Server and Operating System
- Kernel – vm.swappiness
Disables swapping completely while 1 causes the kernel to perform the minimum amount of swapping
# Set the swappiness value as root
echo 1 > /proc/sys/vm/swappiness
# Alternatively, using sysctl
sysctl -w vm.swappiness=1
# Verify the change
cat /proc/sys/vm/swappiness
1
# Alternatively, using sysctl
sysctl vm.swappiness
vm.swappiness = 1
Filesystems – XFS/ext4/ZFS
| FILE SIZE | mount option | |
|---|---|---|
| EXT4 | 16TB | noatime,data=writeback,barrier=0,nobh,errors=remount-ro |
| XFS | 8EiB | defaults,nobarrier |
Disk Subsystem – I/O scheduler
Most modern Linux distributions come with noop or deadline I/O schedulers by default, both providing better performance than the cfq and anticipatory ones
# View the I/O scheduler setting. The value in square brackets shows the running scheduler
cat /sys/block/sdb/queue/scheduler
noop deadline [cfq]
# Change the setting
sudo echo noop > /sys/block/sdb/queue/scheduler
Disk Subsystem – Volume optimization
separation of OS and data partitions, not just logically but physically, will improve database performance. The RAID level can also have an impact: RAID-5 should be avoided as the checksum needed to ensure integrity is costly
System Architecture – NUMA settings
the innodb_numa_interleave option to be available, MySQL must be compiled on a NUMA-enabled Linux system