Mount SDHC on sheevaplug
ページを編集するにはログインが必要です。
SDカードをマウントしてみる
SC08GADK2A1SHCM（BUFFALO）8GB SDHC CLASS6 をマウントしてみよう。
ざくっと挿して、まづは、パーテションを切って、フォーマット。
root@SheevaPlug:~# fdisk /dev/mmcblk0
:
Command (m for help): p
Disk /dev/mmcblk0: 8204 MB, 8204058624 bytes
108 heads, 6 sectors/track, 24727 cylinders
Units = cylinders of 648 * 512 = 331776 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 13 24728 8007680 b W95 FAT32
Command (m for help): d
Selected partition 1
Command (m for help): p
Disk /dev/mmcblk0: 8204 MB, 8204058624 bytes
108 heads, 6 sectors/track, 24727 cylinders
Units = cylinders of 648 * 512 = 331776 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-24727, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-24727, default 24727):
Using default value 24727
Command (m for help): p
Disk /dev/mmcblk0: 8204 MB, 8204058624 bytes
108 heads, 6 sectors/track, 24727 cylinders
Units = cylinders of 648 * 512 = 331776 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 1 24727 8011545 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
root@SheevaPlug:~# mkfs.ext2 /dev/mmcblk0p1
mke2fs 1.41.3 (12-Oct-2008)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
500960 inodes, 2002886 blocks
100144 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2051014656
62 block groups
32768 blocks per group, 32768 fragments per group
8080 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks):
done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 27 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override.
root@SheevaPlug:/home/nitobe#
お・遅い。異様に遅い。
次にファイルの読み書き。
root@SheevaPlug:/home/nitobe# mount /dev/mmcblk0p1 /mnt root@SheevaPlug:/home/nitobe# cd /mnt root@SheevaPlug:/mnt# df Filesystem 1K-blocks Used Available Use% Mounted on rootfs 519168 196776 322392 38% / tmpfs 257816 0 257816 0% /lib/init/rw varrun 257816 36 257780 1% /var/run varlock 257816 0 257816 0% /var/lock udev 257816 12 257804 1% /dev tmpfs 257816 0 257816 0% /dev/shm tmpfs 257816 0 257816 0% /var/cache/apt /dev/mmcblk0p1 7885736 148796 7336364 2% /mnt root@SheevaPlug:/mnt# root@SheevaPlug:/mnt# time dd if=/dev/zero of=/mnt/test bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB) copied, 53.1529 s, 2.5 MB/s real 1m1.068s user 0m0.010s sys 0m1.370s root@SheevaPlug:/mnt# time dd if=/mnt/test of=/dev/null bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB) copied, 0.592085 s, 227 MB/s real 0m0.603s user 0m0.010s sys 0m0.590s
Write:2.5MB/s 遅い。異様に遅い。
現在、2.6.22.18 のカーネルを、2.6.30-rXにアップデートすると改善するらしい。
2.6.30-r8で再計測
仕切り直しだ。パーテイショニングとフォーマットは省略。
内臓 NAND Flash
root@SheevaPlug:~# time dd if=/dev/zero of=/mnt/test bs=64k count=2k
2048+0 records in
2048+0 records out
134217728 bytes (134 MB) copied, 21.024 s, 6.4 MB/s
real 0m21.142s
user 0m0.020s
sys 0m19.600s
root@SheevaPlug:~# time dd if=/mnt/test of=/dev/null bs=64k count=2k
2048+0 records in
2048+0 records out
134217728 bytes (134 MB) copied, 0.597294 s, 225 MB/s
real 0m0.610s
user 0m0.010s
sys 0m0.600s
root@SheevaPlug:~# time rm /mnt/test
real 0m0.109s
user 0m0.010s
sys 0m0.100s
仕切り直しだ。パーテイショニングとフォーマットは省略。
内臓 NAND Flash
root@SheevaPlug:~# time dd if=/dev/zero of=/mnt/test bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 21.024 s, 6.4 MB/s real 0m21.142s user 0m0.020s sys 0m19.600s root@SheevaPlug:~# time dd if=/mnt/test of=/dev/null bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 0.597294 s, 225 MB/s real 0m0.610s user 0m0.010s sys 0m0.600s root@SheevaPlug:~# time rm /mnt/test real 0m0.109s user 0m0.010s sys 0m0.100s
外付け SD カード
SC08GADK2A1SHCM（BUFFALO）8GB SDHC CLASS6
