On 2021-10-24 06:48, Mladen Gogala wrote:
On 10/23/21 09:37, Laura Smith wrote:Hi Mladen,
Yes indeed, snapshots is the primary reason, closely followed by zfssend/receive.
I'm no stranger to using LVM snapshots with ext4/xfs but it requires a custom shell script to manage the whole process around backups. I feel the whole thing could well be a lot cleaner with zfs.
Thank you for the links, I will take a look.
Laura
Yes, ZFS is extremely convenient. It's a volume manager and a file system, all rolled into one, with some additiional convenient tools. However, performance is a major concern. If your application is OLTP, ZFS might be a tad too slow for your performance requirements. On the other hand, snapshots can save you a lot of time with backups, especially if you have some commercial backup capable of multiple readers. If your application is OLTP, ZFS might be a tad too slow for your performance requirements. The only way to find out is to test. The ideal tool for testing is pgio:
https://kevinclosson.net/2019/09/21/announcing-pgio-the-slob-method-for-postgresql-is-released-under-apache-2-0-and-available-at-github/For those who do not know, Kevin Closson was the technical architect who has built both Exadata and EMC XTRemIO. He is now the principal engineer of the Amazon RDS. This part is intended only for those who would tell him that "Oracle has it is not good enough" if he ever decided to post here.
Interesting subject... I'm working on a migration from PG 9.2 to PG 14 and was wondering which File System should I use. Looking at this thread, looks like I should keep using ext4.
I don't know where you have your database deployed, but in my case is in AWS EC2 instances. The way I handle backups is at the block storage level, performing EBS snapshots.
This has proven to work very well for me. I had to restore a few backups already and it always worked. The bad part is that I need to stop the database before performing the Snapshot, for data integrity, so that means that I have a hot-standby server only for these snapshots.
Lucas
