MacBook SSD Replacement

とりあえずMacBookの充電関係が修理できたので起動時間が遅いのと，何かしらアプリケーションの立ち上がりが遅いのが気になりだした。HDDからSSDに交換するととても早くなるようなことが，散見されていたので自分でも試してみたくなった。

sequenceDiagram MacBook->>+HDD160GB: 取り出し HDD160GB->>-MacBook:　外付けドライブに入れる SSD120GB->>MacBook:HDDと交換する USBメディア->>MacBook:MacOSインストール HDD160GB->>MacBook:データの移行

iPodのSDXCに使っているせいもあってサムスン製品の信頼度は高い。程度の良さそうな(?)Samsung EVO 850の120GBを入手して，MacBookの純正と交換する。この形式のMacBookはバッテリー交換やHDD交換のメンテナンスがやりやすく，ラッチを上げるとHDDにアクセスできるのでビスをゆるめてHDDを取り外しSSDと入れ替えする。 MacOSが認識できないファイルシステムなのでディスクユーティリティーでフォーマットして，システムの日付を過去の日付にしておく。
事前に作っておいたEl Captainのインストールメディア(160GBHDD)から起動して内蔵SSDにMacOSをインストールする。
今回はHDDからSSDへの変更なので起動ディスクをUSBで外付けにしてそのまま転送する。MacOS El Captainをインストール後に移行アシスタントを使ってHDDからSSDにユーザーデータやネットワークの設定を移行する。転送中のプログレスバーだけでなく転送速度も表示してくれるのがありがたい。 HDDの容量は減ってしまったけどシステムの起動やアプリケーションの立ち上がりが，かなりスピードアップした。
純正HDDはなぜが1.5Gbpsでしかネゴシエーションしていなくて立ち上がりが遅い原因はディスクI/Oだったようだ。 SSDは何度も書き込みを繰り返すと寿命がくるので交換したSSDの状態をしりたいのでsmartmontoolsをインストールする。 brewをインストールするとビルドに必要なXcode Command Line Toolsも一緒にインストールしてくれて簡単で助かるなぁ。

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

brew install smartmontools

smartmontoolがインストール出来たのでsmartctlを使ってSSDの健全度を把握する。

$ smartctl -A /dev/disk0s2

$ smartctl -A /dev/disk0s2
smartctl 6.6 2017-11-05 r4594 [Darwin 14.5.0 x86_64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION ===
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000f   100   100   046    Pre-fail  Always       -       0
  2 Throughput_Performance  0x0005   100   100   030    Pre-fail  Offline      -       0
  3 Spin_Up_Time            0x0003   100   100   025    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   093   093   000    Old_age   Always       -       33961
  5 Reallocated_Sector_Ct   0x0033   100   100   024    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000f   100   100   047    Pre-fail  Always       -       0
  8 Seek_Time_Performance   0x0005   100   100   019    Pre-fail  Offline      -       0
  9 Power_On_Hours          0x0032   064   064   000    Old_age   Always       -       18172
 10 Spin_Retry_Count        0x0013   100   100   020    Pre-fail  Always       -       0
 12 Power_Cycle_Count       0x0032   096   096   000    Old_age   Always       -       20122
160 Unknown_Attribute       0x0032   100   100   000    Old_age   Always       -       0
192 Power-Off_Retract_Count 0x0032   095   095   000    Old_age   Always       -       859117454744
193 Load_Cycle_Count        0x0032   072   072   000    Old_age   Always       -       576690
194 Temperature_Celsius     0x0022   100   100   000    Old_age   Always       -       32 (Min/Max 4/54)
195 Hardware_ECC_Recovered  0x001a   100   100   000    Old_age   Always       -       0
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0010   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x003e   200   253   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x000f   100   100   060    Pre-fail  Always       -       0
203 Run_Out_Cancel          0x0002   100   100   000    Old_age   Always       -       0
240 Head_Flying_Hours       0x003e   200   200   000    Old_age   Always       -       0
254 Free_Fall_Sensor        0x0032   100   100   000    Old_age   Always       -       7467

