可以用Smartontools查看Mac的磁盘信息，下面使用port安装此工具。
$ sudo port install smartmontools
查看SSD磁盘寿命情况，一般查看的是'Wear_Leveling_Count'，初始值应该是200，当这个值接近100时，就要考虑更换硬盘了。普通SSD在写入100T后是将逐渐会出现问题。
$ smartctl -a /dev/disk0
smartctl 6.4 2015-06-04 r4109 [x86_64-apple-darwin15.3.0] (local build)
Copyright (C) 2002-15, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Apple SD/SM/TS...E/F SSDs
Device Model: APPLE SSD SM256E
Serial Number: S0X5NYBC737708
LU WWN Device Id: 5 002538 043584d30
Firmware Version: CXM09A1Q
User Capacity: 251,000,193,024 bytes [251 GB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: Solid State Device
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4c
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Mon Aug 29 11:05:08 2016 CST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x02) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Disabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 960) seconds.
Offline data collection
capabilities: (0x5b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
No Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: ( 16) minutes.
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x001a 200 200 000 Old_age Always - 0
5 Reallocated_Sector_Ct 0x0033 100 100 000 Pre-fail Always - 0
9 Power_On_Hours 0x0032 099 099 000 Old_age Always - 4547
12 Power_Cycle_Count 0x0032 094 094 000 Old_age Always - 5464
169 Unknown_Attribute 0x0013 253 253 010 Pre-fail Always - 1873134229760
173 Wear_Leveling_Count 0x0032 190 190 100 Old_age Always - 90214170749
192 Power-Off_Retract_Count 0x0012 099 099 000 Old_age Always - 3873
194 Temperature_Celsius 0x0022 057 027 000 Old_age Always - 43 (Min/Max 9/73)
197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always - 0
199 UDMA_CRC_Error_Count 0x001a 200 200 000 Old_age Always - 0
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
No self-tests have been logged. [To run self-tests, use: smartctl -t]
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.