filestore xattr use omap = true
At the core standup yesterday we talked about a really nasty bug where data loss can occur if filestore xattr use omap is not enabled with RGW. A fix is being worked on now for master. In dumpling/ice we are going to enable filestore xattr user omap by default, but we probably need to change the docs to warn people they shouldn't set it to be disabled unless they absolutely know they aren't going to use RGW (and don't need EXT4).
Right now the docs say:
"Use object map for XATTRS. Set to true for ext4 file systems."
I'm not sure if there are other instances where we make similar statements, but we should probably provide at a minimum a warning.
#1 Updated by David Zafman over 9 years ago
The change for bug 6143 removed the configuration variable "filestore_xattr_use_omap" The new behavior is just like it were set to true. So the documentation can just remove any mention of that setting. We should create a new tracker if we want to add back this config var.
#2 Updated by Florian Haas over 9 years ago
David Zafman wrote:
The change for bug 6143 removed the configuration variable "filestore_xattr_use_omap" The new behavior is just like it were set to true. So the documentation can just remove any mention of that setting.
Not so much, because that fix was never backported to Dumpling. So for anyone on Dumpling or older, enabling filestore xattr use omap is rather crucial. #6143 has been updated to reflect the missing backport (actually, the missing default flip).
#5 Updated by David Zafman over 9 years ago
Let's see how we (Sage) decide to resolve #7404. I've created a pull request to backport my 6143 change completely. So that would NOT be just flipping the default. One reason for doing it that way is that it will take additional code to allow you to change the setting from true back to false.