Hardware.... not for the feint hearted

Dell Powervault MX3100

Had to fit a replacement RAID battery on One of These Puppies.
5 minute job I hear you say? Well not really no.
The server has 20TB storage and the full timers have been avoiding running maintenance, so when the server hangs the process is.... Hard reboot and skip the chkdsk that the Win2k8 Storage Server wants to do. JOY OF JOYS. Just happens to be a key production server...what could go wrong?

Friday....Italy v Costa Rica and I really want to see the game....phone rings in the office, can you replace the RAID Batt tonight? Full Timer at his best...Aye OK.

Anyway time slips by time to do the job.

Shutdown the server, slip the lid off, replace the batt, replace the lid, power on....crap no keyboard response, it's wanting to start chkdsk...NNNAAWWW.

Pulled the power before it started.

This link served for some inspiration Legacy Mode but no, no option for that in the BIOS. 

My colleague says "gives an option to just have the back usb ports on" we tried it and it only just worked eh!!!! Relief or what!!! Server back up without the OS causing potential data loss with data corruption caused by a chkdsk. On a server with out a trusted backup or fail over server....#£$%^& sake!!

You could see the number lock key switch off during the initial boot, so always have that on and watch it, if it goes off when windows is loading you wont be able to bypass chkdsk. Pull out the mouse as well so that the system only has to sense the keyboard, the less devices connected via USB the better.

Dell 2950

Server was not responding to RDP. Got to the server room, no display just the black screen. Luckily the server was in warranty so take a note of the tag generate the express code, and call the Dell Support. They will need a DCET report so use Rufus and make sure you have atleast a 2GB USB stick. There are more instructions for Rufus in another post on the blog.

The bad news is the PERC or RAID Batt and a Disc may be FUBAR...

All the disc LEDs were green except for one disc and it's flashing alternately Green and Orange...predicted failure. Dell will talk you through the RAID card config and, when they are happy, they will ask for a reboot to the OS.

In this case, looks like a RAID Batt and a Disc caused the fault or perhaps there was another event...not sure.

All the utils you need are in this blog, just tough it out!!

MD300 connects to a MD1000 and then to two cluster servers

Strange storage cluster issues. One server reporting that it does not have the necessary information configured in the registry. It was missing SCSI Memory Buffers, well that was one of the several issues this cluster has...

IRPstacksize sets Mem Buffers for SCSI

What Architecture?

Having to build a specialized workstation today that controls a Digital SLR camera. The PC is a workstation with an Octa Processor core and 8GB ram. So 8 processors, 8GB ram two hard discs and all I have is a Win7 32-bit install disc.....NAW!!! It's not going to happen.

Found this out on the WWW and seems to describe things quite nicely without me rabbiting on...

Win7 32bit V 64bit 

List installed Drivers
CLI And Powershell commands to see what drivers the hardware is using.

Driver Query

List USB Devices
You may have to do some tweeking of the commands but this will get you in the ball park of querying USB devices. I've put my variation on the Powershell 2.0 post.

Display USB Devices 

Dell Service Tag Numbers and Express Codes

The Dell Support number I generally use from the UK is 0844 444 3844.
And you are in to the automated phone system that takes you through options and then asks for an express service code, a what? I hear you say!!! Well just make sure you have the tag number and convert it to the service code from this link...

Tag->Express Service Code Converter
Dell Tech Direct - Online Helpdesk
PowerVault MD3xxx range Mind and use the Dell Modular Disk Configuration Utility to carve up the discs on the ISCSI storage.

PCs & Workstations

HP

Z230 HP Workstation HP Support Page Z230

Printers

HP
p2055dn firmware update
HP2015dn Debug Flowchart

Servers

Dell PowerEdge
Usually Dell want a DCET report ran on the kit that is faulty, usually best to use a USB stick and config an ISO image so the server boots off of the USB stick.

A pretty comprehensive list of servers is covered by this DCET iso download so check the model number against the list first, then refer to my post about the Dell 2950 further up the page and the post about Burning ISOs...

Check this list for a DCET ISO download   used for a faulty 2950, 1950

R720
Dell R720 RAID 5 Config training Video
R720 Support Page

Disc Storage Trays

Dell
Dell MD3000 Support Page  Graceful shutdown MD3000
Powervault-MD3260i Deployment Guide

Video Grabber Cards

Silicon Graphics
Digital imaging software and drivers

Interesting Read about Processors

Oh I was reading about performance monitoring and stuff, a phrase came up about CPU rings.....confused?
I was..... and I found this article....

