mysql not working , it is not starting - mysql

here is a bit of the error log .
160422 10:45:00 [Note] InnoDB: The log sequence numbers 1665244 and 1665244 in ibdata files do not match the log sequence number 15857945 in the ib_logfiles!
160422 10:45:00 [Note] InnoDB: Database was not shutdown normally!
160422 10:45:00 [Note] InnoDB: Starting crash recovery.
160422 10:45:00 [Note] InnoDB: Reading tablespace information from the .ibd files...
160422 10:45:00 [Note] InnoDB: Restoring possible half-written data pages
160422 10:45:00 [Note] InnoDB: from the doublewrite buffer...
160422 10:45:00 [Note] InnoDB: 128 rollback segment(s) are active.
160422 10:45:00 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.6.22-72.0 started; log sequence number 15857945
160422 10:45:00 [Note] InnoDB: !!! innodb_force_recovery is set to 2 !!!
160422 10:45:00 [Note] Plugin 'FEEDBACK' is disabled.
160422 10:45:00 [Note] Server socket created on IP: '::'.
160422 10:45:00 [ERROR] mysqld.exe: Table '.\mysql\db' is marked as crashed and last (automatic?) repair failed
160422 10:45:00 [ERROR] Fatal error: Can't open and lock privilege tables: Table '.\mysql\db' is marked as crashed and last (automatic?) repair failed
plz somebody help , i have one important database ,whose backup i have not made , i posted this question earlier ,but didnt got the answer ...this started when i was trying to access phpmyadmin , from then on mysql is not starting.

I see two potential ways out of it.
For the following:
Table '.\mysql\db' is marked as crashed and last (automatic?) repair failed
You can use mysqlcheck to repair it, if it is a MyISAM DB. Else try the InnoDB force recovery option if it is InnoDB database. You can start your DB with InnoDB force recovery and take a DB dump from it, to restore it on a fresh MySQL install.
In future, try enabling innodb_file_per_table option.
Now, second option. Even though the first one looks most likely.
The log sequence numbers 1665244 and 1665244 in ibdata files do not match the log sequence number 15857945 in the ib_logfiles!
If the first method doesnt work, give this a try. It looks like the ib_logfiles are corrupt, I faced this issue before and used the following steps to get my DB up and working:
Take a full backup of your mysql datadir in another directory.
Make sure mysql service is stopped.
remove the ib_logfile1 and ib_logfile2
Start the MySQL service
Hope it helps

Rishav, innodb_force_recovery doesn't recover anything. It is a mode you start your mysql with. Once it starts, you should be able to take a dump. Following should be the steps:
Steps to get it back up.
1. Stop mysqld.
2. Backup /var/lib/mysql/ib*
3. Add the following line into /etc/my.cnf
innodb_force_recovery = 4
4. Restart mysqld.
5. Dump your DB using mysqldump to a dump.sql file.
6. Drop all databases which need recovery.
7. Stop mysqld.
8. Remove /var/lib/mysql/ib*
9. Comment out innodb_force_recovery in /etc/my.cnf
10. Restart mysqld. Look at mysql error log. By default it should be /var/lib/mysql/server/hostname.com.err to see how it creates new ib* files. (Although, I recommend a fresh setup here)
11. Restore databases from the dump:mysql < dump.sql

Related

Why won't mySQL start?

I've tried many things said on the internet, also tried to fix it myself, but I don't have any clue, what I could do next. I can't Reinstall it, because there is important data on it.
The log:
htts://mariadb.com/kb/en/library/innodb-recovery-modes/ for information about forcing recovery.
2022-12-31 0:32:28 2 [ERROR] InnoDB: Page [page id: space=24, page number=1] log sequence number 300669 is in the future! Current system log sequence number 300459.
2022-12-31 0:32:28 2 [ERROR] InnoDB: Your database may be corrupt or you may have copied the InnoDB tablespace but not the InnoDB log files. Please refer to htts://mariadb.com/kb/en/library/innodb-recovery-modes/ for information about forcing recovery.
2022-12-31 0:32:28 0 [Note] InnoDB: 10.4.27 started; log sequence number 300450; transaction id 214
2022-12-31 0:32:28 0 [Note] InnoDB: Loading buffer pool(s) from C:\xampp\mysql\data\ib_buffer_pool
2022-12-31 0:32:28 0 [Note] Plugin 'FEEDBACK' is disabled.
2022-12-31 0:32:28 0 [Note] Server socket created on IP: '::'.
I've tried updateing the config.
I've tried booting without password.
There are currently two methods:
Modify the value of innodb_force_recovery in the parameter file, and then start the database. If it succeeds, you need to export the data, then recreate the database, and then import the data. If not, refer to the second point.
There are some tools, some paid and some free. You can retrieve the data through the ibdata file, and rebuild the database after retrieval.
Of course it is very important not to delete the data files

MAMP Pro can't start MySQL

I had to force a shutdown when my computer froze, and MAMP has been unable to start MySql since then. I have tried deleting the log files from MAMP/DB/mysql and restarting MAMP, but it hasn't worked. I also tried entering sudo killall -9 mysqld in the terminal, to no avail.
Here is the error log from MAMP:
2017-05-12 16:05:49 4691 [Note] InnoDB: The log sequence numbers 730255276 and 730255276 in ibdata files do not match the log sequence number 730624549 in the ib_logfiles!2017-05-12 16:05:49 4691 [Note] InnoDB: Database was not shutdown normally!
2017-05-12 16:05:49 4691 [Note] InnoDB: Starting crash recovery.
2017-05-12 16:05:49 4691 [Note] InnoDB: Reading tablespace information from the .ibd files...
2017-05-12 16:05:50 4691 [ERROR] InnoDB: Attempted to open a previously opened tablespace. Previous tablespace mysql/slave_worker_info uses space ID: 5 at filepath: ./mysql/slave_worker_info.ibd. Cannot open tablespace wordpress#0020test#0020site/wp_term_taxonomy which uses space ID: 5 at filepath: ./wordpress#0020test#0020site/wp_term_taxonomy.ibd
2017-05-12 16:05:50 7fff7303b000 InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: If you are installing InnoDB, remember that you must create
InnoDB: directories yourself, InnoDB does not create them.
InnoDB: Error: could not open single-table tablespace file ./wordpress#0020test#0020site/wp_term_taxonomy.ibd
InnoDB: We do not continue the crash recovery, because the table may become
InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it.
InnoDB: To fix the problem and start mysqld:
InnoDB: 1) If there is a permission problem in the file and mysqld cannot
InnoDB: open the file, you should modify the permissions.
InnoDB: 2) If the table is not needed, or you can restore it from a backup,
InnoDB: then you can remove the .ibd file, and InnoDB will do a normal
InnoDB: crash recovery and ignore that table.
InnoDB: 3) If the file system or the disk is broken, and you cannot remove
InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf
InnoDB: and force InnoDB to continue crash recovery here.
170512 16:05:50 mysqld_safe mysqld from pid file /Applications/MAMP/tmp/mysql/mysql.pid ended
Any ideas?
I've just had the same problem with MAMP.
To solve the problem, i was forced to delete the file that causes the error located in "Applications/MAMP/db/mysql56/bib" and then recreate the TABLE/BASE afterwards.
I hope that would be helpful.

XAMPP: MySQL does not start after crash

There are aready several questions regarding that MySQL fails to start when running XAMPP, but unfortunately I couldn't figure out a solution from these.
Here is my case:
I installed XAMPP for Linux 5.6.14-3 and when I ran it yesterday everything worked fine.
Today, I ran XAMPP again:
/opt/lampp$ sudo ./xampp start
Starting XAMPP for Linux 5.6.14-3...
XAMPP: Starting Apache...ok.
XAMPP: Starting MySQL...ok.
XAMPP: Starting ProFTPD...ok.
Then I open localhost in the browser bringing me to the xampp dashboard. There I click on the phpMyAdmin menu entry, which gives me:
Error
MySQL said:
Cannot connect: invalid settings.
Connection for controluser as defined in your configuration failed.
phpMyAdmin tried to connect to the MySQL server,
and the server rejected the connection.
You should check the host, username and password
in your configuration and make sure that they
correspond to the information given by the
administrator of the MySQL server.
I think that I made sure that the control user has the right pass.
The problem rather seems to be that MySQL does not really start although it says 'ok' (see above). Since, when I stop XAMPP, I get:
/opt/lampp$ sudo ./xampp stop
Stopping XAMPP for Linux 5.6.14-3...
XAMPP: Stopping Apache...ok.
XAMPP: Stopping MySQL...not running.
XAMPP: Stopping ProFTPD...ok.
Looking at the error_log of xampp, there is a single entry, which looks suspicious (though I don't really understand it), saying:
[Sun Nov 15 11:38:59.737875 2015] [mpm_prefork:notice] [pid 6217] AH00169: caught SIGTERM, shutting down
So, if anybody is able to locate the problem or give me hints for a fix, I would really apreciate. Thanks already!
Edit - problem "fixed" (without knowing, what I've really done, though)
Here's the MySQL error-log (located at /opt/lampp/var/mysql/[computername].err):
2015-11-15 15:52:44 10864 mysqld_safe Starting mysqld daemon with databases from /opt/lampp/var/
2015-11-15 15:52:44 140410457307008 [Note] Using unique option prefix 'key_buffer' is error-prone and can break in the future. Please use the full name 'key_buffer_size' instead.
2015-11-15 15:52:44 140410457307008 [Note] /opt/lampp/sbin/mysqld (mysqld 10.1.8-MariaDB) starting as process 11011 ...
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Using mutexes to ref count buffer pool pages
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: The InnoDB memory heap is disabled
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Memory barrier is not used
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Compressed tables use zlib 1.2.8
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Using CPU crc32 instructions
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Initializing buffer pool, size = 16.0M
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Completed initialization of buffer pool
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Highest supported file format is Barracuda.
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: The log sequence numbers 3813213 and 3813213 in ibdata files do not match the log sequence number 9929741 in the ib_logfiles!
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Database was not shutdown normally!
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Starting crash recovery.
2015-11-15 15:52:44 140410457307008 [Note] InnoDB: Reading tablespace information from the .ibd files...
2015-11-15 15:52:44 140410457307008 [ERROR] InnoDB: Attempted to open a previously opened tablespace. Previous tablespace bitnami_joomla/jos_content_frontpage uses space ID: 14 at filepath: ./bitnami_joomla/jos_content_frontpage.ibd. Cannot open tablespace phpmyadmin/pma__bookmark which uses space ID: 14 at filepath: ./phpmyadmin/pma__bookmark.ibd
2015-11-15 15:52:44 7fb3db6e3780 InnoDB: Operating system error number 2 in a file operation.
InnoDB: The error means the system cannot find the path specified.
InnoDB: If you are installing InnoDB, remember that you must create
InnoDB: directories yourself, InnoDB does not create them.
InnoDB: Error: could not open single-table tablespace file ./phpmyadmin/pma__bookmark.ibd
InnoDB: We do not continue the crash recovery, because the table may become
InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it.
InnoDB: To fix the problem and start mysqld:
InnoDB: 1) If there is a permission problem in the file and mysqld cannot
InnoDB: open the file, you should modify the permissions.
InnoDB: 2) If the table is not needed, or you can restore it from a backup,
InnoDB: then you can remove the .ibd file, and InnoDB will do a normal
InnoDB: crash recovery and ignore that table.
InnoDB: 3) If the file system or the disk is broken, and you cannot remove
InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf
InnoDB: and force InnoDB to continue crash recovery here.
2015-11-15 15:52:44 10864 mysqld_safe mysqld from pid file /opt/lampp/var/mysql/[computername].pid ended
First try: I made a backup of the directory /opt/lampp/var/mysql/phpmyadmin/ and added
innodb_force_recovery = 1
at the end of /opt/lampp/etc/my.conf. That gave me still the same error when starting MySQL again.
Next try was removing the file pma__bookmarks.idb from the directory, which had the effect that the error now complained about pma__favorites instead.
Finally, I removed all pma__*.idb-files and voila! MySQL is running, and I can access the phpMyAdmin-pages.
Works for me, though I don't know what was lost be removing the pma-databases? (They were not restored in any way, as it seems...)
Probably, the database-files were corrupted, when my computer went down, and they were still running!?
You must check whether mysqld process exist in top and then either try to connect with mysql command line client or review MySQL Error log. Sometimes xampp may be confused by MySQL Server which e.g. comes pre-installed with OS.

