Hi all
I'd like to set up a server with 8 3TB disks as a zfs storage pool. Currently I am testing the setup in VMware, as the hardware is not finished yet. I'd like to use GPT labeled partitions for the zpool.
First I initialized the storage disks with GPT (da0 contains the OS partitions):
...
Then I created 4K aligned partitions on all drives
...
If I now create a zpool like so
it seems the partitions are not 4k aligned after all
Am I doing anything wrong?
If I additionally use gnop
and then create the pool with
I get an ashift of 12.
But why is that necessary? Or should I ignore ashift? Or may this be a problem only in VMware?
Thanks in advance for any insights, I'd like to understand what is going on.
Herbert
I'd like to set up a server with 8 3TB disks as a zfs storage pool. Currently I am testing the setup in VMware, as the hardware is not finished yet. I'd like to use GPT labeled partitions for the zpool.
First I initialized the storage disks with GPT (da0 contains the OS partitions):
# gpart create -s GPT /dev/da1
...
# gpart create -s GPT /dev/da8
Then I created 4K aligned partitions on all drives
# gpart add -t freebsd-zfs -a 4k -l storage1 /dev/da1
...
# gpart add -t freebsd-zfs -a 4k -l storage8 /dev/da8
If I now create a zpool like so
# zpool create tank mirror gpt/storage1 gpt/storage2
it seems the partitions are not 4k aligned after all
# zdb | grep ashift
ashift: 9
Am I doing anything wrong?
If I additionally use gnop
# gnop -S 4096 /dev/gpt/storage1
and then create the pool with
# zpool create tank mirror gpt/storage1.nop gpt/storage2.nop
I get an ashift of 12.
But why is that necessary? Or should I ignore ashift? Or may this be a problem only in VMware?
Thanks in advance for any insights, I'd like to understand what is going on.
Herbert