Fill up your disk and tell you when it's full

wrtr.go

package main

import (
        "crypto/rand"
        "encoding/hex"
        "fmt"
        "io"
        "os"
)

func uuid() string {
        id := make([]byte, 16)
        io.ReadFull(rand.Reader, id)
        id[6] &= 0x0F // clear version
        id[6] |= 0x40 // set version to 4 (random uuid)
        id[8] &= 0x3F // clear variant
        id[8] |= 0x80 // set to IETF variant
        return hex.EncodeToString(id)
}

func main() {
        oneKB := make([]byte, 1000)
        io.ReadFull(rand.Reader, oneKB)

        count := 0

        for {
                if count%1000 == 0 {
                        fmt.Printf("MB #%d\n", count/1000)
                }

                err := os.WriteFile(uuid(), oneKB, 0666)
                if err != nil {
                        fmt.Printf("Errored at count '%d': %s\n", count, err)
                        os.Exit(1)
                }

                count++
        }
}