$ smartctl -i /dev/disk0s2

$ smartctl -i /dev/disk0s2
smartctl 6.6 2017-11-05 r4594 [Darwin 15.0.0 x86_64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     Samsung SSD 850 120GB
Serial Number:    
LU WWN Device Id: 5 002538 d427a203c
Firmware Version: MVT01B6Q
User Capacity:    120,034,123,776 bytes [120 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Form Factor:      2.5 inches
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ACS-2, ATA8-ACS T13/1699-D revision 4c
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Thu May 31 20:10:16 2018 JST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

$ smartctl -a /dev/disk0s2

$ smartctl -a /dev/disk0s2
smartctl 6.6 2017-11-05 r4594 [Darwin 15.0.0 x86_64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     Samsung SSD 850 120GB
Serial Number:    
LU WWN Device Id: 5 002538 d427a203c
Firmware Version: MVT01B6Q
User Capacity:    120,034,123,776 bytes [120 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    Solid State Device
Form Factor:      2.5 inches
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ACS-2, ATA8-ACS T13/1699-D revision 4c
SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Thu May 31 20:10:22 2018 JST
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:  (0x00)	Offline data collection activity
					was never started.
					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: 		(    0) seconds.
Offline data collection
capabilities: 			 (0x53) SMART execute Offline immediate.
					Auto Offline data collection on/off support.
					Suspend Offline collection upon new
					command.
					No 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: 	 (  64) minutes.
SCT capabilities: 	       (0x003d)	SCT Status supported.
					SCT Error Recovery Control supported.
					SCT Feature Control supported.
					SCT Data Table supported.

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
  5 Reallocated_Sector_Ct   0x0033   100   100   010    Pre-fail  Always       -       0
  9 Power_On_Hours          0x0032   099   099   000    Old_age   Always       -       16
 12 Power_Cycle_Count       0x0032   099   099   000    Old_age   Always       -       34
177 Wear_Leveling_Count     0x0013   100   100   000    Pre-fail  Always       -       0
179 Used_Rsvd_Blk_Cnt_Tot   0x0013   100   100   010    Pre-fail  Always       -       0
181 Program_Fail_Cnt_Total  0x0032   100   100   010    Old_age   Always       -       0
182 Erase_Fail_Count_Total  0x0032   100   100   010    Old_age   Always       -       0
183 Runtime_Bad_Block       0x0013   100   100   010    Pre-fail  Always       -       0
187 Reported_Uncorrect      0x0032   100   100   000    Old_age   Always       -       0
190 Airflow_Temperature_Cel 0x0032   065   059   000    Old_age   Always       -       35
195 Hardware_ECC_Recovered  0x001a   200   200   000    Old_age   Always       -       0
199 UDMA_CRC_Error_Count    0x003e   100   100   000    Old_age   Always       -       0
235 Unknown_Attribute       0x0012   099   099   000    Old_age   Always       -       24
241 Total_LBAs_Written      0x0032   099   099   000    Old_age   Always       -       236397927

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
  255        0    65535  Read_scanning was never started
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.

けどsmartctlのRAW VALUE(生の値)の十進数表記を見てもよくわからないのでaskubuntuのフォーラムにあったスクリプトをつかったらSSDの状態がわかりやすく出力された。

ssdchk.sh

#!/bin/bash

#######################################
# Variables                           #
#######################################

SSD_DEVICE="/dev/disk0s2"

ON_TIME_TAG="Power_On_Hours"
WEAR_COUNT_TAG="Wear_Leveling_Count"
LBAS_WRITTEN_TAG="Total_LBAs_Written"
LBA_SIZE=512 # Value in bytes

BYTES_PER_MB=1048576
BYTES_PER_GB=1073741824
BYTES_PER_TB=1099511627776

#######################################
# Get total data written...           #
#######################################

# Get SMART attributes
SMART_INFO=$(sudo /usr/local/Cellar/smartmontools/6.6/bin/smartctl -A "$SSD_DEVICE")

# Extract required attributes
ON_TIME=$(echo "$SMART_INFO" | grep "$ON_TIME_TAG" | awk '{print $10}')
WEAR_COUNT=$(echo "$SMART_INFO" | grep "$WEAR_COUNT_TAG" | awk '{print $4}' | sed 's/^0*//')
LBAS_WRITTEN=$(echo "$SMART_INFO" | grep "$LBAS_WRITTEN_TAG" | awk '{print $10}')

