Bilal Ahmed, Author at

Dell Compellent and SCSI UNMAP

May 15, 2016 Bilal Ahmed 0

Dead space reclamation (SCSI UNMAP) Basically the UNMAP command is used when you have Thin Provisioned LUNs, you run it against VMFS 5 datastores, hopefully freeing up some space. This will allow the hosts to correctly report the list of deleted blocks on the datastore to the array. It basically is a space reclamation feature that helps reclaim space left by deleted data. The main reasons you would want to run this on all Thin Provisioned LUNs, would be because of: Storage vMotion, VM snapshots and VM deletion. As even though the VM/Snapshot etc has been deleted it doesn’t mean the array is aware of this! It was disabled in ESXi 5.0, due to various issues and enabled in 5.1 by using […]

Lost connectivity to the device mpx.vmhba32 ERROR

May 11, 2016 Bilal Ahmed 0

So I had this wonderful error happen to me recently. I am in the process of migrating the Management IPs from one network to another on all the hosts in the environment. It is part of a bigger plan to migrate everything including the vCenter components to a new IP range ( I am not looking forward to that esp since this is a 5.1 environment!). I did that and updated DNS, flushed the DNS caches on my machine and on the PRTG probes etc. The host came back up fine, but when it rejoined vCenter it had this wonderful error message: Lost connectivity to the device mpx.vmhba32:C0:T0:L0 backing the boot filesystem /vmfs/devices/disk/mpx.vmhba32:C0:T0:L0. As a result, host configuration changes will […]

Setting a persistant scratch location on a ESXi host

May 11, 2016 Bilal Ahmed 0

I noticed one of the hosts had a warning saying that: So basically I did what this KB article said: VMware KB article I had a look at another host, and had a look at the Advanced Settings value for: ScratchConfig.ConfiguredScratchLocation It showed a VMFS volumes /vmfs/volumes/UUID/Scratch folder for that host. So it showed me the UUID such as this: vmfs/volumes/51dda02d-fade5016-8a08-005056171889/HOSTNAME So it looked like there was a folder on this LUN every host! So since I am new to this environment I had to find a way to translate the UUID to the name of the actual SAN datastore being used. I did this by using the: esxcli storage filesystyem list | grep UUID This gave me the actual […]

Setting up a HP StorageWorks P2000 G3 and a EMC CX4-120

May 6, 2016 Bilal Ahmed 0

So we decided to re-provision some old storage kit we had lying around. We found that we had an old StorageWorks P2000 G3 and a EMC CX4-120. We decided to attach them to a HP DL380 G6 we had spare, and fit that server with 2x8Gb HBAs and 2xSAS cards. The HBAs to attach to the EMC and the SAS cards to attach to the HP. So I installed 2012 on the physical box, got it all up and running. I noticed an issue with the SAS cards that on boot sometimes they wouldn't initialize and they would have the yellow exclamation mark next to them in the Windows device manager, and I found that by just disabling and re-enabling […]

Passed VCAP5-DCD!!! v5.5 Exam Experience/Review

May 5, 2016 Bilal Ahmed 0

I took VCAP5-DCD 5.5 and passed with a 334!!! I have to say both VCAP exams are the only 2 I have ever done where I have had no idea whether I was in with a shot of passing once I clicked the finish button! I want to thank everyone in the Google+ DCD group, as seriously without the group and the experiences of everyone in it, I don’t think I would have passed . It is a tough exam, I have found design a tough thing to do, there are so many what ifs and it depends. I have spent long periods of time very confused…but they say confusion comes before understanding… …..and that is true! My journey to the DCD […]

vSphere Design Workshop v5.5 Review

May 2, 2016 Bilal Ahmed 0

So after doing all that studying, I thought it was time to delve deeper into the design side of things! Coming with very little design knowledge, I decided to take the official design course. I did a lot of research and read a lot of reviews with regards to the course, as I would be paying for it myself. Point to note every course I have ever been on……I HAVE PAID FOR MYSELF. All the studying has been in my own time, the best any company has done for me is pay for my exam. So when people tell me they don’t have the time, or cant afford it, I call bullshit! It takes sacrifice, all this effort I have put […]

Resetting a lost ESXi 5.1 root password on a Dell R710

April 15, 2016 Bilal Ahmed 0

So I found out that no one new the root password to a host in one of the clusters. So I tried various things to no avail: Had a look in the documentation for it (What it was supposed to be, it wasn’t that) Checked if the keyboard layout was correct (it was) I tried the Host Profiles trick to reset the password to what you want (it didn’t work for some strange reason). It took the profile and applied it and everything, but the password persisted! Reset root using host profiles Reset root using host profile in Web Client Tried 2 Linux live cds and it turns out none of them work with Dell servers in general, due to driver […]

So I passed my VCAP5-DCA back in January 2015!

February 11, 2016 Bilal Ahmed 0

Here is a breakdown of how it went and what I did, so if anyone else is considering doing it here ya go! At the time I worked for a Managed Services/DR/BC company so we had a lot of kit sat idle at times, which was free to use for labs! I had a lab setup at work as follows: 5x DL380 g7 in 2 clusters 14TB IBM DS4700 FC SAN 8TB IBM DS3300 iSCSI SAN Some local storage in each server Windows Server 2008 which ran vCenter and the client ( I installed teamviewer on this pc so I could login from anywhere on my laptop). No AD setup. I had vmotion and iSCSI traffic in one vlan and FT […]