supermicro Update Manager

Since we don't have very many Supermicro nodes to manage at this point, the benefit isn't considered the trouble of deploying it.

Network boot

Machines at the Quintex PoP should be able to boot off the network in the "storage" VLAN. The boot is configured in a TFTP server that's offered by the DHCP server, so as long as a PXE-enabled network card is correctly connected on the VLAN, it should be able to boot over the network.

At the time of writing (this might change!) the interface layout in the iPXE environment is like this:

net0: management LAN
net1: public network
not detected: extra Intel gigabit network

First, connect to the OOB management interface (see above).

Then you need to somehow arrange the machine to boot from the network. On some Supermicro servers, this consists of pressing F11 to bring up the boot menu and selecting the UEFI: ATEN Virtual Floppy 3000 entry at the Please select the boot device: menu.

The boot offers a menu with a couple of options, the first option should overwhelmingly be the right one, unless there is a pressing need to use serial consoles. The menu is configured in Puppet, in the autoexec.ipxe.epp template, and should look like:

 GRML boot
 GRML boot with ttyS0 serial console
 GRML boot with ttyS1 serial console
 GRML fromiso= boot (legacy)
 Drop to iPXE shell
 Reboot computer
 Configure settings
 Retry getting a DHCP lease
 Exit iPXE and continue BIOS boot

It might take a while (a minute?) to load the GRML image into memory. There should be a percentage that slowly goes up.

Some iPXE troubleshooting tricks

You can get into a iPXE shell by frantically hitting control-b while it loads, or by selecting Drop to iPXE shell in the menu.

You will see ok when the initialization completes and then the following prompt:

iPXE 1.21.1+ (g4e456) -- Open Source Network Boot Firmware -- https://ipxe.org
Features: DNS HTTP HTTPS iSCSI TFTP VLAN SRP AoE EFI Menu
iPXE>

At the prompt, configure the network, for example:

set net0/ip 204.8.99.99
set net0/netmask 255.255.255.0
set net0/gateway 204.8.99.254

The net0 is hooked to the public VLAN, so this will make the machine publicly visible, and able to access the public network.

Typically, however, it's better to configure only the internal network (storage VLAN), which is typically on the net1 interface:

set net1/ip 172.30.131.99
set net1/netmask 255.255.255.0
set net1/gateway 172.30.131.1

You might need to enable an interface before it works with:

ifopen net0

You can check the open/closed status of the interfaces with:

ifstat

And the IP configuration with:

route

Set a DNS server:

set dns 1.1.1.1

Make sure that iPXE can ping and resolve hosts on the Internet:

ping one.one

control c to stop.

If you ended up in the iPXE shell from the menu, you can return to the menu by typing exit, but if you have entered the shell directly without loading the menu, you can load it with:

chain http://172.30.131.1/autoexec.ipxe

If iPXE encounters a problem it will show you an error code which you can load in a web browser. For example, error code 3e1162 is available at https://ipxe.org/err/3e1162 and is "Error: No DNS servers available". That was caused by a missing DNS server (fix: set dns 1.1.1.1).

The transfer can also hang mysteriously. If a few minutes pass at the same percentage, you will need to do a power cycle on the machine and try again, see this bug report for a possible source of this problem.

GRML network setup

Once the image is loaded, you should do a "quick network configuration" in the grml menu (n key, or type grml-network in a shell). This will fire up a dialog interface to enter the server's IP address, netmask, gateway, and DNS. The first three should be allocated from DNS (in the 99.8.204.in-addr.arpa file of the dns/domains.git repository). The latter should be set to some public nameserver for now (e.g. Google's 8.8.8.8).

Alternatively, you can use this one-liner to set IP address, DNS servers and start SSH with your SSH key in root's list:

PUBLIC_KEY="ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKozLxDafID8L7eV804vNDho3pAmpvc43nYhXAXeH7wH openpgp:0xD101630D" &&
address=204.8.99.114 &&
prefix=24 &&
gateway=204.8.99.254 &&
interface=eno1 &&
echo nameserver 8.8.8.8 >> /etc/resolv.conf &&
ip link set dev $interface up &&
ip addr add dev $interface $address/$prefix &&
ip route add default via $gateway &&
mkdir -p /root/.ssh/ &&
echo "$PUBLIC_KEY" >> /root/.ssh/authorized_keys &&
service ssh restart

If you have booted with a serial console (which you should have), you should also be able to extract the SSH public keys at this point, with:

cat /etc/ssh/ssh_host_*.pub | sed "s/^/$address /"

This can be copy-pasted into your ~/.ssh/known_hosts file, or, to be compatible with the installer script below, you should instead use:

for key in /etc/ssh/ssh_host_*_key; do
    ssh-keygen -E md5 -l -f $key
    ssh-keygen -l -f $key
done

Phew! Now you have a shell you can use to bootstrap your installer.

