Continuing from our last post on scrubbing and resilvering data in zpools, we move on to changing properties in the zpool. Motivation With ext4, and many filesystems in GNU/Linux, we have a way for tuning various flags in the filesystem. Things like setting labels, default mount options, and other tunables. With ZFS, it's no different, […]
Standard Validation In GNU/Linux, we have a number of filesystem checking utilities for verifying data integrity on the disk. This is done through the "fsck" utility. However, it has a couple major drawbacks. First, you must fsck the disk offline if you are intending on fixing data errors. This means downtime. So, you must use […]
Our previous post finished our discussion about VDEVs by going into great detail about the ZFS ARC. Here, we'll continue our discussion about ZFS storage pools, how to migrate them across systems by exporting and importing the pools, recovering from destroyed pools, and how to upgrade your storage pool to the latest version. Motivation As […]
Our continuation in the ZFS Administration series continues with another zpool VDEV call the Adjustable Replacement Cache, or ARC for short. Our previous post discussed the ZFS Intent Log, or ZIL and the Separate Intent Logging Device, or SLOG. Traditional Caches Caching mechanisms on Linux and other operating systems use what is called a Least […]
The previous post about using ZFS with GNU/Linux concerned covering the three RAIDZ virtual devices (VDEVs). This post will cover another VDEV- the ZFS Intent Log, or the ZIL. Terminology Before we can begin, we need to get a few terms out of the way that seem to be confusing people on forums, blog posts, […]
The previous post introduced readers to the concept of VDEVs with ZFS. This post continues the topic discusing the RAIDZ VDEVs in great detail. Standards Parity RAID To understand RAIDZ, you first need to understand parity-based RAID levels, such as RAID-5 and RAID-6. Let's discuss the standard RAID-5 layout. You need a minimum of 3 […]
So, I've blogged a few times randomly about getting ZFS on GNU/Linux, and it's been a hit. I've had plenty of requests for blogging more. So, this will be the first in a long series of posts about how you can administer your ZFS filesystems and pools. You should start first by reading how to […]
I just setup an SSD ZFS Intent Log, and the performance improvements have been massive. So much so, I need to blog about it. But first, I need to give you some background. I'm running a 2-node KVM hypervisor cluster replicating the VM images over GlusterFS (eventually over RDMA on a DDR InfiniBand link). One […]
UPDATE (May 06, 2012): I apologize for mentioning it supports encryption. Pool version 28 is the latest source that the Free Software community has. Encryption was not added until pool version 30. So, encryption is not supported natively with the ZFS on Linux project. However, you can use LUKS containers underneath, or you can use […]
