A.4.3. How MySQL Handles a Full Disk
This section describes how MySQL responds to disk-full errors
(such as “no space left on device”), and to
quota-exceeded errors (such as “write failed” or
“user block limit reached”).
This section is relevant for writes to MyISAM
tables. It also applies for writes to binary log files and
binary log index file, except that references to
“row” and “record” should be
understood to mean “event.”
When a disk-full condition occurs, MySQL does the following:
It checks once every minute to see whether there is enough
space to write the current row. If there is enough space, it
continues as if nothing had happened.
Every 10 minutes it writes an entry to the log file, warning
about the disk-full condition.
To alleviate the problem, you can take the following actions:
To continue, you only have to free enough disk space to
insert all records.
To abort the thread, you must use mysqladmin
kill. The thread is aborted the next time it
checks the disk (in one minute).
Other threads might be waiting for the table that caused the
disk-full condition. If you have several
“locked” threads, killing the one thread that
is waiting on the disk-full condition allows the other
threads to continue.
Exceptions to the preceding behavior are when you use
REPAIR TABLE or OPTIMIZE
TABLE or when the indexes are created in a batch after
LOAD DATA INFILE or after an ALTER
TABLE statement. All of these statements may create
large temporary files that, if left to themselves, would cause
big problems for the rest of the system. If the disk becomes
full while MySQL is doing any of these operations, it removes
the big temporary files and mark the table as crashed. The
exception is that for ALTER TABLE, the old
table is left unchanged.
