3 ms·
Doesn't a BBU Raid controllers largely address the power loss concern? And, I always thought BBU Raid controllers were just absolute common sense for any seriou
by latch 8y ago
Doesn't a BBU Raid controllers largely address the power loss concern? And, I always thought BBU Raid controllers were just absolute common sense for any serious database (until everyone went cloud and suddenly basics like dual network card, dual PSU and raid controllers didn't fit Amazon's desire to sell complexity).
- singron 8y agoWithout fsync, the dirty page can sit in RAM and not even be sent to the disk, so a battery backup for the disk wouldn't solve data loss.
- latch 8y agoRight..but you leave fsync on in this case, no? This might be incompatible with the locking required by this server-process edition though (I guess, no clue). But more generally speaking, fsync=on with a proper raid controller gives massive performance boost (like orders of magnitude) while being relatively resilient to power loss.
- nh2 8y agoWell, data will be lost if anything below the OS buffer cache crashes (source http://sqlite.1065341.n5.nabble.com/How-dangerous-is-PRAGMA-Synchronous-OFF-tp4250p4256.html http://sqlite.1065341.n5.nabble.com/How-dangerous-is-PRAGMA-...). The BBU protects from power loss of the HDs, but not power loss or general failure of the mainboard or any other important component. PAlso BBUs can run out of battery so a flash backed BBU is generally recommended.