F20 System Wide Change: No Default Syslog

[Glen Turner]

Hi Lennart,

I suppose someone should mention small flash-disk-only computers.

There traditionally we fling syslog messages to the serial console or a LRU buffer in RAM (often the dmesg buffer). The point is to avoid I/O on the flash memory. Syslog daemons tend to do a lot of fsync-ed I/O, which just chews up flash write cycles. With some configuration the syslog daemons can be made to not to fsync, and with additional configuration to write to the serial port or to the dmesg ring buffer.

These small computers aren't specialised embedded systems anymore -- if you buy a cheap ARM-based laptop then you are buying a such a system. Their increasing popularity is very much the reason ARM is becoming a top-teir architecture in Fedora. These systems are *cheap*, so they don't have the write cycles of an expensive SSD.

I'm not across journald at all. But the questions in my mind are:

- Is is possible to run journald without writing to disk; that is: to serial as text, or as binary to a ring buffer which can then by used by journalctl?

- When writing to disk does journald fsync, and if so can that be disabled by a non-guru laptop user?

- Is journalctl available from the dracut shell, so that we can get bug reports for early system failures? There is a lot more variation in small computers, and thus more early system failures.

Thank you for making the binary format portable between computers. Allowing a 32b ARM journal file to be displayed on a x86_64 desktop is very useful.

Thank you for your time, glen