Debian SSD ext4 4 K alignment

Debian SSD ext4 4 K alignment

A new thinkpad was launched. The original hard drive was GB, So I purchased a micron MX200 GB SSD to install debian stable (jessie)

1. Press F1 before installing the system to enter the bios and change the mode to AHCI.
2. BOOT disk made of a USB flash disk. The version is debian 8.1 AMD64.
3. Select the default recommended partition when installing the system, that is, the entire partition.
4. debian8 is the ext4 File System by default.
5. After installation, fdisk-lu found that it was 4 K aligned.

Root @ debian:/home/tommy # fdisk-lu

Disk/dev/sda: 232.9 GiB, 250059350016 bytes, 488397168 sectors
Units: sectors of 1*512 = 512 bytes
Sector size (logical/physical): 512 bytes/4096 bytes
I/O size (minimum/optimal): 4096 bytes/4096 bytes
Disklabel type: dos
Disk identifier: 0xa6c609e3

Device Boot Start End Sectors Size Id Type
/Dev/sda1*2048 499711 497664 243 M 83 Linux
/Dev/sda2 501758 488396799 487895042 232.7G 5 Extended
/Dev/sda5 501760 488396799 487895040 232.7G 8e Linux LVM
Disk/dev/mapper/debian -- vg-root: 223.2 GiB, 239649947648 bytes, 468066304 sectors
Units: sectors of 1*512 = 512 bytes
Sector size (logical/physical): 512 bytes/4096 bytes
I/O size (minimum/optimal): 4096 bytes/4096 bytes
Disk/dev/mapper/debian -- vg-swap_1: 9.5 GiB, 10150215680 bytes, 19824640 sectors
Units: sectors of 1*512 = 512 bytes
Sector size (logical/physical): 512 bytes/4096 bytes
I/O size (minimum/optimal): 4096 bytes/4096 bytes
The original kernel> = 2.6.3 and later ext4 can be directly supported.

Write under test

# Dd if =/dev/zero of =./largefile bs = 1 M count = 1024
1024 + 0 records in
1024 + 0 records out
1073741824 bytes (1.1 GB) copied, 0.800335 s, 1.3 GB/s

# Sh-c "sync & echo 3>/proc/sys/vm/drop_caches"

# Dd if =./largefile of =/dev/null bs = 4 k
262144 + 0 records in
262144 + 0 records out
1073741824 bytes (1.1 GB) copied, 4.68755 s, 229 MB/s
The write speed is 1.3 GB/s. The read speed is consistent with the access speed of sata2.

This article permanently updates the link address: