[root@XXX XXX]# mariadb-backup --prepare --target-dir=/mnt/backup/XXX/mariadb/$dt

mariadb-backup based on MariaDB server 10.5.10-7-MariaDB Linux (x86_64)

[00] 2021-10-06 19:21:30 cd to /mnt/backup/XXX/mariadb/202110061912/

[00] 2021-10-06 19:21:30 open files limit requested 0, set to 1024

[00] 2021-10-06 19:21:31 This target seems to be not prepared yet.

[00] 2021-10-06 19:21:31 mariabackup: using the following InnoDB configuration for recovery:

[00] 2021-10-06 19:21:31 innodb_data_home_dir = .

[00] 2021-10-06 19:21:31 innodb_data_file_path = ibdata1:12M:autoextend

[00] 2021-10-06 19:21:31 innodb_log_group_home_dir = .

[00] 2021-10-06 19:21:31 InnoDB: Using Linux native AIO

[00] 2021-10-06 19:21:31 Starting InnoDB instance for recovery.

[00] 2021-10-06 19:21:31 mariabackup: Using 104857600 bytes for buffer pool (set by --use-memory parameter)

2021-10-06 19:21:31 0 [Note] InnoDB: Uses event mutexes

2021-10-06 19:21:31 0 [Note] InnoDB: Compressed tables use zlib 1.2.11

2021-10-06 19:21:31 0 [Note] InnoDB: Number of pools: 1

2021-10-06 19:21:31 0 [Note] InnoDB: Using crc32 + pclmulqdq instructions

2021-10-06 19:21:31 0 [Note] InnoDB: Using Linux native AIO

2021-10-06 19:21:31 0 [Note] InnoDB: Initializing buffer pool, total size = 104857600, chunk size = 104857600

2021-10-06 19:21:31 0 [Note] InnoDB: Completed initialization of buffer pool

2021-10-06 19:21:31 0 [Warning] InnoDB: Retry attempts for reading partial data failed.

2021-10-06 19:21:31 0 [ERROR] InnoDB: Operating system error number 13 in a file operation.

2021-10-06 19:21:31 0 [ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.

2021-10-06 19:21:31 0 [ERROR] [FATAL] InnoDB: Tried to read 5120 bytes at offset 2048, but was only able to read 0.Cannot read from file. OS error number 13.

211006 19:21:31 [ERROR] mysqld got signal 6 ;

This could be because you hit a bug. It is also possible that this binary

or one of the libraries it was linked against is corrupt, improperly built,

or misconfigured. This error can also be caused by malfunctioning hardware.

To report this bug, see https://mariadb.com/kb/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help

diagnose the problem, but since we have already crashed, 

something is definitely wrong and this may fail.

Server version: 10.5.10-7-MariaDB-enterprise

key_buffer_size=0

read_buffer_size=131072

max_used_connections=0

max_threads=1

thread_count=0

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 6057 K  bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0

Attempting backtrace. You can use the following information to find out

where mysqld died. If you see no messages after this, something went

terribly wrong...

stack_bottom = 0x0 thread_stack 0x49000

addr2line: 'mariadb-backup': そのようなファイルはありません

mariadb-backup(my_print_stacktrace+0x2e)[0x55d5918a29be]

Printing to addr2line failed

mariadb-backup(handle_fatal_signal+0x485)[0x55d5913907d5]

sigaction.c:0(__restore_rt)[0x7fc2610d7b20]

:0(__GI_raise)[0x7fc26041c37f]

:0(__GI_abort)[0x7fc260406db5]

addr2line: 'mariadb-backup': そのようなファイルはありません

mariadb-backup(+0x65fc95)[0x55d590fdbc95]

mariadb-backup(+0x642ef4)[0x55d590fbeef4]

mariadb-backup(+0xd737c2)[0x55d5916ef7c2]

mariadb-backup(+0xd5e3c0)[0x55d5916da3c0]

mariadb-backup(+0xd65e23)[0x55d5916e1e23]

mariadb-backup(+0xd690ea)[0x55d5916e50ea]

mariadb-backup(+0xd69654)[0x55d5916e5654]

mariadb-backup(+0x65828b)[0x55d590fd428b]

mariadb-backup(+0x6b2b1b)[0x55d59102eb1b]

mariadb-backup(main+0x181)[0x55d590febdc1]

??:0(__libc_start_main)[0x7fc260408493]

addr2line: 'mariadb-backup': そのようなファイルはありません

mariadb-backup(_start+0x2e)[0x55d59101d9de]

The manual page at https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains

information that should help you find out what is causing the crash.

Writing a core file...

Working directory at /mnt/backup/XXX/mariadb/202110061912

Resource Limits:

Limit                     Soft Limit           Hard Limit           Units     

Max cpu time              unlimited            unlimited            seconds   

Max file size             unlimited            unlimited            bytes     

Max data size             unlimited            unlimited            bytes     

Max stack size            8388608              unlimited            bytes     

Max core file size        unlimited            unlimited            bytes     

Max resident set          unlimited            unlimited            bytes     

Max processes             158623               158623               processes 

Max open files            1024                 262144               files     

Max locked memory         65536                65536                bytes     

Max address space         unlimited            unlimited            bytes     

Max file locks            unlimited            unlimited            locks     

Max pending signals       158623               158623               signals   

Max msgqueue size         819200               819200               bytes     

Max nice priority         0                    0                    

Max realtime priority     0                    0                    

Max realtime timeout      unlimited            unlimited            us        

Core pattern: |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e

中止 (コアダンプ)

[root@XXX ~]# df -h

....

//xxx.xx.xx.xxx/Share 3.7T 86G 3.6T 3% /mnt/data

//xxx.xx.xx.xxx/Backup 3.7T 86G 3.6T 3% /mnt/backup

tmpfs 3.9G 4.0K 3.9G 1% /run/user/1000

[root@XXX ~]# cat /etc/selinux/config

# This file controls the state of SELinux on the system.

# SELINUX= can take one of these three values:

# enforcing - SELinux security policy is enforced.

# permissive - SELinux prints warnings instead of enforcing.

# disabled - No SELinux policy is loaded.

SELINUX=permissive

# SELINUXTYPE= can take one of these three values:

# targeted - Targeted processes are protected,

# minimum - Modification of targeted policy. Only selected processes are protected.

# mls - Multi Level Security protection.

SELINUXTYPE=targeted

The execution logs for each are attached.

- NAS

- Local Storage

Investigate the cause of the following error that occurs when executing "prepare" in the backup directory on the NAS.

(When I copy the file to local storage and run "prepare", it terminates normally, so there seems to be no problem with the backup file.)

```

2021-10-29 20:18:10 0 [Warning] InnoDB: Retry attempts for reading partial data failed.

2021-10-29 20:18:10 0 [ERROR] InnoDB: Operating system error number 13 in a file operation.

2021-10-29 20:18:10 0 [ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.

2021-10-29 20:18:10 0 [ERROR] [FATAL] InnoDB: Tried to read 65536 bytes at offset 2048, but was only able to read 0.Cannot read from file. OS error number 13.

```