root@SheevaPlug:~# dmesg : mmc0: host does not support reading read-only switch. assuming write-enable. mmc0: new high speed SDHC card at address 0002 mmcblk0: mmc0:0002 SD 7.64 GiB mmcblk0: p1 root@SheevaPlug:~# mount /dev/mmcblk0p1 /mnt root@SheevaPlug:~# time dd if=/dev/zero of=/mnt/test bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 12.4273 s, 10.8 MB/s real 0m12.441s user 0m0.000s sys 0m1.760s root@SheevaPlug:~# time dd if=/mnt/test of=/dev/null bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 0.571348 s, 235 MB/s real 0m0.584s user 0m0.010s sys 0m0.580s root@SheevaPlug:~# time rm /mnt/test real 0m0.601s user 0m0.000s sys 0m0.140s root@SheevaPlug:~# umount /mnt
外付け USB Flash
RUF2-SWT2G-PAR (BUFFALO) 綾波レイ|http://buffalo.jp/products/catalog/flash/swattears/ruf2-swt-par/
root@SheevaPlug:~# dmesg : usb 1-1: new high speed USB device using orion-ehci and address 2 usb 1-1: configuration #1 chosen from 1 choice scsi0 : SCSI emulation for USB Mass Storage devices usb-storage: device found at 2 usb-storage: waiting for device to settle before scanning scsi 0:0:0:0: Direct-Access BUFFALO USB Memory 4000 PQ: 0 ANSI: 0 CCS sd 0:0:0:0: Attached scsi generic sg0 type 0 usb-storage: device scan complete sd 0:0:0:0: [sda] 3915776 512-byte hardware sectors: (2.00 GB/1.86 GiB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Mode Sense: 23 00 00 00 sd 0:0:0:0: [sda] Assuming drive cache: write through sd 0:0:0:0: [sda] Assuming drive cache: write through sda: sda1 sd 0:0:0:0: [sda] Attached SCSI removable disk root@SheevaPlug:~# mount /dev/sda1 /mnt root@SheevaPlug:~# time dd if=/dev/zero of=/mnt/test bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 4.63065 s, 29.0 MB/s real 0m4.643s user 0m0.000s sys 0m1.470s root@SheevaPlug:~# time dd if=/mnt/test of=/dev/null bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 0.587955 s, 228 MB/s real 0m0.600s user 0m0.000s sys 0m0.600s root@SheevaPlug:~# time rm /mnt/test real 0m0.328s user 0m0.000s sys 0m0.320s root@SheevaPlug:~# umount /mnt
外付け USB-HDD
HD-PF160U2-BK(BUFFALO)
root@SheevaPlug:~# dmesg : usb 1-1: new high speed USB device using orion-ehci and address 3 usb 1-1: configuration #1 chosen from 1 choice scsi1 : SCSI emulation for USB Mass Storage devices usb-storage: device found at 3 usb-storage: waiting for device to settle before scanning scsi 1:0:0:0: Direct-Access WDC WD16 00BEVT-22ZCT0 PQ: 0 ANSI: 2 sd 1:0:0:0: Attached scsi generic sg0 type 0 usb-storage: device scan complete sd 1:0:0:0: [sda] 312581808 512-byte hardware sectors: (160 GB/149 GiB) sd 1:0:0:0: [sda] Write Protect is off sd 1:0:0:0: [sda] Mode Sense: 38 00 00 00 sd 1:0:0:0: [sda] Assuming drive cache: write through sd 1:0:0:0: [sda] Assuming drive cache: write through sda: sda1 sd 1:0:0:0: [sda] Attached SCSI disk root@SheevaPlug:~# mount /dev/sda1 /mnt root@SheevaPlug:~# time dd if=/dev/zero of=/mnt/test bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 2.82488 s, 47.5 MB/s real 0m2.882s user 0m0.000s sys 0m1.710s root@SheevaPlug:~# time dd if=/mnt/test of=/dev/null bs=64k count=2k 2048+0 records in 2048+0 records out 134217728 bytes (134 MB) copied, 0.561543 s, 239 MB/s real 0m0.574s user 0m0.010s sys 0m0.560s root@SheevaPlug:~# time rm /mnt/test real 0m0.147s user 0m0.000s sys 0m0.140s root@SheevaPlug:~# umount /mnt
| Kernel | Media | Write | Read | |
| 2.6.30-r8 | 内臓NAND Flash | 6.4 MB/s | 225 MB/s | 64k*2k |
| 2.6.22.18 | 外付SD | 2.5 MB/s | 227 MB/s | 1M*128 |
| 2.6.30-r8 | 外付SD | 10.8 MB/s | 235 MB/s | 64k*2k |
| 2.6.30-r8 | 外付USB Flash | 29.0 MB/s | 228 MBs | 64k*2k |
| 2.6.30-r8 | 外付USB HDD | 47.5 MB/s | 239 MB/s | 64k*2k |
綾波レイが予想外に速い。 本来、数回実行して平均を求めるところだが、ざっくりわかればいいので、一発勝負だ。あくまで、傾向・・・ってことで。神経質な方は自分で計測してください。
Keyword(s):
References: