Increasing cache pool with different size disk


Recommended Posts

I'm on 6.5.3 and run a two disk (SSD) btrfs RAID1 cache pool. One disk is 525GB and one is 1TB.

 

My question is what is my pool size (in terms of how much data I can store on it)? My guess is that with the two disks I have, and if I'm using RAID 1, my pool size is actually 525GB. I'm thinking of increasing the size of my cache pool, and I'd like to replace the smaller drive with a 1TB drive. Will that increase my pool size to 1TB? I read that btrfs also stores some metadata: does that take up a lot of space?

Link to comment
5 hours ago, sonofdbn said:

my pool size is actually 525GB

Correct.

 

5 hours ago, sonofdbn said:

I'm thinking of increasing the size of my cache pool, and I'd like to replace the smaller drive with a 1TB drive. Will that increase my pool size to 1TB?

Yes.

 

5 hours ago, sonofdbn said:

I read that btrfs also stores some metadata: does that take up a lot of space?

Every filesystem uses metadata, it usually takes a very small space compared to data, but it varies with the number of files, snapshots, etc, for 1TB cache I would say usual metadata size is around 5/10GB, you can check actual size with:

 

btrfs fi usage -T /mnt/cache

 

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.