Adding special mirror with different disk than pool's disks

OpenZFS
1

Hello,

i have a ZFS pool with:

6x 4TB SSD

	Logical  Sector size:                   512 bytes [ Supported: 512 ]
	Physical Sector size:                  4096 bytes

For now, everything works like a charm.

I want to add special mirror for metadata storage to speedup the pool ( i have ~50M of files ),

so, i want to re-use 500GB SSD disk i have.

Logical  Sector size:                   512 bytes [ Supported: 512 ]
Physical Sector size:                  4096 bytes

However, i have

[08:36:58] [root@server ~]# zpool add   backups special mirror /dev/sdb4 /dev/sde4
cannot add to 'backups': adding devices with different physical sector sizes is not allowed

My current pool

[08:37:16] [root@server ~]# zdb -C backups | grep -E 'ashift|vdev_type|path'
                ashift: 9

Do you have an idea ?

I tried with ashift=9 and ashift=12, but i hve the same error.

Thanks !

2

I have 128GB ram, so i configured this

options zfs zfs_arc_max=103079215104
options zfs zfs_arc_min=85899345920
options zfs zfs_arc_meta_limit=85899345920
options zfs zfs_arc_meta_min=64424509440

It should permit to store inodes, files list etc.. in the ARC ram, i will see if it’s enought for all.