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860lacov

Member

Registered: 2020-05-02

Posts: 497

[SOLVED] Which is the default space cache version in BTRFS?

I checked:
BTRFS(5)
and
Btrfs administration

And it seems that v1 is the default option.
There is also:

On very large filesystems (many terabytes) and certain workloads, the performance of the v1 space cache may degrade drastically. The v2 implementation, which adds a new b-tree called the free space tree, addresses this issue.

My hard disk is 1 TB ssd drive. Home workloads.

I reformatted in recently with mkfs.btrfs with default options.
I used genfstab.

In my I have fstab:

/               btrfs           rw,noatime,compress=zstd:3,ssd,space_cache=v2,commit=120,subvol=@   0 0

So if v1 is the default, then why it was formatted and mounted with v2?

And the most important thing.
Should I even care?

Last edited by 860lacov (2023-02-23 21:28:05)

loqs

Member

Registered: 2014-03-06

Posts: 18,962

Re: [SOLVED] Which is the default space cache version in BTRFS?

Dated documentation https://github.com/kdave/btrfs-progs/co … a271367507
genfstab uses a mounts current mount options when generating an fstab entry.