Delete record in Aerospike?

I'm tuning Aerospike, after I use Recipe for an SSD Storage Engine with this config:

namespace test {
        replication-factor 2
        memory-size 4G
        default-ttl 30d # 30 days, use 0 to never expire/evict.

        #storage-engine memory
        storage-engine device {     # Configure the storage-engine to use persistence
        device /dev/vdb    # raw device. Maximum size is 2 TiB
        # device /dev/  # (optional) another raw device.
        write-block-size 128K   # adjust block size to make it efficient for SSDs.
    }
}

After run the benchmarks first time,my SSD is completely full

quanlm@quanlm2:/mnt/device$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            2.0G     0  2.0G   0% /dev
tmpfs           395M  3.1M  392M   1% /run
/dev/vda1        60G  2.8G   54G   5% /
tmpfs           2.0G     0  2.0G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           2.0G     0  2.0G   0% /sys/fs/cgroup
/dev/vdb         64Z   64Z   59G 100% /mnt/device
tmpfs           395M     0  395M   0% /run/user/1000

So is there anyway to delete the data in my SSD (/dev/vdb) ?