HAMMER2 corruption bug and fix

It’s possible to have data corrupted on a HAMMER2 volume during a specific combination of a bulkfree operation and a lot of writing to disk.  Matthew Dillon has a potential fix already.  As he announced, it’s scheduled to go into 5.4 this weekend.  It’s a rare bug, but if you want to check for it, look for CHECK FAIL entries in /var/log/messages.

And because every cloud has a silver lining: some not-yet-quantified performance improvements.

 

Cleanly adding sysctl entries on DragonFly

If you’d like to set a particular sysctl(8), you enter it into /etc/sysctl.conf. A common mistake is to copy the command line and put “sysctl foo=bar” in sysctl.conf instead of “foo=bar”. This used to cause a warning, but it still bit people, as it would cause a long stream of error messages during boot – with no clear reason, as the kernel tried to understand the command. Now, that typo is handled automatically.