CPU Rings and Things

Anyway thought it was pertinent to the stuff I was doing with the Sysinternals utils I downloaded.

Burning ISOs with Native Win7/8 Commands and GUIs

So today I have an ISO image to burn to CD. The PC I usually use with Roxio installed has been removed or the app uninstalled. I have a Disk Module upgrade to burn to ISO.....eh...what amI gonna do now....well thanks to the PC being Win7 I used the Isoburn command line tool.
Here is a good article to get you out a hole if you have no CD burning utils.

ISOburn

So baisically run a command prompt and type

Isoburn/q filepathname

Making a USB Stick a Bootable ISO to replace a DVD/CD player
Handy when the server has a CD but the ISO is over a GB...make a Bootable USB stick and change the boot options on the Server/PC boot order to boot off of the USB port...simples...

RUFUS ISO->bootable USB Util

The page can be a bit confusing, so download RUFUS and launch it.

Now in my case I have a duff server, looks like the RAID Controller is kaput. So Dell send me an ISO to run a Linux OS and from there, their DCET diagnostic util.

Select the USB device, then move down to the very bottom of the GUI

So look at the Rufus GUI, look at the "Format Options" section.
The section "create a bootable disk using" select "ISO Image"
The little CD/DVD Icon to the right is where you select the ISO Image path.

When you are under stress and duress, because a server has went U/S and every man and his dog is calling you and you have been given a new util to use....might not seem that obvious because of the strain!!

Nice little util all the same, and no need for a CD/DVD burner, just a USB stick big enough for the ISO.

Redundant Array Inexpensive Discs

RAID

Most servers use Hard Disk Virtualisation to lump several hard disks together. Once that config has been decided and actioned, the new virtual disks can be connected/presented to the server.  The server will only see the virtual disk not the individual disks.

Thought I'd take a wee note and put down what RAID configs are the most common. Thanks to SCSI hardware and software we can slice n dice big trays of hard disks anyway we want to provide greater functional scope!!

RAID was originally called Redundant Array of Inexpensive Disks it now means Redundant Array of Independent Disks.

The main goals of RAID is to provide fault tolerance by redundancy and performance through disk striping.
Striping distributes data over several hard disks and spreads the load over the hardware. Redundancy is additional information that is stored so that operations can continue in the event of a disk failure.

A RAID controller writes the data to the virtual hard disk, the hardware and protocols will distribute the data automatically across the physical disks in various manners, these are called RAID levels.

RAID 0 = block by block striping
Distributes data written to the virtual disk on to one physical disk after another. So if disk A is busy next block is written to disk B then disk C...increases performance. I suppose this can be looked at as a sequential writing of data. Increases Performance

RAID 1 = block by block mirroring
Simplest example brings two hard disks together to form a virtual disk. Data is duplicated between the disks. Provides redundancy. Increases Fault Tolerance.

RAID 2 = Hamming Code
Defunct config. A technique used to detect disk data errors by storing redundancy data as well as real data. This functionality or comparative functionality is performed by disks and controllers now so the level is defunct.

RAID 3 = Parity Data
Stores parity data and stores data of a block amongst disks. All disks are involved in  read/writes. All disk rotations on the spindle are synchronised for simultaneous access. It was recommended for sequential write/read profiles. Now less important due to modern capabilities of hard disks and hard disk cache capabilities/techniques.

RAID 4 = PARITY
Idea of  PARITY is to replace mirrored disks with a parity disk.
One of the disk out of the group of disks will be kept as a parity disk. Data will be striped across the remaining disks. In the event of failure, the Parity disk and the Data disks will combine data/parity blocks to reconstruct the original data on the replaced disk.

RAID 5 = STRIPED PARITY
The Parity blocks are distributed sequentially across all the physical disks in the virtual disk. Now if a disk fails the remaining disks will use the data and parity blocks to rebuild the data.

RAID 0+1 = 2 stage Virtual disk hierarchy
Step 1 = Raid 0 = block by block striping. Step 2 = Raid 1 = block by block mirroring amongst several virtual Raid 0 disks. So we combine the two techniques! Apply it to several Virtual Disks

RAID 10 = 2 stage Virtual disk hierarchy
Kind of the reverse of RAID 0+1... bring the physical disks together using RAID 1 mirroring. Now consolidate the virtual disks with RAID 0 stripping. Again only the second level config is presented to the server.

In both RAID 0+1 and RAID 10 the server sees only a single disk which is faster, larger and more fault tolerant than the standard physical disks.

For a more in depth look at RAID Levels check this wikipedia page.
For a good book on Storage networks and RAID I recommend this book.