From df device name to physical drive name (vendor / type)

sudo lshw -class disk
  *-cdrom                 
       description: DVD-RAM writer
       product: CDDVDW SH-S223Q
       vendor: TSSTcorp
       physical id: 0
       bus info: scsi@0:0.0.0
       logical name: /dev/cdrom
       logical name: /dev/cdrw
       logical name: /dev/dvd
       logical name: /dev/dvdrw
       logical name: /dev/sr0
       version: SB02
       capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram
       configuration: ansiversion=5 status=ready
     *-medium
          physical id: 0
          logical name: /dev/cdrom
  *-disk
       description: ATA Disk
       product: WDC WD1600AAJS-0
       vendor: Western Digital
       physical id: 1
       bus info: scsi@1:0.0.0
       logical name: /dev/sda
       version: 01.0
       serial: WD-WMAV2P964464
       size: 149GiB (160GB)
       capabilities: partitioned partitioned:dos
       configuration: ansiversion=5 signature=000c0805
  *-disk
       description: SCSI Disk
       physical id: 0.0.0
       bus info: scsi@6:0.0.0
       logical name: /dev/sdb
       size: 931GiB (1TB)
       capabilities: partitioned partitioned:dos
       configuration: signature=a39eabc7

The QNAP NAS products run firmware that is essentially a custom Linux distro. It is quite spartan, with a minimal set of command line tools (and many of those provided by busybox). Fortunately, there is a decent implementation of hdparm in there, so you should be able to query a drive, as follows:

hdparm -I /dev/sda

Here's the output I get from a "QNAP TS-239 Pro NAS" with a "Western Digital RE4 1TB" drive (output is verbatim, except for the drive's serial number, which I have purposely obscured):

/dev/sda:

ATA device, with non-removable media
    Model Number:       WDC WD1003FBYX-01Y7B0                   
    Serial Number:      AB-CDEF01234567
    Firmware Revision:  01.01V01
Standards:
    Supported: 8 7 6 5 
    Likely used: 8
Configuration:
    Logical     max current
    cylinders   16383   16383
    heads       16  16
    sectors/track   63  63
    --
    CHS current addressable sectors:   16514064
    LBA    user addressable sectors:  268435455
    LBA48  user addressable sectors: 1953525168
    device size with M = 1024*1024:      953869 MBytes
    device size with M = 1000*1000:     1000204 MBytes (1000 GB)
Capabilities:
    LBA, IORDY(can be disabled)
    Queue depth: 32
    Standby timer values: spec'd by Standard, with device specific minimum
    R/W multiple sector transfer: Max = 16  Current = 0
    Advanced power management level: unknown setting (0x0080)
    Recommended acoustic management value: 128, current value: 254
    DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 
         Cycle time: min=120ns recommended=120ns
    PIO: pio0 pio1 pio2 pio3 pio4 
         Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
    Enabled Supported:
       *    NOP cmd
       *    READ BUFFER cmd
       *    WRITE BUFFER cmd
       *    Host Protected Area feature set
       *    Look-ahead
       *    Write cache
       *    Power Management feature set
            Security Mode feature set
       *    SMART feature set
       *    FLUSH CACHE EXT command
       *    Mandatory FLUSH CACHE command 
       *    Device Configuration Overlay feature set 
       *    48-bit Address feature set 
       *    Automatic Acoustic Management feature set 
            SET MAX security extension
       *    SET FEATURES subcommand required to spinup after power up
            Power-Up In Standby feature set
       *    Advanced Power Management feature set
       *    DOWNLOAD MICROCODE cmd
       *    General Purpose Logging feature set
       *    SMART self-test 
       *    SMART error logging 
Security: 
    Master password revision code = 65534
        supported
    not enabled
    not locked
    not frozen
    not expired: security count
        supported: enhanced erase
    168min for SECURITY ERASE UNIT. 168min for ENHANCED SECURITY ERASE UNIT.
Checksum: correct

"Vendor" and "Type" are not explicitly reported by hdparm. However, "Model Number" is reported, and a quick web search on it should yield anything you need to know about a drive.

Most modern Linux systems use udev to manage devices. This isn't the case on all embedded devices though; I don't know whether this specific device uses udev.

udevadm info -n /dev/sda3 -a
udevadm info -n /dev/sda3 -q property

will print everything the system knows about /dev/sda3. This is the same info you'll find in /sys, but udev does the work of walking down the hierarchy to collect all the data.