As an experiment, I created a small (8GB) ZFS volume in a mirror configuration using two 8GB USB Flash drives.<\/p>\n
The purpose was to put “small, but really important things” on this storage system.<\/p>\n
It actually ended up being two discrete pieces of work. First, setting up a VirtualBox FreeNas 9 image with “USB passthrough”. Second, running the FreeNas\/BSD commands to create the volume by hand, since FreeNas insists on using 2G (fixed) per disk when it creates volumes. 2GB of 1000GB isn’t even a drip; 2GB of 8GB is significant.<\/p>\n
So, second things first: creating the partition and volume and getting FreeNas to acknowledge it.<\/p>\n
Once you know the two devices in FreeNas (for me it was \/dev\/ada1 and \/dev\/ada2), you can run these commands:<\/p>\n
gpart create -s gpt \/dev\/ada1\n\ngpart add -i 1 -t freebsd-zfs \/dev\/ada1\n# now run ls -l \/dev\/gptid, make note of the new entry,\n# e.g. d50a7a3b-aeb0-11e6-86a2-080027bed2b8\n\ngpart add -i 1 -t freebsd-zfs \/dev\/ada2\n# make note of that gptid too, \n# e.g. e9c860e9-aeb0-11e6-86a2-080027bed2b8\n<\/pre>\nSince my two USB drives were not exactly the same (7.4G versus 7.2G), the zpool create required the “-f” flag:<\/p>\n
\nzpool create -f usb8 mirror \/dev\/gptid\/d50a7a3b-aeb0-11e6-86a2-080027bed2b8 \/dev\/gptid\/e9c860e9-aeb0-11e6-86a2-080027bed2b8\n\nzpool status\n pool: usb8\n state: ONLINE \n scan: none requested \nconfig: \n NAME STATE READ WRITE CKSUM \n usb8 ONLINE 0 0 0 \n mirror-0 ONLINE 0 0 0 \n gptid\/d50a7a3b-aeb0-11e6-86a2-080027bed2b8 ONLINE 0 0 0 \n gptid\/e9c860e9-aeb0-11e6-86a2-080027bed2b8 ONLINE 0 0 0 <\/pre>\nThen, to get FreeNas to acknowledge it:<\/p>\n
\nzpool export usb8\n<\/pre>\nFinally, in the FreeNas GUI, run “Import Volume”, no encryption, selecting the volume name in the drop-down list. Under “Disks”, you should see two “7.xGiB” entries, not the “5.xGiB” the the 2GB swap partition would have given you.<\/p>\n
If you didn’t make note of the gptid as you created the partitions, you can run<\/p>\n
gpart list<\/pre>\nAnd look for the “Name: ada1p1” entry to get the “rawuuid” value to use with \/dev\/gptid\/hxhxhx….<\/p>\n
Using the gptid\/rawuuid, instead of \/dev\/adaX, is a good idea in general. In this particular case, remember that the device is actually a VirtualBox-created “Disk”, with a VirtualBox serial number, and a VirtualBox gptid.<\/p>\n
See the next post on how the “pass-through” was created in VirtualBox.<\/p>\n","protected":false},"excerpt":{"rendered":"
As an experiment, I created a small (8GB) ZFS volume in a mirror configuration using two 8GB USB Flash drives. The purpose was to put “small, but really important things” on this storage system. It actually ended up being two … Continue reading