Automated install procedure

To install a new machine in this PoP, you first need to:

connect to the Out of band access network
connect to the Remote console
boot the rescure system from the network
configure the network

From there on, the machine can be bootstrapped with a basic Debian installer with the howto/Fabric code in the fabric-tasks git repository. Here's an example of a commandline:

fab -H root@204.8.99.103 \
    install.hetzner-robot \
    --fqdn=dal-node-03.torproject.org \
    --console-idx=1 \
    --ipv4-address 204.8.99.103 \
    --ipv4-subnet 24 \
    --ipv4-gateway 204.8.99.254 \
    --fai-disk-config=installer/disk-config/gnt-dal-NVMe \
    --package-list=installer/packages \
    --post-scripts-dir=installer/post-scripts/

TODO: It also doesn't setup the canonical vg_ganeti group that further steps in the installer expect.

If the install fails, you can retry after remounting:

cd / ; \
for fs in boot/efi boot dev proc run/udev run sys/firmware/efi/efivars sys ; do
    umount /target/$fs
done &&
umount /target ; \
umount /target ; \
vgchange -a n ; \
(
    cd /dev/mapper ; \
    for cryptdev in crypt* ; do
        cryptsetup luksClose $cryptdev
    done
)
mdadm --stop /dev/md*

TODO: stop copy-pasting that shit and make that into a fabric job already.

See howto/new-machine for post-install configuration steps, then follow howto/new-machine-mandos for setting up the mandos client on this host.

Upstream routing issue

If there's a routing issue with Quintex, contact the support numbers documented in hosts-extra-info in tor-passwords.git.

Cold reboots and power management

The following commands assume you first opened a shell with:

ipmitool -I lanplus -H $HOST -U $USERNAME shell

show the power state of the device:
```
power status
```

example of a working server:

    Chassis Power is on

equivalent of a control-alt-delete:
```
power reset
```
cold reboot (power off and power on)
```
power cycle
```
show the error log:
```
sel list
```
show sensors:
```
sdr list
```

See also the IBM documentation on common IPMI commands.

Disaster recovery

TODO: disaster recovery plan for the Quintex PoP

If one machine becomes unbootable or unreachable, first try the out of band access. If the machine that failed is the OOB jump host (currently dal-rescue-01), a replacement box need to be shipped. One currently (2023-05-16) sits in @anarcat's office (dal-rescue-02) and should be able to act as a spare, with minimal testing beforehand.

If not, a new spare needs to be built, see howto/apu.

Reverse DNS

Reverse DNS is configured by modifying zone files in dns/domains.git (see tpo/tpa/repos> for info on how to access that repository).

Reference

Installation

Installing a new machine at Quintex should be done by following those steps:

connect to the Out of band access network
connect to the Remote console
boot a rescue system (currently GRML) with the modified iPXE image
automated install procedure

Upgrades

TODO: document how to do firmware upgrades on the switch, the machines.

SLA

Quintex provides us with a 45min SLA (source).

Design and architecture

The Quintex PoP is at the Infomart, a gigantic datacenter in Dallas, Texas. We have our own switch there donated by Quintex, a D-Link DGS-1250-52X switch. The servers are connected through the different VLANs on that switch. The OOB management network is on a separate "dumb" switch.

Network topology

This is the planned network topology, not fully implemented yet.

network topology graph

This network is split in those VLANs:

"public": VLAN 82 - 204.8.99.0/24, directly accessible on the global network, behind a Quintex router, eth0 on all nodes, could eventually be aggregated with eth2
"storage": VLAN 801 - 172.30.131.0/24, used by the Ganeti cluster for DRBD replication, not accessible by the internet, eth1 on all nodes, could eventually be aggregated with eth3
"OOB": VLAN 802 - 172.30.141.0/24, access to the "out of band" (OOB) management interfaces, not accessible by the internet, connected to the OOB or "IPMI" interface on all nodes, except on the dal-rescue-01 host, where it is eth2

Note that the above use the non-"predictable" interface names, i.e. eth0 and eth1 instead of eno1np0 and eno1np1 or enp129s0f0 and enp129s0f1.

Also note that have the public and storage VLANs on the same NIC (i.e. public on eth0 and storage on eth1). This is because we plan on doing aggregation in the long term and that will allow us to survive a NIC failure. Assuming NIC one has eth0 and eth1 and NIC two has eth2 and eth3, if the public VLAN is on eth0 and eth2, it will survive a failure of one NIC.

It physically looks like this:

Photo of the top of a 42U cabinet with three servers and a switch Details of the switch and servers, each server has 10 disk trays in front Back of the setup, where we see the extra management switch

The above pictures don't show the actual running switch, which has been replaced since those pictures were taken.

The machines are connected to a Dell N3048 switch that has 48 gigabit ports and two SFP ports. The SFP ports are 10gbit uplinks to the Quintex switch fabric.

Each machine's interfaces are connected to the switch in order, from left to right, of their interface ports, excluding the IPMI port. So, assuming the ports are numbered in order, the ports are actually mapped like this:

Switch  <----------> Server
Port  1 <----------> dal-node-01, port 1 (eth0)
Port  2 <----------> dal-node-01, port 2 (eth1)
Port  3 <----------> dal-node-01, port 3 (eth2)
Port  4 <----------> dal-node-01, port 4 (eth3)

Port  5 <----------> dal-node-02, port 1 (eth0)
Port  6 <----------> dal-node-02, port 2 (eth1)
Port  7 <----------> dal-node-02, port 3 (eth2)
Port  8 <----------> dal-node-02, port 4 (eth3)

Port  9 <----------> dal-node-03, port 1 (eth0)
Port 10 <----------> dal-node-03, port 2 (eth1)
Port 11 <----------> dal-node-03, port 3 (eth2)
Port 12 <----------> dal-node-03, port 4 (eth3)

The ports were manually mapped to the right VLANs through the switch web interface. There's an issue open to make sure we have some backups and better configuration management on the switch, see tpo/tpa/team#41089.

Services

The main service at this point of presence is a 3-machine Ganeti cluster called gnt-dal.

gnt-dal Hardware

Each machine is identical:

SuperMicro 1114CS-TNR 1U
AMD Milan (EPYC) 7713P 64C/128T @ 2.00Ghz 256M cache
512G DDR4 RAM (8x64G)
2x Micron 7450 PRO, 480GB PCIe 4.0 NVMe*, M.2 SSD
6x Intel S4510 1.92T SATA3 SSD
2x Intel DC P4610 1.60T NVMe SSD
Subtotal: 12,950$USD
Spares:
Micron 7450 PRO, 480GB PCIe 4.0 NVMe*, M.2 SSD: 135$
Intel® S4510, 1.92TB, 6Gb/s 2.5" SATA3 SSD(TLC), 1DWPD: 345$
Intel® P4610, 1.6TB NVMe* 2.5" SSD(TLC), 3DWPD: 455$
DIMM (64GB): 275$
labour: 55$/server
Total: 40,225$USD
TODO: final cost to be confirmed
Extras: shipping, 350$ (estimate)
Grand total: 41,000$USD (estimate)

For three such servers, we have:

192 cores, 384 threads
1536GB RAM (1.5TB)
34.56TB SSD storage (17TB after RAID-1)
9.6TB NVMe storage (4.8TB after RAID-1)

See TPA-RFC-43 for a more in-depth discussion of the chosen hardware and location.

Storage

Data in this cluster is stored on SSD and NVMe drive and should be fast. We have about 20TB of storage total, not counting DRBD redundancy.

Queues

Interfaces

Authentication

Implementation

Issues

There is no issue tracker specifically for this project, File or search for issues in the team issue tracker with the label ~Foo.

Maintainer

Users

Upstream

Monitoring and metrics

Tests

Logs

Backups

RANCID

The rancid package is installed on dal-rescue-01, and configured to download the running-config and other interesting bits from dal-sw-01 on a daily basis and store them in a git repository at /var/lib/rancid/dal/configs.

This is managed using the profile::rancid Puppet class.

Other documentation

Discussion

Overview

Security and risk assessment

Technical debt and next steps

Proposed Solution

A battery of proposals were made when migrating to Quintex, see:

Other alternatives

We are not fully satisfied with this hosting, see this comment for details.

Legacy iPXE configuration

We were previously using a custom iPXE image to boot off HTTPS in the network boot rescue environment. This is not required anymore as we boot over the local network in plain HTTP, but notes about how this was configured are kept here in case we need them again in the future.

We needed a special virtual host with a minimal certificate chain for iPXE to load it correctly. The certificate should be created with:

certbot --preferred-chain "ISRG Root X1" [...]

In our Dehydrated configuration, concretely, it meant adding an override in per-domain-config/dal-rescue.torproject.org with:

PREFERRED_CHAIN="ISRG Root X1"

Another workaround is to embed the certs in the iPXE trust chain.

This has been configured in the https://dal-rescue.torproject.org/ site already.

