3 ms·
Are EBS snapshots not block-level atomic? In theory you should get a PITR image without stopping anything, assuming that: 1) The file system correctly orders o
by nupark2 15y ago
Are EBS snapshots not block-level atomic? In theory you should get a PITR image without stopping anything, assuming that:
1) The file system correctly orders or journals operations (I'm not familiar with XFS, but this is the case with FFS2/FreeBSD, ZFS, ext3/4 journaling, etc).
2) The database system correctly orders or journals operations, and properly fsync(s) to disk (which postgreSQL does)
Of course, there's no harm to an abundance of caution with something like this.
- mikeyk 15y agoThey are, but we software-RAID our EBS drives to get better write throughput, and we put the Write-Ahead Logs (WALs) on a different RAID from the main database, so when you have both of those going on, you need something else to atomically snapshot our PG databases.