Create new pool and replicate from backup

[adrianwi]

I know depasseg has a similar thread https://forums.freenas.org/index.php?threads/best-method-for-upgrading-pool.38962/#post-238554 but I thought I'd ask for some thoughts on my specific task.

I have 2 FreeNAS machines. My production machine (as per signature) has 7x4TB drives in RAIDZ2 and is approaching 75%. My backup machine has 5x4TB drives in a stripe and is about 70% full.

The production machine (APEpool1) is replicated to the backup machine (APEpool2) every night and each dataset has a a number of periodic snapshots (kept weekly, monthly and 6 monthly) and a replication task.

I was planning on destroying the pool APEpool1 to add another 4TB drive and create a new pool with 8x4TB in RAISZ2.

My plan goes something like this:

• Check APEpool2 datasets to check everything has replicated successfully from APEpool1 (the sizes are pretty similar, but in most cases not identical which I was hoping was down to the compression?)
• Destroy APEpool 1 and add new disk
• Create APEpool 1 with 8x4 disks
• Create replication tasks on APEpool2 to APEpool1 (will I be able to use the snapshots that already exist from APEpool1, or will have have to create new periodic snapshots on APEpool2?)
• Check APEpool 1 datasets and check everything has replicated from APEpool2
• Set Jail configuration root path to APEpool1/jails

The last line is the bit making me worry the most, as I'm hoping this will then display a list of the jails in the appropriate tab and I will be able to simply start them up. Having to recreate them will be a royal PITA! Once APEpool1 is back up and running, recreate the periodic snapshots and replication tasks back to APEpool2. Hoping that will keep me going for another year or two by which time I'll be looking to replace the 4TB drives with something bigger.

Thoughts on where this might cause me problems, or any tips and tricks would be much appreciated.

 

[depasseg]

That's what I did, and all my jails came back fine (although you might have to reboot or detach/reattach the new APEpool1). I'd recommend making a system config backup before you destroy APEpool1. When you destroy it, you will lose snapshot, replication and share settings associated with it. So after you replicate back, you can import the system config and have you snapshots/replication and shares quickly working again. And if you care about the reporting statistics, you should move the system dataset to the USB (or another pool) before you destroy. You can move it back after the new APEpool1 is back online.

 

[Robert Trevellyan]

Thoughts on where this might cause me problems

If you lose any single disk in your backup box during this process, you'll lose all your data. Consider buying 2 more 4TB drives, one to expand your main pool and one to turn your backup pool into a 6-drive RAIDZ1.