Error Starting MySQL after Crash

I was merrily installing wordpress with MAMP pro when my Mac crashed. Now I cannot start MySql. Most stuff I read online tells me to throw some terminal commands at it, trying to kill the process.
killall -9 mysqld
But terminal report "No matching processes belonging to you were found"
So I have had a look in the log and can see this from the time of the first restart attempt after the crash
150506 21:11:33 mysqld_safe Starting mysqld daemon with databases from /Library/Application Support/appsolute/MAMP PRO/db/mysql
150506 21:11:33 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.
150506 21:11:33 [Warning] Setting lower_case_table_names=2 because file system for /Library/Application Support/appsolute/MAMP PRO/db/mysql/ is case insensitive
150506 21:11:33 [Note] Plugin 'FEDERATED' is disabled.
150506 21:11:33 InnoDB: The InnoDB memory heap is disabled
150506 21:11:33 InnoDB: Mutexes and rw_locks use GCC atomic builtins
150506 21:11:33 InnoDB: Compressed tables use zlib 1.2.3
150506 21:11:33 InnoDB: Initializing buffer pool, size = 128.0M
150506 21:11:33 InnoDB: Completed initialization of buffer pool
InnoDB: The first specified data file ./ibdata1 did not exist:
InnoDB: a new database to be created!
150506 21:11:33 InnoDB: Setting file ./ibdata1 size to 10 MB
InnoDB: Database physically writes the file full: wait...
150506 21:11:33 InnoDB: Log file ./ib_logfile0 did not exist: new to be created
InnoDB: Setting log file ./ib_logfile0 size to 5 MB
InnoDB: Database physically writes the file full: wait...
150506 21:11:33 InnoDB: Log file ./ib_logfile1 did not exist: new to be created
InnoDB: Setting log file ./ib_logfile1 size to 5 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Doublewrite buffer not found: creating new
InnoDB: Doublewrite buffer created
InnoDB: 127 rollback segment(s) active.
InnoDB: Creating foreign key constraint system tables
InnoDB: Foreign key constraint system tables created
150506 21:11:34 InnoDB: Waiting for the background threads to start
150506 21:11:35 InnoDB: 5.5.42 started; log sequence number 0
150506 21:11:35 [Note] Event Scheduler: Loaded 0 events
150506 21:11:35 [Note] /Applications/MAMP/Library/bin/mysqld: ready for connections.
Version: '5.5.42' socket: '/Applications/MAMP/tmp/mysql/mysql.sock' port: 0 Source distribution
150506 21:16:44 [Note] /Applications/MAMP/Library/bin/mysqld: Normal shutdown
So Table Space size error.. I am very much a front end guy and have no idea where to begin with this...??
Help please, I really can't afford to loose the last week of work.
Thanks you
As you pointed out InnoDB tablespace is corrupt, so InnoDB fails to start.
InnoDB can tolerate some errors if you start it with option innodb_force_recovery. Try values from 1 to 6 until MySQL starts.
If you're lucky and MySQL starts with innodb_force_recovery then dump all tables into an sql file with mysqldump and re-create MySQL database from scratch. I.e. move existing files to some safe place, start mysql_install_db, change file permissions and start MySQL. Then load the database back.
If you're less lucky and MySQL doesn't start with innodb_force_recovery=6 then check how to Recover Corrupt MySQL Database .
And to avoid this experience in future use XtraBackup for Mac OS to take backups.
Please see her:
MAMP PRO crashes; MySQL will not start on reboot
Thanks for the heads up with Xtrabackup for MacOS, one to keep an eye on that.

