SD卡读写速度实在是太慢了，不堪用，决定更新硬件，从固态硬盘启动树莓派。一方面提升性能，一方面延长寿命。
SD卡速度测试
笔者的树莓派使用SanDisk 64GB micro SD卡。
使用如下指令测试SD卡写入性能(oflag=direct选项将跳过内存缓存直接读写)。
$ time dd if=/dev/zero of=test bs=8k count=10000 oflag=direct
10000+0 records in
10000+0 records out
81920000 bytes (82 MB, 78 MiB) copied, 20.9216 s, 3.9 MB/s
real 0m20.927s
user 0m0.039s
sys 0m0.904s
这速度不予置评。测试读取性能。
$ time dd if=test of=/dev/null bs=8k count=10000 iflag=direct
10000+0 records in
10000+0 records out
81920000 bytes (82 MB, 78 MiB) copied, 4.81443 s, 17.0 MB/s
real 0m4.819s
user 0m0.043s
sys 0m0.289s
测完会生成一个test文件，记得删除。
硬件更新
使用的m.2转USB拓展板型号X862 V2.0，硬盘选用Kingston A400 m.2 2280 SATA接口SSD。
另外之前购买的风扇又坏了，因为选择的液压轴承不能承受全天候工作的强度。所以也更换了滚珠轴承的新风扇。
由于笔者仍然需要铝合金的散热外壳，而官方提供的螺丝配件不能满足要求，所以另外购买了铜柱、尼龙垫片和螺栓重新组装；为了更好的散热还给SSD加装了硅脂贴片。
固态硬盘速度测试
创建分区并格式化
安装完成后开机，查看用fdisk工具磁盘设备。
$ sudo fdisk -l
... ...
Disk /dev/mmcblk0: 59.48 GiB, 63864569856 bytes, 124735488 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x44cc6dad
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 532479 524288 256M c W95 FAT32 (LBA)
/dev/mmcblk0p2 532480 124735487 124203008 59.2G 83 Linux
Disk /dev/sda: 447.13 GiB, 480103981056 bytes, 937703088 sectors
Disk model: 2115
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 33553920 bytes
注意到设备/dev/mmcblk0就是SD卡，目前系统仍然运行在这上面；设备/dev/sda就是新安装的固态硬盘。
用fdisk工具建立分区并格式化硬盘。
$ sudo fdisk /dev/sda
Welcome to fdisk (util-linux 2.36.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xfb2bec60.
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p):
Using default response p.
Partition number (1-4, default 1):
First sector (65535-937703087, default 65535):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (65535-937703087, default 937703087):
Created a new partition 1 of type 'Linux' and of size 447.1 GiB.
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
使用指令sudo fdisk /dev/sda将打开一个ui，n是创建新分区，w是保存分区设置并退出。具体帮助可以用m打开。
使用指令mkfs格式化分区，笔者这里将硬盘格式化为ext4文件系统。
$ sudo mkfs -t ext4 /dev/sda1
mke2fs 1.46.2 (28-Feb-2021)
Creating filesystem with 117204694 4k blocks and 29302784 inodes
Filesystem UUID: 0a859952-4dd9-4553-ad71-44e4537f5e42
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000
Allocating group tables: done
Writing inode tables: done
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done
再次查看分区情况。
$ sudo fdisk -l /dev/sda
Disk /dev/sda: 447.13 GiB, 480103981056 bytes, 937703088 sectors
Disk model: 2115
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 33553920 bytes
Disklabel type: dos
Disk identifier: 0xfb2bec60
Device Boot Start End Sectors Size Id Type
/dev/sda1 65535 937703087 937637553 447.1G 83 Linux
挂载
查看已格式化分区。
$ sudo parted -l
Model: ASMT 2115 (scsi)
Disk /dev/sda: 480GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 33.6MB 480GB 480GB primary ext4
Model: SD SN64G (sd/mmc)
Disk /dev/mmcblk0: 63.9GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 4194kB 273MB 268MB primary fat32 lba
2 273MB 63.9GB 63.6GB primary ext4
挂载并修改权限。
mkdir ssd
sudo mount -t ext4 /dev/sda1 /home/pi/ssd/
sudo chown -R pi:pi /home/pi/ssd
注意：ext4文件系统不支持在挂载时设置权限，需要在挂载后手动设置。
查看磁盘和挂载情况。
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 59G 12G 44G 22% /
devtmpfs 1.7G 0 1.7G 0% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 759M 2.4M 757M 1% /run
