# Hardware > Nodes, specs, disks, network, VIP, domain ... --- -------- ## Node Pigsty currently runs on nodes with [`Linux`](#linux-os) kernel and `x86_64` / `aarch64` architecture. A "**node**" refers to a resource that is SSH [accessible](#accessibility) and offers a bare Linux OS environment. It could be a physical machine, a virtual machine, or an OS-like container equipped with `systemd`, `sudo` and `sshd`. It requires at least 1 node to deploy pigsty, You can prepare more and setup everything in [one-pass](/docs/admin/playbook#deployment), or add them later. The minimum node spec requirement is `1C1G`, it is recommended to use at least `2C2G`. Higher is better, with no upper limit. Parameters will be automatically tuned based on available resource. **Use multiple nodes for production deployment** A functioning HA setup requires at least **3** nodes to work, or use **2** for a semi-HA setup -------- ## Spec How many nodes do you need? It depends on your resource and your requirements. **Single Node Setup** The simplest setup with everything running on a single node, with four essential modules installed: | ID | [NODE](/docs/node) | [PGSQL](/docs/pgsql) | [INFRA](/docs/infra) | [**ETCD**](/docs/etcd) | |:--:|:------------------:|:--------------------:|:--------------------:|:----------------------:| | 1 | `node-1` | `pg-meta-1` | `infra-1` | `etcd-1` | This setup can be used for production if external S3/MinIO is configured for backup/PITR. **Two Node Setup** A two-node setup enables database replication and semi-HA capabilities: | ID | [NODE](/docs/node) | [PGSQL](/docs/pgsql) | [INFRA](/docs/infra) | [**ETCD**](/docs/etcd) | |:--:|:------------------:|:---------------------:|:--------------------:|:----------------------:| | 1 | `node-1` | `pg-meta-1` (primary) | `infra-1` | `etcd-1` | | 2 | `node-2` | `pg-meta-2` (replica) | | | While more robust than a single node setup, HA has limitations: - No automatic failover if `node-1` fails - manual promotion of `node-2` required - Automatic failover works if `node-2` fails - `node-1` gets promoted automatically This "semi-HA" setup can only auto-recover from specific node failures. **Three Node Setup** A true HA setup that can automatically recover from any single node failure: | ID | [NODE](/docs/node) | [PGSQL](/docs/pgsql) | [INFRA](/docs/infra) | [**ETCD**](/docs/etcd) | |:--:|:------------------:|:--------------------:|:--------------------:|:----------------------:| | 1 | `node-1` | `pg-meta-1` | `infra-1` | `etcd-1` | | 2 | `node-2` | `pg-meta-2` | `infra-2` | `etcd-2` | | 3 | `node-3` | `pg-meta-3` | `infra-3` | `etcd-3` | **Four Node Setup** The standard demonstration environment used by Pigsty's [sandbox](/docs/prepare/sandbox): | ID | [NODE](/docs/node) | [PGSQL](/docs/pgsql) | [INFRA](/docs/infra) | [**ETCD**](/docs/etcd) | |:--:|:------------------:|:--------------------:|:--------------------:|:----------------------:| | 1 | `node-1` | `pg-meta-1` | `infra-1` | `etcd-1` | | 2 | `node-2` | `pg-test-1` | | `etcd-2` | | 3 | `node-3` | `pg-test-2` | | `etcd-3` | | 4 | `node-4` | `pg-test-3` | | | ------ ## Disk Pigsty will use `/data` as the default data directory, if you have a dedicated main data disk, it is recommended to mount it there, and use `/data1`, `/data2`, `/dataN` for extra disk drivers. **Mount disks elsewhere?** If you are mounting it elsewhere, you'll have to change the following parameters accordingly: | Name | Description | Default | |--------------------------------------------------------|--------------------------------|--------------------| | [`node_data`](/docs/node/param#node_data) | node main data directory | `/data` | | [`pg_fs_main`](/docs/pgsql/param#pg_fs_main) | postgres main data directory | `/data` | | [`pg_fs_backup`](/docs/pgsql/param#pg_fs_backup) | postgres backup data directory | `/data/backups` | | [`etcd_data`](/docs/etcd/param#etcd_data) | etcd data directory | `/data/etcd` | | [`prometheus_data`](/docs/infra/param#prometheus_data) | prometheus data directory | `/data/prometheus` | | [`loki_data`](/docs/infra/param#loki_data) | loki data directory | `/data/loki` | | [`minio_data`](/docs/minio/param#minio_data) | minio data directory | `/data/minio` | | [`redis_fs_main`](/docs/redis/param#redis_fs_main) | redis data directory | `/data/redis` | We recommend using `ext4` or `xfs` as the filesystem for data disks. They have the best performance for PostgreSQL. While `ext4` has more tools for data recovery, `xfs` is more efficient for small files. If you are running MinIO, It's recommended to use `xfs`, otherwise, `ext4` is recommended as the default option. -------- ## Network Pigsty requires **static network** to work, you should explicitly assign a **fixed** IPv4 address for each node. **Don't have a fixed IP?** The `127.0.0.1` could be used as a workaround in case of no fixed IP address in one-node installation. The IP address will be used as the node's **unique identifier**, it should be the primary IP address bind to the primary network interface used for **internal** network communications. **Never use Public IP as identifier** Using public IP addresses as node identifiers can cause security and connectivity issues. **L2 VIP require L2 Networking** To use the optional Node VIP and PG VIP features, ensure all nodes are located within the same L2 network Internet access is required when performing the standard (online) [**installation**](/docs/install). But pigsty can be [offline installed](/docs/install/offline) via offline package, which does not require Internet access in this case. -------- ## VIP Pigsty supports optional L2 VIP for NODE clusters (`keepalived`) and PGSQL clusters (`vip-manager`). To use L2 VIP features, You have to explicitly assign an L2 VIP for them. It's not a big deal when running on your own hardware, but may become an issue when working in a public cloud environment. -------- ## Domain Pigsty using local static domain names for the following service with WebUI. You can assign your custom domain names to these services, or use real domain names. Just change them in the [`infra_portal`](/docs/infra/param#infra_portal). | Domain | Name | Port | Component | Description | |:----------:|----------------|:----------:|:--------------------------------------------------:|-----------------------------| | `h.pigsty` | `home` | **80/443** | [**Nginx**](/docs/infra/arch/#nginx) | Default server, local repo | | `g.pigsty` | `grafana` | **3000** | [**Grafana**](/docs/infra/arch/#grafana) | Monitoring & visualization | | `p.pigsty` | `prometheus` | 9058 | [**Prometheus**](/docs/infra/arch/#prometheus) | Time series DB | | `a.pigsty` | `alertmanager` | 9059 | [**AlertManager**](/docs/infra/arch/#alertmanager) | Alert aggregation & routing | Domain names are optional, to use them, it is user's responsibility to add the following records to your `/etc/hosts` file (local static resolution), Or add them to your DNS server / public DNS vendor. ```bash 10.10.10.10 h.pigsty g.pigsty p.pigsty a.pigsty ```