The ramblings of a computer geek
Postman is a great tool for testing and using APIs, in this article, I’ll show how you can use a Global Variable within Postman to store a value for reuse in other requests. I’m using an HPE Nimble Storage (Alletra Storage) array as a example for illustrating this. The API requires that you login using … Read more
We were conducting a data centre relocation which involved moving an HPE Nimble Storage array, changing the array name and group is straight forward enough, this can be done from the GUI within the “Hardware” section. However once changed clients still see the old group name which included the old name of the array. Resolving … Read more
I was working on an issue whereby we were looking at traffic flow problem to a Dell Powerscale, attempting to identify why a particular VLAN was not able to be communicated with, we were unsure if the issue was network or storage. Luckily the Dell Powerscale includes “tcpdump”, so in this case we setup a … Read more
There are graphical tools to test and use the Dell ECS S3 interface, but everyone wants a CLI right? The below should also work for AWS S3 (with some modification) but this documentation is intended for specific use with the Dell ECS S3 endpoint to verify behaviour and perform some performance testing. The below assumes … Read more
The Dell ECS is an object based storage platform, in our case we are using it as an archive layer to our Dell PowerScale platform; where it provides a single-namespace file-system allowing “cooler” data to be pushed to the “cheaper”, slower Dell ECS storage freeing up the front-end storage for new data that is “hot” … Read more
Finding the connected clients to a Dell PowerScale storage cluster is fairly straightforward, however you should be aware that it only shows clients that have active IO (input-output) operations in flight at the time you run the command. You can still have clients connected, but are idling, so are invisible. You can also specify a … Read more
When building a new VMware ESXi host or when troubleshooting any storage issues, it can be quite laborious to test each possible path, especially when you have multiple storage arrays. The script below makes this easy, just add the HPE Nimble Storage iSCSI Discovery IP Address(es) and then the iSCSI Storage Port IP Addresses as … Read more
The array OS 5.1.x and later supports iSCSI Group Scoped Target (GST) on iSCSI arrays (this is new), previous to this it was using VST Volume Scoped Targeting. GST reduces the number of individual host connections you need to configure and manage, which saves you time and also ensures you don’t hit limitations in the … Read more
The Path Selection Policy is set for devices to determine how the ESXi host will utilise the paths to the storage, for example, you can have “Fixed” or “Round Robin” or “Most Recently Used”, you can also have storage vendor provided ones such as “NIMBLE_PSP_DIRECTED”. The scripts and commands I’ve found keep mentioning “Multipathing”, if … Read more
Running a disk test need not be complicated. Microsoft provide a cheeky little hard disk test program that can be used, you can download it from https://github.com/microsoft/diskspd. A simple run can be completed with the following command to test the hard drive performance based on the parameters entered. If you wish you can add “> … Read more