Painful speed for copying to fat32 partitions with small cluster size.

[Ion-Mihai Tetcu]

Hi,


Does anyone know why this happens or what to do ?


Setup: UDMA133 primary master, UFS2; UDMA100 secondary master, FAT32.

Copying to FAT32 partitions is very slow with small cluster sizes (I was
copying some 300 - 700MB files):

FAT32 clustersize=4K	500KB/s
FAT32 clustersize=32K	3.5MB/s
FAT32 clustersize=64K	6.2MB/s
FAT32 clustersize=128K	6.4MB/s
FAT16			6.5MB/s

Reading speed is the same.


Same experience for newfs_msdos: on a 10G partition:

itetcu at it> /home/itetcu [16:23:40] 0
# newfs_msdos -F32 -b32768  /dev/ad2s2
/dev/ad2s2: 20959616 sectors in 327494 FAT32 clusters (32768 bytes/cluster)
bps=512 spc=64 res=32 nft=2 mid=0xf0 spt=63 hds=16 hid=0 bsec=20964825 bspf=2559 rdcl=2 infs=1 bkbs=2
itetcu at it> /home/itetcu [16:24:51] 0
#
itetcu at it> /home/itetcu [16:28:56] 1
# newfs_msdos -F32 -b65536 /dev/ad2s2
/dev/ad2s2: 20962176 sectors in 163767 FAT32 clusters (65536 bytes/cluster)
bps=512 spc=128 res=32 nft=2 mid=0xf0 spt=63 hds=16 hid=0 bsec=20964825 bspf=1280 rdcl=2 infs=1 bkbs=2
itetcu at it> /home/itetcu [16:29:23] 0
#

Newfs_msdos on a 30G partition:

itetcu at it> /home/itetcu [16:31:40] 1
# newfs_msdos -F32 -b65536 /dev/ad2s1
/dev/ad2s1: 167746176 sectors in 1310517 FAT32 clusters (65536 bytes/cluster)
bps=512 spc=128 res=32 nft=2 mid=0xf0 spt=63 hds=16 hid=0 bsec=167766732 bspf=10239 rdcl=2 infs=1 bkbs=2
itetcu at it> /home/itetcu [16:34:48] 0
#

The same with 4K clusters takes about 50 minutes !


-- 
IOnut
Unregistered ;) FreeBSD user