Solved How can I group two or more hard drives to create a single large volume ?

[ziomario]

like this ?

zpool attach zroot /dev/ada0 /dev/ada1

 

[Cath O'Deray]

Recall that you previously gave a partition (not an entire device) to the pool:

…
# zpool status

  pool: zroot
 state: ONLINE
config:

NAME        STATE     READ WRITE CKSUM
zroot       ONLINE       0     0     0
  ada0p4    ONLINE       0     0     0

errors: No known data errors

 

[Cath O'Deray]

so,maybe :

zpool create ssd mirror /dev/gpt/zfs0 /dev/gpt/disk1 ? is this correct ?

Now, is the intention to create a mirror?

From the opening post:

… group these SSD disks to create a single large SSD disk …

Mirroring does not enlarge a pool.

(The title is outdated – "UFS - How can I group two or more hard drives to create a single large volume ?")

 

[ziomario]

No,I don't want to create a mirror. I want to enlarge the size of ada0p4 without destroying ada0 or ada1. So. Is this correct ?

zpool attach zroot /dev/ada0p4 /dev/ada1p1

The partitions are these :

=>       40  976773088  ada0  GPT  (466G)

         40     532480     1  efi  (260M)
532520       1024     2  freebsd-boot  (512K)
533544        984        - free -  (492K)
534528    4194304     3  freebsd-swap  (2.0G)
4728832  972044288     4  freebsd-zfs  (464G)
976773120          8        - free -  (4.0K)

=>       40  976773088  ada1  GPT  (466G)

40  964689920     1  freebsd-zfs  (460G)
964689960   12083168        - free -  (5.8G)

 

[Cath O'Deray]

zpool-add.8 — OpenZFS documentation

Option -n allows you to perform a dry run.

zpool add -n zroot /dev/ada1p1

Please note, from <https://unix.stackexchange.com/a/532601/13260> (with added emphasis):

… Once you've added a vdev to a pool, you basically cannot remove it without recreating the pool from scratch. …

 

[ziomario]

… Once you've added a vdev to a pool, you basically cannot remove it without recreating the pool from scratch. …

Does it means that I should destroy the content of the two ssd disks ?

 

[Cath O'Deray]

Does it means that I should destroy the content of the two ssd disks ?

Where you have only two devices, think of it this way:

• a single-device pool can be enlarged (add a device)
• the enlarged pool can not be shrunk (what's written to the second device can not be simply 'moved' to the first).

Wrong! Sorry. See <https://forums.freebsd.org/posts/562329> below.

 

[ipsum]

No,I don't want to create a mirror. I want to enlarge

Use mirror. If you need more space, get bigger disks. Period.

 

[ziomario]

I don't want to enlarge the disk, anymore. Period.

 

[chungy]

Please note, from <https://unix.stackexchange.com/a/532601/13260> (with added emphasis):

That's no longer true as of OpenZFS 0.8 (FreeBSD 13.0 uses 2.0). You can remove basically any top-level vdev except for raidzN and draidzN, reducing the space in a pool.

 

[Cath O'Deray]

chungy thanks for correcting me!

root@mowa219-gjp4-8570p-freebsd:~ # zpool create blah /dev/da3p1
root@mowa219-gjp4-8570p-freebsd:~ # zpool status blah
  pool: blah
 state: ONLINE
config:

        NAME        STATE     READ WRITE CKSUM
        blah        ONLINE       0     0     0
          da3p1     ONLINE       0     0     0

errors: No known data errors
root@mowa219-gjp4-8570p-freebsd:~ # zpool add -n blah /dev/da4p1
would update 'blah' to the following configuration:

        blah
          da3p1
          da4p1
root@mowa219-gjp4-8570p-freebsd:~ # zpool add blah /dev/da4p1
root@mowa219-gjp4-8570p-freebsd:~ # mount | grep blah
blah on /blah (zfs, local, nfsv4acls)
root@mowa219-gjp4-8570p-freebsd:~ # touch /blah/touched
root@mowa219-gjp4-8570p-freebsd:~ # time zpool remove blah /dev/da4p1
0.000u 0.004s 0:27.76 0.0%      0+0k 0+1io 0pf+0w
root@mowa219-gjp4-8570p-freebsd:~ # file /blah/touched
/blah/touched: empty
root@mowa219-gjp4-8570p-freebsd:~ # zpool status -v blah
  pool: blah
 state: ONLINE
remove: Removal of vdev 1 copied 76K in 0h0m, completed on Sun Apr  3 20:23:55 2022
        96 memory used for removed device mappings
config:

        NAME          STATE     READ WRITE CKSUM
        blah          ONLINE       0     0     0
          da3p1       ONLINE       0     0     0

errors: No known data errors
root@mowa219-gjp4-8570p-freebsd:~ # zfs unmount blah
root@mowa219-gjp4-8570p-freebsd:~ # zpool destroy blah
root@mowa219-gjp4-8570p-freebsd:~ # zpool labelclear /dev/da3p1
root@mowa219-gjp4-8570p-freebsd:~ # zpool labelclear /dev/da4p1
root@mowa219-gjp4-8570p-freebsd:~ #