One of the long-awaited features introduced with vSphere 5.1 was VOMA (vSphere On-disk Metadata Analyzer). This is essentially a filesystem checker for both the VMFS metadata and the LVM (Logical Volume Manager). Now, if you have an outage either at the host or storage side, you have a mechanism to verify the integrity of your filesystems once everything comes back up. This gives you peace of mind when wondering if everything is ok after the outage. There is a requirement however to have the VMFS volume quiesced when running the VOMA utility. This post will look at some possible reasons…
The advanced setting SunRPC.MaxConnPerIP defines the maximum number of unique TCP connections that can be opened for a given IP address. This is of particular interest to users of NFS. If the number of mounts to an IP address is more than SunRPC.MaxConnPerIP, then the existing connections for NFS mounts are shared with new mounts from the same IP address. Currently VMware supports a maximum of 128 unique TCP connections per ESXi host but also supports up to 256 mounts per host. So what options are available to configure ESXi hosts to allow the maximum number of NFS mounts?
This is a follow-up to my previous post on the 5.0U2. At the same time, VMware also released vCenter 5.1.0b. This post will look at the storage items which were addressed in that update, although the issues that are addressed in the storage space are relatively minor compared to the enhancements made in other areas. Note that this update is for vCenter only – there is no ESXi 5.1 update.
Hi all, Prior to the holidays, VMware released new versions of vCenter & ESXi on December 20th. There were new releases for both vSphere 5.0 & 5.1. In this post, I want to discuss release 5.0 Update 2. There were a number of notable fixes specific to storage which I wanted to highlight. I will follow-up with a look at storage enhancements in the new 5.1 release in a future post.
Welcome to the next instalment of NFS Best Practices. In this fourth and final best practice section on NFS, I asked a number of our major NAS storage partners some sizing questions. The questions basically fell into 3 different categories: Do you have a recommended NFS volume size/sweet-spot recommendation? Do you have a volume block size recommendation that should be configured on the array? Do you have a recommended number of VMs per NFS datastore? In fact, the responses from the vendors were all pretty similar. Let’s take a look at what they had to say. Maximum volume Size/Sweet Spot…
I recently received a question about the following message appearing in the VMkernel logs of an ESXi host: 2012-12-07T12:15:58.994Z cpu17:420151)ScsiDeviceIO: 6340: Could not detect setting of sitpua for device naa.xxx. Error Not supported. So what does that mean? Firstly, it isn’t anything to be greatly concerned about. SITPUA, short for Single Initiator Thin Provisioning Unit Attention, is related to Out Of Space (OOS) conditions on Thin Provisioned LUNs. To ensure that an Out Of Space (OOS) warning is sent to just one host using the affected LUN, the SITPUA bit in the Thin Provisioning Mode Page must be set to…
Welcome to part 3 of the NFS Best Practices series of posts. While part 1 looked at networking and part 2 looked at configuration options, this next post will look at interoperability with vSphere features. We are primarily interested in features which are in some way related to storage, and NFS storage in particular. While many of my regular readers will be well versed in most of these technologies, I’m hoping there will still be some items of interest. Most of the interoperability features are tried and tested with NFS, but I will try to highlight areas that might be…