Comment 3 for bug 1264029

@David, do you think backend store issue resolving/debug is a responsibility for cloud admin/operator or end user? I believe it is former, agree that? So I think in store drivers we can just write those backend storage related exceptions to Glance log only instead expose them to end user, since IMO a) those details is not valuable and make sensible to end user; and b) the exception probably can contains sensitive information, like Cloud internal deployment details and/or credentials.