Note that we usually want the "full" variant. The "small" variant can also work but you'll have to adjust the path inside the mounted image from where vmlinux and initrd.img are extracted and also the live-media-path in the .ipxe file below.

On dal-rescue-01, download the GRML ISO and verify its signature:

IMAGE_NAME="grml-full-2025.08-amd64.iso"
apt install debian-keyring &&
cd /srv/www/dal-rescue.torproject.org/htdocs/ &&
wget "https://download.grml.org/${IMAGE_NAME}.asc" &&
wget "https://download.grml.org/${IMAGE_NAME}" &&
gpg --verify --keyring /usr/share/keyrings/debian-keyring.gpg "${IMAGE_NAME}.asc"

The last command above should identify a good signature from someone (for example Michael Prokop). It might not be able to verify a trust relationship to that key but at least identifying a good signature from a debian dev should be good enough.

Extract the vmlinuz and initrd.img boot files, and modify the latter as follows:

echo extracting vmlinuz and initrd from ISO... &&
mount "${IMAGE_NAME}" /mnt -o loop &&
cp /mnt/boot/grmlfullamd64/* . &&
umount /mnt &&
rm grml.iso && ln "${IMAGE_NAME}" grml.iso

In the above procedure, the files vmlinuz, initrd.img and grml.iso were placed in a directory that is currently exposed on a public HTTPS endpoint.

Note: we now loop-mount the ISO instead of doing this extraction.

If that fails at the first step on a torproject.org server, it's likely because the kernel cannot load the loop module:

mount: /mnt: mount failed: Operation not permitted.

Reboot and try again before the kernel lockdown happens. Alternatively, try to add loop, isofs and cdrom to /etc/modules.

If it does not already exist, create the file /srv/tftp/autoload.ipxe with the following contents:

#!ipxe

kernel https://dal-rescue.torproject.org/vmlinuz
initrd https://dal-rescue.torproject.org/initrd.img
initrd https://dal-rescue.torproject.org/grml.iso /grml.iso
imgargs vmlinuz initrd=initrd.magic boot=live config fromiso=/grml.iso live-media-path=/live/grml-full-amd64 noprompt noquick noswap console=tty0 console=ttyS1,115200n8 ssh netconfig=http://172.30.131.1/ssh-keys.tgz
boot

Note: we now deploy a more elaborate file from Puppet directly. We also load the .squashfs file instead of the ISO, which delegates the loading to the GRML init system instead of TFTP, so it has a better progress bar, and seems faster.

Modified iPXE image

To be able to load images over HTTPS, we had to rebuild iPXE with DOWNLOAD_PROTO_HTTPS and UEFI support:

git clone git://git.ipxe.org/ipxe.git &&
cd ipxe/src &&
mkdir config/local/tpa/ &&
cat > config/local/tpa/general.h <<EOF
#define DOWNLOAD_PROTO_HTTPS    /* Secure Hypertext Transfer Protocol */
#undef  NET_PROTO_STP       /* Spanning Tree protocol */
#undef  NET_PROTO_LACP      /* Link Aggregation control protocol */
#undef  NET_PROTO_EAPOL     /* EAP over LAN protocol */
#undef  CRYPTO_80211_WEP    /* WEP encryption (deprecated and insecure!) */
#undef  CRYPTO_80211_WPA    /* WPA Personal, authenticating with passphrase */
#undef  CRYPTO_80211_WPA2   /* Add support for stronger WPA cryptography */
#define NSLOOKUP_CMD        /* DNS resolving command */
#define TIME_CMD        /* Time commands */
#define REBOOT_CMD      /* Reboot command */
#define POWEROFF_CMD        /* Power off command */
#define PING_CMD        /* Ping command */
#define IPSTAT_CMD      /* IP statistics commands */
#define NTP_CMD     /* NTP commands */
#define CERT_CMD        /* Certificate management commands */
EOF
make -j4 bin-x86_64-efi/ipxe.efi CONFIG=tpa &&
dd if=/dev/zero of=./ipxe.img bs=512 count=2880 &&
sudo losetup loop0 ./ipxe.img &&
sudo mkfs.msdos /dev/loop0 &&
sudo mount /dev/loop0 /mnt &&
sudo mkdir -p /mnt/EFI/BOOT &&
sudo cp bin-x86_64-efi/ipxe.efi /mnt/EFI/BOOT/BOOTX64.EFI &&
sudo umount /mnt &&
sudo losetup -d /dev/loop0

Here we use named configurations instead of patching the global.h file. To be verified.

If we need to do this again, we might be able to rely on UEFI HTTP boot support and bypass iPXE altogether. Such a setup might be able to boot the ISO directly, from http://172.30.131.1/grml-full-2025.08-amd64.iso.

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