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
/dev/mmcblk0p1 253M 53M 201M 21% /boot
tmpfs 380M 4.0K 380M 1% /run/user/1000
/dev/sda1 440G 28K 417G 1% /home/pi/ssd
读写测试
写入性能。
$ time dd if=/dev/zero of=ssd/test bs=8k count=10000 oflag=direct
10000+0 records in
10000+0 records out
81920000 bytes (82 MB, 78 MiB) copied, 1.88336 s, 43.5 MB/s
real 0m1.887s
user 0m0.040s
sys 0m0.709s
芜湖起飞。读取性能。
$ time dd if=ssd/test of=/dev/null bs=8k count=10000 iflag=direct
10000+0 records in
10000+0 records out
81920000 bytes (82 MB, 78 MiB) copied, 1.56033 s, 52.5 MB/s
real 0m1.565s
user 0m0.026s
sys 0m0.429s
💥完爆SD卡。
系统拷贝
旧的系统需要拷贝到固态硬盘上。使用工具rpi-clone，安装教程参考作者的repo。
$ sudo rpi-clone sda
Booted disk: mmcblk0 63.9GB Destination disk: sda 480.1GB
---------------------------------------------------------------------------
Part Size FS Label Part Size FS Label
1 /boot 256.0M fat32 -- 1 447.1G ext4 --
2 root 59.2G ext4 rootfs
---------------------------------------------------------------------------
== Initialize: IMAGE partition table - partition number mismatch: 2 -> 1 ==
1 /boot (52.0M used) : MKFS SYNC to sda1
2 root (12.0G used) : RESIZE MKFS SYNC to sda2
---------------------------------------------------------------------------
Run setup script : no.
Verbose mode : no.
-----------------------:
** WARNING ** : All destination disk sda data will be overwritten!
-----------------------:
Initialize and clone to the destination disk sda? (yes/no): yes
Optional destination ext type file system label (16 chars max):
Initializing
Imaging past partition 1 start.
=> dd if=/dev/mmcblk0 of=/dev/sda bs=1M count=8 ...
Resizing destination disk last partition ...
Resize success.
Changing destination Disk ID ...
=> mkfs -t vfat -F 32 /dev/sda1 ...
=> mkfs -t ext4 /dev/sda2 ...
Syncing file systems (can take a long time)
Syncing mounted partitions:
Mounting /dev/sda2 on /mnt/clone
=> rsync // /mnt/clone with-root-excludes ...
Mounting /dev/sda1 on /mnt/clone/boot
=> rsync /boot/ /mnt/clone/boot ...
Editing /mnt/clone/boot/cmdline.txt PARTUUID to use a678da9c
Editing /mnt/clone/etc/fstab PARTUUID to use a678da9c
===============================
Done with clone to /dev/sda
Start - 19:35:36 End - 19:43:37 Elapsed Time - 8:01
Cloned partitions are mounted on /mnt/clone for inspection or customizing.
Hit Enter when ready to unmount the /dev/sda partitions ...
unmounting /mnt/clone/boot
unmounting /mnt/clone
===============================
完成后关机拔掉SD卡即可，再次启动就是SSD了。
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 439G 12G 405G 3% /
devtmpfs 1.7G 0 1.7G 0% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 759M 992K 758M 1% /run
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
/dev/sda1 253M 53M 201M 21% /boot
tmpfs 380M 4.0K 380M 1% /run/user/1000
$ sudo fdisk -l /dev/sda
Disk /dev/sda: 447.13 GiB, 480103981056 bytes, 937703088 sectors
Disk model: 2115
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 33553920 bytes
Disklabel type: dos
Disk identifier: 0xa678da9c
Device Boot Start End Sectors Size Id Type
/dev/sda1 8192 532479 524288 256M c W95 FAT32 (LBA)
/dev/sda2 532480 937703087 937170608 446.9G 83 Linux
参考
mount时发生错误:wrong fs type, bad option, bad superblock on
Unrecognized mount option “uid=33” or missing value