我有三星 NVMe SSD 960EVO 250GB 磁盘，当使用 hdparm -tT 测试读取速度时，它给出了一些奇怪的结果。
修剪前速度
/dev/nvme0n1:
Timing cached reads: 24486 MB in 2.00 seconds = 12256.70 MB/sec
Timing buffered disk reads: 5502 MB in 3.00 seconds = 1832.95 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p1
/dev/nvme0n1p1:
Timing cached reads: 24878 MB in 2.00 seconds = 12452.22 MB/sec
Timing buffered disk reads: 190 MB in 0.09 seconds = 2151.12 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p2
/dev/nvme0n1p2:
Timing cached reads: 24270 MB in 2.00 seconds = 12147.96 MB/sec
Timing buffered disk reads: 5308 MB in 3.00 seconds = 1769.32 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p3
/dev/nvme0n1p3:
Timing cached reads: 22976 MB in 2.00 seconds = 11499.27 MB/sec
Timing buffered disk reads: 7140 MB in 3.00 seconds = 2379.80 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p4
/dev/nvme0n1p4:
Timing cached reads: 23908 MB in 2.00 seconds = 11967.15 MB/sec
Timing buffered disk reads: 7022 MB in 3.00 seconds = 2339.82 MB/sec
修剪后速度
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1
/dev/nvme0n1:
Timing cached reads: 25168 MB in 2.00 seconds = 12597.67 MB/sec
Timing buffered disk reads: 5548 MB in 3.00 seconds = 1848.97 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p1
/dev/nvme0n1p1:
Timing cached reads: 25226 MB in 2.00 seconds = 12627.85 MB/sec
Timing buffered disk reads: 190 MB in 0.09 seconds = 2177.97 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p2
/dev/nvme0n1p2:
Timing cached reads: 24356 MB in 2.00 seconds = 12191.47 MB/sec
Timing buffered disk reads: 5424 MB in 3.00 seconds = 1807.88 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p3
/dev/nvme0n1p3:
Timing cached reads: 24770 MB in 2.00 seconds = 12398.57 MB/sec
Timing buffered disk reads: 7590 MB in 3.00 seconds = 2529.50 MB/sec
jkalmar@supercomp:~> sudo hdparm -tT /dev/nvme0n1p4
/dev/nvme0n1p4:
Timing cached reads: 24532 MB in 2.00 seconds = 12279.30 MB/sec
Timing buffered disk reads: 6960 MB in 3.00 seconds = 2319.36 MB/sec
可以看到，除了最后一个分区速度较慢外，trim 都起到了一定作用，但速度还是相当不错的。第二个分区的速度不太好。
安装选项：
/dev/nvme0n1p1 on /boot/efi type vfat (rw,relatime,fmask=0002,dmask=0002,allow_utime=0020,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
/dev/nvme0n1p2 on / type ext4 (rw,relatime,data=ordered)
/dev/nvme0n1p3 on /home type ext4 (rw,relatime,data=ordered)
/dev/nvme0n1p4 on /zaloha type ext4 (rw,relatime,data=ordered)
DF-H
Filesystem Size Used Avail Use% Mounted on
/dev/nvme0n1p2 23G 8,1G 14G 38% /
/dev/nvme0n1p1 188M 4,6M 183M 3% /boot/efi
/dev/nvme0n1p3 110G 27G 82G 25% /home
/dev/nvme0n1p4 82G 16G 65G 20% /zaloha
智能数据
=== START OF SMART DATA SECTION ===
SMART/Health Information (NVMe Log 0x02, NSID 0xffffffff)
Critical Warning: 0x00
Temperature: 34 Celsius
Available Spare: 100%
Available Spare Threshold: 10%
Percentage Used: 0%
Data Units Read: 1 168 294 [598 GB]
Data Units Written: 470 952 [241 GB]
Host Read Commands: 6 529 515
Host Write Commands: 4 815 912
Controller Busy Time: 22
Power Cycles: 63
Power On Hours: 59
Unsafe Shutdowns: 9
Media and Data Integrity Errors: 0
Error Information Log Entries: 0
Warning Comp. Temperature Time: 0
Critical Comp. Temperature Time: 0
Temperature Sensor 1: 34 Celsius
Temperature Sensor 2: 35 Celsius
根据智能数据可以看出该驱动器相当新。
分开
(parted) print
Model: NVMe Device (nvme)
Disk /dev/nvme0n1: 488397168s
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 2048s 391167s 389120s fat32 boot, esp
2 391168s 49219583s 48828416s ext4
3 49219584s 283594751s 234375168s ext4
4 283594752s 457674751s 174080000s ext4
(parted) align-check optimal 1
1 aligned
(parted) align-check optimal 2
2 aligned
(parted) align-check optimal 3
3 aligned
(parted) align-check optimal 4
4 aligned
一切看起来都很好，但是分区 2 的速度比其他分区慢得多。有人知道原因吗？如果可以修复，如何修复？