Volume filesystem not resized to match block device (ext4 only 434MB on 37.3GB block device)

Question

### Environment

* **Service:** PostgreSQL 18.1 (Debian 18.1-1.pgdg12+2)
* **Volume ID:**`vol_qtkfr9mwjxjkrkl3`
* **Configured Volume Size:** 40.00 GB
* **Region:** (see dashboard)

## Problem Summary

The Railway volume is configured to 40GB, but the ext4 filesystem inside the volume was never expanded to fill the underlying block device.

As a result, PostgreSQL is reporting:

```
No space left on device
```

even though the volume appears to have sufficient capacity.

##

### Filesystem Size (df -h)

```
Filesystem      Size  Used Avail Use% Mounted on
/dev/zd12208    434M  413M   12M  98% /var/lib/postgresql
```

The ext4 filesystem is only **434MB**, nearly full.

### Block Device Size (lsblk)

```
zd12208 230:12208  0  37.3G  0 disk /var/lib/postgresql
```

The underlying block device is actually **37.3GB**, confirming that:

* The block device was expanded
* The ext4 filesystem was **not** resized to match

### Mount Information

```
/dev/zd12208 on /var/lib/postgresql type ext4 (rw,relatime,discard,stripe=8192)
```

Impact

* PostgreSQL is stuck in a crash loop
* WAL recovery requires writes but fails due to no space
* The database is currently down
* Recovery cannot be performed from inside the container

## PostgreSQL Crash Log

```
2026-03-02 20:01:43.211 UTC [28] LOG:  database system was interrupted while in recovery at 2026-03-02 20:01:36 UTC
2026-03-02 20:01:48.806 UTC [28] FATAL:  could not write to file "pg_wal/xlogtemp.28": No space left on device
2026-03-02 20:01:48.816 UTC [2] LOG:  shutting down due to startup process failure
```

Attempted Resolution

Running `resize2fs` inside the container fails because:

* The block device node does not exist in `/dev`
* `mknod` is not permitted due to container restrictions
* The container does not have sufficient privileges to resize the filesystem

Requested Fix

Please run the following from the **host level**:

```
resize2fs /dev/zd12208
```

Device details:

* Device name: `zd12208`
* Major:Minor: `230:12208`
* Expected size after resize: \~37.3GB

Once the ext4 filesystem is expanded to match the full block device size, PostgreSQL should be able to complete WAL recovery and start normally.