DATAPUISTOKEMISTI

 I wanted to add some redundancy by mirroring disk. So I did it. Notice "-s" in zpool attach command so resilvering is done sequentially.

So you screwed up and created zpool using /dev/sdb instead of /dev/disk/by-id/ata-* as a device? Then you tried to fix it and ended up with cryptic wwn- as device name. Here's dirty solution. Make sure to run those commands right after each other. Otherwise it will get imported back with wrong device names automatically -- before you have time to do it with correct names.

Dunno how this will end up as I did again mistake of digging up one of those Wyse Z90D7 terminals from junk pile. This time my idea is to use it for NAS after upgrading RAM from 2GB to 6GB and adding two 1TB 2.5" USB3 disks. Wyse being fanless and with host powered disks this should be decent combo. Then add FreeNAS 9.2 and ZFS with snapshots. Snapshots are mandatory feature as I'm sending this to friend of mine for christmas present. He's one of those who insist on installing every virus and cryptolocker he can find. With data backed up to NAS and protected by daily snapshots recovery is much easier than ever before. With assumption that he'll save important data to network drive which will then probably corrupt it all due me using inappropriate hardware...

Lowest budget backups for your free VMware ESXi hypervisor.

My original plan was to boot from ZFS, but combining it with encryption and especially with mirrored disks turned out to be too troublesome. Yes, I did get it working and booting, but resulting configuration required manual fixing each time new kernel was installed. And don't even think about doing upgrade to next Ubuntu version.

Intel Core i5-2400, 4GB RAM, 11 x Seagate 3TB USB hard disks connected via 4 x D-Link USB3 hubs to StarTech PEXUSB3S400 PCIe card. Ubuntu 12.04 with ZFS 0.6.1. Disks were configured as RAID-Z3 (triple parity). write: 137438953472 bytes (137 GB) copied, 250.822 s, 548 MB/s read:  137438953472 bytes (137 GB) copied, 197.451 s, 696 MB/s

While burn-in testing my new USB 3.0 ZFS RAID array on Ubuntu 12.04.1 I wanted to fill disks with random data. Not zeroes from /dev/zero, but random data to catch any flakey disks or USB cables. Well it quickly turned out that reading from urandom was slowing process down a lot. Since quality of randomness doesn't matter much in this case frandom was easy solution.