Getting error "Plugin 'InnoDB' registration as a STORAGE ENGINE failed" when starting MySQL

I found many similar question on Stackoverflow but didn't get the exact error solution.
My issue is when starting MySQL service on one of the Dedicated Centos 6.5 machine, I am getting error :
141018 05:13:46 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
141018 5:13:47 [Warning] Can't create test file /var/lib/mysql/ip-184-168-73-83.lower-test
141018 5:13:47 [Warning] Can't create test file /var/lib/mysql/ip-184-168-73-83.lower-test
/usr/libexec/mysqld: Can't create/write to file '/tmp/ibkTWnhE' (Errcode: 28)
141018 5:13:48 InnoDB: Error: unable to create temporary file; errno: 28
141018 5:13:48 [ERROR] Plugin 'InnoDB' init function returned error.
141018 5:13:48 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
141018 5:13:48 [ERROR] Can't start server : Bind on unix socket: No space left on device
141018 5:13:48 [ERROR] Do you already have another mysqld server running on socket: /var/lib/mysql/mysql.sock ?
141018 5:13:48 [ERROR] Aborting
141018 5:13:48 [Note] /usr/libexec/mysqld: Shutdown complete
141018 05:13:48 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
Here are free command status:
free -m
total used free shared buffers cached
Mem: 3743 3631 111 0 2705 21
-/+ buffers/cache: 905 2838
Swap: 2047 0 2047
This error also happens when your Database data is corrupt. You may fix this issue by moving your Db data files (ib_logfile0 and ib_logfile1) mentioned below to another location. ib_logfile0 and ib_logfile1 are system tablespace for the InnoDB infrastructure. These files contains several classes for information vital for InnoDB. You may read about these files here.
Before following below steps please keep a copy of files (ib_logfile0 and ib_logfile1) so you may restore your data in case it is lost:
Follow below steps:
Login to server via SSH with root access.
Navigate to /var/lib/mysql.
If you see files like, ib_logfile0 and ib_logfile1, rename or move them to some other folder.
Stop and start the MySQL service by running sudo service mysql stop and sudo service mysql start
These files will be recreated after you restart the server and the issue will be fixed hopefully.
Thanks
I have the same problems, this my solution:
Add more RAM to the server
Decrease the value of innodb-buffer-pool size in the config file:
sudo nano /etc/mysql/my.cnf
innodb_buffer_pool_size = 10M
After save /etc/mysql/my.cnf.
Restart mysql service:
sudo service mysql restart
exit
This is frequently occurred issue. Do following -
delete/move out these "aria_log_contro, ib_logfile0, ib_logfile1, ib_data1" files from location "..\xampp\mysql\data" and also from "..\xampp\mysql\backup".
stop and start apache server and mysql form xampp control panel
This should fix the issue; actually it worked for me.
NOTE: THIS IS GOING TO RESET THE DB IN MANY CASES BE VERY CAREFUL
Changing the values of innodb_buffer_pool_size and innodb_log_file_size didn't work for me.
Moving ib_logfile0 and ib_logfile1 files didn't help either.
What did help was:
> service mysql stop
Edit my.cfg and add innodb_force_recovery = 1
> service mysql start
> service mysql stop
Comment the innodb_force_recovery = 1 line.
> service mysql start
And voilá. (I should note that I have no idea if this involves any data loss or not)
Although late but putting answer here so that solution that helped me can help someone. I took following steps:
Added more RAM to sever
Decrease the value of innodb-buffer-pool size
Set innodb_log_file_size
Restart mysql
Example of addition to my.cnf:
innodb_buffer_pool_size = 10M
innodb_log_file_size = 1000M
After few unsuccess hours, i checked the disk space... and was full...
I was getting below mysql error log:-
[Note] Plugin 'FEDERATED' is disabled.
