Adding two new drives (SSD) to an existing ZFS system

I haven’t tested this yet, but I’ve installed the hardware. The real test will come after a reboot and actual use of the new drives.

NOTE: Although this claims to be creating a new ZIL (SLOG) do not believe it. In fact, stop reading right here. There is nothing of use below.

What will they be used for?

These drives are intended for ZIL (the ZFS Intent Log). This can speed up writes. These are 30GB HDD, rather inexpensive. They might also be useful for my PostgreSQL database. It could even host parts of my development environment.

I added two new SSD to a server which has been running for nearly two years. Here is how I did that.

I am using FreeBSD 9 and the disks are ada0 and ada1.

Create the partitions

In this case, I am using all the disk, because they will be used exclusively for storage, and will not be bootable.

# gpart create -s GPT ada0
ada0 created
# gpart create -s GPT ada1
ada1 created
# gpart add -t freebsd-zfs -l ssd0 ada0
ada0p1 added
# gpart add -t freebsd-zfs -l ssd1 ada1
ada1p1 added

This labeled each device as ssd0 and ssd1. Those labels are used in the next step.

Creating the zpool

# zpool create -f ssd mirror /dev/gpt/ssd0 /dev/gpt/ssd1

And here we are:

# zpool list
ssd     29.8G    95K  29.7G     0%  1.00x  ONLINE  -
system  16.2T  5.16T  11.1T    31%  1.00x  ONLINE  -

What’s the status?

# zpool status
  pool: ssd
 state: ONLINE
  scan: none requested

	ssd           ONLINE       0     0     0
	  mirror-0    ONLINE       0     0     0
	    gpt/ssd0  ONLINE       0     0     0
	    gpt/ssd1  ONLINE       0     0     0

errors: No known data errors

  pool: system
 state: ONLINE
status: Some supported features are not enabled on the pool. The pool can
	still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
	the pool may no longer be accessible by software that does not support
	the features. See zpool-features(7) for details.
  scan: scrub in progress since Thu Dec 25 04:16:06 2014
        3.33T scanned out of 5.14T at 86.8M/s, 6h4m to go
        0 repaired, 64.84% done

	system         ONLINE       0     0     0
	  raidz2-0     ONLINE       0     0     0
	    gpt/disk0  ONLINE       0     0     0
	    gpt/disk1  ONLINE       0     0     0
	    gpt/disk2  ONLINE       0     0     0
	    gpt/disk3  ONLINE       0     0     0
	    gpt/disk4  ONLINE       0     0     0
	    gpt/disk5  ONLINE       0     0     0

errors: No known data errors

That status message refers to the existing zpool and the next post will deal with that upgrade.

The scrub is coincidentally and not related to recent actions.

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