<p>I have  a RHEL 5 system with a fresh new hard drive I just dedicated to the MySQL server. To get things started, I used "mysqldump --host otherhost -A | mysql", even though I noticed the manpage never explicitly recommends trying this (mysqldump into a file is a no-go. We're talking 500G of database). </p>

<p>This process fails at random intervals, complaining that too many files are open (at which  point mysqld gets the relevant signal, and dies and respawns). </p>

<p>I tried upping it at sysctl and ulimit, but the problem persists. What do I do about it? </p>

mysqldump by default performs a per-table lock of all involved tables. If you have many tables that can exceed the amount of file descriptors of the mysql server process.
Try --skip-lock-tables or if locking is imperative --lock-all-tables.
http://dev.mysql.com/doc/refman/5.1/en/mysqldump.html
```
--lock-all-tables, -x
Lock all tables across all databases. This is achieved by acquiring a global read lock for the duration of the whole dump. This option automatically turns off --single-transaction and --lock-tables.
```