InnoDB: The InnoDB memory heap is disabled
InnoDB: Mutexes and rw_locks use GCC atomic builtins
InnoDB: Compressed tables use zlib 1.2.3
InnoDB: Using Linux native AIO
InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137363456 bytes) failed; errno 12
InnoDB: Completed initialization of buffer pool
InnoDB: Fatal error: cannot allocate memory for the buffer pool
[ERROR] Plugin 'InnoDB' init function returned error.
[ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
[ERROR] Unknown/unsupported storage engine: InnoDB
[ERROR] Aborting
[Note] /usr/libexec/mysqld: Shutdown complete
I found out there are two solutions which are:-
1)Set innodb_log_file_size equal to the actual size of the existing InnoDB log files.
To see what size of innoDB log allocated, login mysql and enter following cmd:-
SHOW GLOBAL VARIABLES LIKE 'innodb_log_file_size';
Expected result example:- 5242880
After that, insert that value in my.cnf:-
vi /etc/my.cnf
innodb_log_file_size =5242880
2)Rename or move both the ./ib_logfile0 and ./ib_logfile1 files, and then start the MySQL server.This normally will be located at /var/lib/mysql. After start mysql, it create new innoDB log file and restore possible half-written data from the file of .ibd.
The expexted mysql log example:-
InnoDB: Database physically writes the file full: wait...
161216 9:58:54 InnoDB: Log file ./ib_logfile1 did not exist: new to be created
InnoDB: Setting log file ./ib_logfile1 size to 5 MB
InnoDB: Database physically writes the file full: wait...
161216 9:58:54 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the ib_logfiles!
161216 9:58:54 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
161216 9:58:54 InnoDB: Waiting for the background threads to start
161216 9:58:55 InnoDB: 5.5.50 started; log sequence number 1589772
161216 9:58:55 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306
161216 9:58:55 [Note] - '0.0.0.0' resolves to '0.0.0.0';
161216 9:58:55 [Note] Server socket created on IP: '0.0.0.0'.
161216 9:58:55 [Note] Event Scheduler: Loaded 0 events
161216 9:58:55 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.5.50' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL) by Remi
References:-
JUSTIN KULESZA (2011). MySQL: Failed Registration of InnoDB as a Storage Engine. Available at: https://spin.atomicobject.com/2011/05/09/mysql-failed-registration-of-innodb-as-a-storage-engine/.
RolandoMySQLDBA (2014). MySQL my.cnf: innodb_log_file_size is missing. Available at: https://dba.stackexchange.com/questions/75688/mysql-my-cnf-innodb-log-file-size-is-missing/158325#158325
Changing the Number or Size of InnoDB Redo Log Files. Available at: http://dev.mysql.com/doc/refman/5.7/en/innodb-data-log-reconfiguration.html
Nothing was working with reinstalls, removes, and others (I had no data to keep, not a fix; more of a data destruction process, big caveat there):
1005 mysql_install_db
1007 /usr/bin/mysqld_safe --datadir='/var/lib/mysql
1008 /usr/bin/mysqld_safe --datadir='/var/lib/mysql' (^z)
1009 bg
1010 mysql
1011 mysql_secure_installation
1012 mysql
1013 mysql -p
And viola; actually usable database.
for me the solution was to change the config to add
innodb_use_native_aio = 0
in mysql config
Just move this log file (ib_logfile0) to some other place for safer side and start the mysql services it worked for me.
I also met the same issue when restore a backup set made via innobackupex to a new instance. Finally ,the root cause is innodb_log_file_size doesn't match original instance that take the backup, and fix steps by steps like below:
Get innodb_log_file_size value from oragin instance via below command:
mysql uroot -ppasswd -NBe "show global variables like 'innodb_log_file_size';"
Modify the /etc/my.cnf of new instance with last get value:
vim /etc/my.cnf
Restart mysqld via :
systemctl restart mysqld