windows:

C:\Documents and Settings\Administrator>fsutil fsinfo ntfsinfo c:
NTFS Volume Serial Number :       0x343439fc3439c1a2
Version :                         3.1
Number Sectors :                  0x0000000002711675
Total Clusters :                  0x00000000004e22ce
Free Clusters  :                  0x000000000032031c
Total Reserved :                  0x00000000000001f0
Bytes Per Sector  :               512
Bytes Per Cluster :               4096 --OS block size
Bytes Per FileRecord Segment    : 1024
Clusters Per FileRecord Segment : 0
Mft Valid Data Length :           0x0000000002914000
Mft Start Lcn  :                  0x00000000000c0000
Mft2 Start Lcn :                  0x0000000000000010
Mft Zone Start :                  0x00000000000c2900
Mft Zone End   :                  0x000000000015c460

UNIX:

-bash-3.00$ df -g |grep 'block size'
/                  (/dev/dsk/c0t2d0s0 ):         8192 block size          1024 frag size
/devices           (/devices          ):          512 block size           512 frag size
/system/contract   (ctfs              ):          512 block size           512 frag size
/proc              (proc              ):          512 block size           512 frag size
/etc/mnttab        (mnttab            ):          512 block size           512 frag size
/etc/svc/volatile  (swap              ):         4096 block size          4096 frag size
/system/object     (objfs             ):          512 block size           512 frag size
/lib/libc.so.1     (/usr/lib/libc/libc_hwcap2.so.1):     8192 block size          1024 frag size
/dev/fd            (fd                ):         1024 block size          1024 frag size
/tmp               (/dev/dsk/c0t2d0s3 ):         8192 block size          1024 frag size
/var/run           (swap              ):         4096 block size          4096 frag size
/unixcenter/home   (/dev/dsk/c0t3d0s7 ):         8192 block size          1024 frag size
/export/home       (/dev/dsk/c0t2d0s7 ):         8192 block size          1024 frag size
/home              (192.168.2.5:/store/home):     8192 block size           512 frag size