Replacing a Device in a ZFS Storage Pool After you have determined that a device can be replaced, use the zpool replace command to replace the device. If you are replacing the damaged device with different device, use syntax similar to the following: # zpool replace tank c1t1d0 c2t0d0 This command migrates data to the new device from the damaged device or […]

ZFS: PRACTICING FAILURES ON VIRTUAL HARDWARE Published by Jim Salter // May 16th, 2016 I always used to sweat, and sweat bullets, when it came time to replace a failed disk in ZFS. It happened infrequently enough that I never did remember the syntax quite right in between issues, and the last thing you want to do with production hardware […]

Reshuffling pool storage on the fly If you’re new here: Sanoid is an open-source storage management project, built on top of the OpenZFSfilesystem and Linux KVM hypervisor, with the aim of providing affordable, open source, enterprise-class hyperconverged infrastructure. Most of what we’re talking about today boils down to “managing ZFS storage” – although Sanoid’s replication management tool Syncoid does make […]

Latency and Throughput as key components of network performance We have recently added another transit feed to our New York PoP, with a declared aim to bring down latency between London and New York to sub 70ms. We are more than happy to be able to state that current latencies between London Telehouse and New York are now around 67ms. An update to […]

Diagnosing Network Speed with Iperf Linux systems administrators and network administrators often find diagnosing network speed degradation complicated, as there are very few tools available to diagnose these issues. Iperf is a command-line tool used in the diagnostics of network speed issues. Iperf measures the maximum network throughput a server can handle. It is particularly useful when experiencing network […]

How to Convert a Stripe into a Mirror in FreeNAS Ideally, with FreeNAS, if you plan on using mirrored drives, you should start directly with 2 physical drives. This holds for every combination of drives actually, because modifying existing vdevs is not allowed (you can only add new vdevs to an existing zpool). The only exception consists in converting a striped vdev into a […]

Converting a ZFS pool to be mirrored So, the ZFS syntax is quite different to that of SVM which can lead to confusion. Ben Rockwood does a good job of explaning the difference, but does not show how to convert an un-mirrored ZFS pool into mirrored one. So, here’s how to do it o We start with a pool called realzfs […]

ZFS Cheatsheet This is a quick and dirty cheatsheet on Sun’s ZFS Directories and Files error messages /var/adm/messages console States DEGRADED One or more top-level devices is in the degraded state because they have become offline. Sufficient replicas exist to keep functioning FAULTED One or more top-level devices is in the faulted state because they have […]

From 32 to 2 ports: Ideal SATA/SAS Controllers for ZFS & Linux MD RAID I need a lot of reliable and cheap storage space (media collection, backups). Hardware RAID tends to be expensive and clunky. I recognize quite a few advantages in ZFS on Solaris/FreeBSD, and Linux MD RAID: Performance. In many cases they are as fast as hardware RAID, and sometimes faster because the OS is aware […]