# Convert LBAs -> bytes
BYTES_WRITTEN=$(echo "$LBAS_WRITTEN * $LBA_SIZE" | bc)
MB_WRITTEN=$(echo "scale=3; $BYTES_WRITTEN / $BYTES_PER_MB" | bc)
GB_WRITTEN=$(echo "scale=3; $BYTES_WRITTEN / $BYTES_PER_GB" | bc)
TB_WRITTEN=$(echo "scale=3; $BYTES_WRITTEN / $BYTES_PER_TB" | bc)

# Output results...
echo "------------------------------"
echo " SSD Status:   $SSD_DEVICE"
echo "------------------------------"
echo " On time:      $(echo $ON_TIME | sed ':a;s/\B[0-9]\{3\}\>/,&/;ta') hr"
echo "------------------------------"
echo " Data written:"
echo "           MB: $(echo $MB_WRITTEN | sed ':a;s/\B[0-9]\{3\}\>/,&/;ta')"
echo "           GB: $(echo $GB_WRITTEN | sed ':a;s/\B[0-9]\{3\}\>/,&/;ta')"
echo "           TB: $(echo $TB_WRITTEN | sed ':a;s/\B[0-9]\{3\}\>/,&/;ta')"
echo "------------------------------"
echo " Mean write rate:"
echo "        MB/hr: $(echo "scale=3; $MB_WRITTEN / $ON_TIME" | bc | sed ':a;s/\B[0-9]\{3\}\>/,&/;ta')"
echo "------------------------------"
echo " Drive health: ${WEAR_COUNT} %"
echo "------------------------------"

$ ./ssdchk.sh
------------------------------
 SSD Status:   /dev/disk0s2
------------------------------
 On time:      16 hr
------------------------------
 Data written:
           MB: 117247.710
           GB: 114.499
           TB: .111
------------------------------
 Mean write rate:
        MB/hr: 7327.981
------------------------------
 Drive health: 100 %

必要な部分が抜き出されて分かりやすい。そしてこのSSDはあまり使われていない。
　smartctlは便利でいいのだけどUSBなどで外付けのHDDやSSDの状態を知りたいときにはあまり使えないので(いろいろ道具はあるみたいだけどWindows用だし..)SATA接続して状態を把握した。
　ネゴシエーションスピードも3Gbps出ているのでこの時代のマシンでは上等だと思う。よく分かっていないがTRIM機能を有効にしたほうが早くなるようなのでTRIMを有効にする。

trim有効

$ sudo trimforce enable
Password:
IMPORTANT NOTICE:  This tool force-enables TRIM for all relevant attached
devices, even though such devices may not have been validated for data
integrity while using TRIM.  Use of this tool to enable TRIM may result in
unintended data loss or data corruption.  It should not be used in a commercial
operating environment or with important data. Before using this tool, you
should back up all of your data and regularly back up data while TRIM is
enabled.  This tool is provided on an “as is” basis. APPLE MAKES NO WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE,
REGARDING THIS TOOL OR ITS USE ALONE OR IN COMBINATION WITH YOUR DEVICES,
SYSTEMS, OR SERVICES. BY USING THIS TOOL TO ENABLE TRIM, YOU AGREE THAT, TO THE
EXTENT PERMITTED BY APPLICABLE LAW, USE OF THE TOOL IS AT YOUR SOLE RISK AND
THAT THE ENTIRE RISK AS TO SATISFACTORY QUALITY, PERFORMANCE, ACCURACY AND
EFFORT IS WITH YOU.
Are you sure you wish to proceed (y/N)? y
Your system will immediately reboot when this is complete.
Is this OK (y/N)? y
Enabling TRIM...
.
.
Operation succeeded. Your system will reboot momentarily, please wait...

自動的に再起動がかかるんだな.

起動時間はどうなったかというと

デバイス種類	経過時間	状態
HDD	1分53秒	ユーザ選択画面
SSD	28秒	ユーザ選択画面

起動中のプログレスバーが異常に早いし，起動時間は半分以下になっている。もうMacBookが発売されて10年経っているけど，これほど息の長いマシンになるとは思わなかった。

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