Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
drbd at bobich.net wrote: > On Thu, 14 Feb 2008, Tomasz Chmielewski wrote: > I disagree. It's not a solution because syncing the FS isn't sufficient. > With LVM you still get the FS level consistency as it is at the time of > the snapshot. The problem is that applications like DBs maintain their > internal buffers and caches, and these will not necessarily be > consistent with the data on disk, FS freeze or not. Syncing the FS _is_ sufficient. That is why DBMS implement write ahead logs. Recovering from a snapshot is the same as recovering from a power failure. And if a DBMS can't do that, it doesn't conform to ACID, and no one serious would use it. There is no serious DBMS out there that is unhappy with FS snapshots, even MySQL / innoDB is fine. In case of XFS it's actually better than a power failure, both meta data and data is flushed, as well as an umount record written. Have you ever tried running a DBMS on copyfs? There is a reason why no one is doing that. First there is no reason to do it, second performance is unacceptable. -- Best regards, H.D.