[GTALUG] Question Fodder: Bcache Filesystem

[Jamon Camisso]

On 5/14/19 5:12 PM, Christopher Browne via talk wrote:
> Sounds like it may be the wrong moment in time to be adopting
> BCache-related stuff ;-)
> 
> Has anyone been poking at this sort of stuff?  A *loooong* time ago, I used
> to follow ReiserFS pretty closely, back when that project was a technical
> matter, as opposed to being (rather properly!) overshadowed by a murder
> investigation :-(

We use it for every customer's Openstack cloud for almost every 
openstack component. Nova, Ceph, Swift, Keystone, and MySQL are the 
major services, and each has a bcache underlay along with a hardware 
RAID controller.

It has proven to be quite a reliable (and fast) setup, and even in the 
event of a power cut we haven't lost any data.

For nova especially where users are interacting with VMs, it means a 
customer can have large amounts of storage allocated for a VM, and 
writes feel as though the whole system is running on an SSD.

Likewise for Keystone & MySQL, where in busy clouds with clustered 
MySQL, tokens can take a long time to generate, fetch, and authenticate 
without the SSD backing.

All around quite useful, just don't run it on the leading edge of GCC, 
Kernel, and OS releases!