I’ve written posts in the past regarding LUN masking on a storage array, but it is possible to mask a path directly from your vSphere environment. I feel that if at all possible the masking should be handled at array level because the array is closest to the disk. Let’s face it, if vSphere shouldn’t see a LUN for one reason or another, then why is the array presenting it in the first place? ...
I recently got my hands on a pair of HP P4300s in the lab and wanted to see how the performance was with Network RAID. One of the most read posts on this site is on Understanding RAID Penalty and I was curious to see how Network RAID played into this equation. Basic Setup I have 2 HP P4300s, each with eight 15k SAS drives in a RAID 5 configuration. This means that I should have a total of 1400 RAW IOPS (8 disks * 175 IOPS) on each lefthand node. Since I have 2 of them, I’m calculating 2800 RAW IOPS. In order to get some real world functional IOPS, we’ll assume that we have 50% Reads and 50% Writes, and don’t forget to take out the RAID Penalty for the RAID 5. Let’s plug this into our Functional IOPS equation to get: ...
I have been recently thrown into the world of HP Storage, and have been trying to learn all of the storage techniques that are in the HP product line. I noticed that I couldn’t find anything that really did a compare and contrast of each of the products so I started to put one together. Anything I couldn’t understand, I asked a great guy named Calvin Zito (@hpstorageguy) to give me a hand with. He was more than gracious so follow him on Twitter. ...
I was recently helping out a company attempt to upgrade their Netapp Filer from OnTap 7.3 over to Data OnTap 8. We ran the Netapp Upgrade advisor and got to a section that wanted us to run the AggrSpaceCheck tool to make sure that the aggregates had sufficient space available. Normally, I skip this step because I usually have plenty of space available, but in this particular case, some of the aggregates were already 99% full. Since we didn’t want to have a serious failure during our upgrade we decided to error on the side of caution (and best practices) and run the AggrSpaceCheck tool. ...
Netapp has released their vStorage APIs for Storage Awareness (VASA) provider 1.0 to their support site. http://support.netapp.com If you’re not that familiar with the VASA concept, this article should explain what it is and how it’s used in regards to VMware vSphere 5. What is VASA? VASA Providers collect information about your storage systems and present that information to vSphere. In previous versions of vSphere, an administrator might need to keep track of hisher datastores in a spreadsheet or have a naming convention that showed the properties of an individual datastore. For example, if your storage system had both SSD and Sata disks, the Datastore might be named VMFS01_SSD or something similar. ...
We’re probably all aware of the benefits of clustering things like SQL Server in order to provide highly available data. But shared storage clustering has some drawbacks on VMware ESXi clusters such as not being able to vMotion. • Database Mirroring – SQL Server database mirrors utilize a non-shared storage availability solution, using built-in SQL Server replication technology to create and maintain one or more copies of each database on other SQL Servers in the environment. SQL Server database mirrors provide application-aware availability, and the lack of a quorum disk makes this a VMware-friendly solution, allowing the full use of vMotion, DRS, and HA. ...
One of my most frequently read articles is on how to use MBRAlign to align your virtual machine disks on Netapp storage. Well, after Netapp has released their new Virtual Storage Console (VSC4) the tedious task of using MBRAlign might be eased for some admins. Optimization and Migration The new VSC4 console for vSphere has a new tab called Optimization and Migration. Here you are able to scan all or some of your datastores to check the alignment of your virtual machines. The scan manager can even be set on a schedule so that changes to the datastore will be recognized. ...
Determining which type of RAID to use when building a storage solution will largely depend on two things; capacity and performance. Performance is the topic of this post. We measure disk performance in IOPS or Input/Output per second. One read request or one write request = 1 IO. Each disk in you storage system can provide a certain amount of IO based off of the rotational speed, average latency and average seek time. I’ve listed some averages for each type of disk below. ...
Zoning and Lun Masking are often confused for each other, probably because both of them are used to restrict access to storage. They should both be used to secure the storage network and reduce unnecessary traffic. Zoning If you want to specify only certain hosts from accessing a storage device then you would want to setup zoning. For instance, in the example below, you can see that the two servers on the right can access three of the four storage devices, whereas the two on the left can only access two of the SANs. This configuration is done on the Fibre Channel switch. iSCSI, NFS, and FCoE can also be segmented, but they would use typical TCPIP segmentation methods like setting up a VLAN. ...
It’s important to understand how VMware ESXi servers handle connections to their associated storage arrays. If we look specifically with fibre channel fabrics, we have several multipathing options to be considered. There are three path selection policy (PSP) plugins that VMware uses natively to determine the I/O channel that data will travel over to the storage device. Fixed Path Most Recently Used (MRU) Round Robin (RR) Let’s look at some examples of the three PSPs we’ve mentioned and how they behave. The definitions come from the vSphere 5 storage guide found below. ...