Showing posts with label Technology. Show all posts
Showing posts with label Technology. Show all posts

Wednesday, September 12, 2012

Dell certification notes

These are notes that i made to help me with passing the online Dell test for servers and desktops.  It's gibberish to most people but helped me with passing the tests.  Everything in red is referencing a question that I had to answer in the actual test.



SERVERS
Solution that provides consolidated consistent way to monitor, configure, update and manage servers = OMSA Open Manage Server Assistant
SAS = NOT Leverages SCSI command set, supports multiple drives on channel, shares throughput bandwidth
View logs related to DRAM failure = DSET, OpenManage Server Administrator
Drives that are complete and consistent = Controller guide, Header guide, Time-stamp, Sequence number
Items detected and communicated using DRAC = Temp, Voltage, Fan Speeds
Hot spare = used to replace failed drive in redundant array
Clear non-BIOS errors from LCD = clear SEL
LCD display during POST = NOT BIOS version, date/time
Components in RAID that can contain firmware = PERC, backplane, HD
32 bit diagnostics CD can create = USB, Disk, HDD image
Valid color coded message displayed on LCD = alert state – amber
Perform global re-scan of storage drives = OpenManage Server Administrator
Perform HD self tests while server running = NOT OpenManage, 32 bit diag
Dell diagnostics operating within the OS = NOT DSET, 32 bit, MpMemory tests
If RAID drive goes offline, 1st step = Attempt to rebuild the drive
Available in PERC BIOS = NOT modify auto-rebuilding, modify background operation rates
Import and clear foreign disk configs = PERC using ctrl R, OpenManage Server Admin
First digit of PE 2900 LCD message code = E = Error
Virtual media support = remotely boot managed systems from virtual media, install apps from vm, update drivers from vm, install os from vm
Running 32 bit diag be helpful = computer can’t access hard drive
OMSA PERC battery learning cycle delayed = NOT 72 hours
Check firmware compatible with drivers in use = OMSA
Test can be run from 32 bit = MpMemory
PE 2900 LCD Messages = written to SEL, listed during POST, displayed with color coded background
Displays on LCD if multiple errors = NOT all messages in sequence; only the most recent message
DRAC supports use of virtual media
Test run from 32 bit = MpMemory
Hot-plug drive replace = automatically rebuild
Modify auto rebuild rate = OMSA
BMC’s available = NOT host in-band, LAN in-band, LAN out-of-band
Management station perform when using virtual media = provides physical media
Run 32 bit = f10
Watch diagnostics run = NOT test selected tab
OMSA = solution for PE systems that provides consolidated and consistent way to monitor, config, update, manage servers
Clear NVRAM = power off server and change NVRAM jumper










Baseboard Management Controller = BMC = proactively forecasting the possible failure of hardware
-          Failovers: monitored and managed by PSU controller and detect a failure and utilize backup.  Controller will perform load balancing to reduce the load on any single PSU which extends mean-time-to-failure (MTTF)
-          Fans are controlled by BIOS and hot swappable
-          Memory redundancy:
o   Spare bank
o   Mirroring
o   RAID
Types: Tower, Rack, SC, Blade
-          Tower = 6800 + 2900
-          Rack = 1-2U in size.  1U = 1.75 inches
-          SC = Cheaper, 2 CPU’s max, 1 PSU
-          BLADE = “server on a motherboard”; large server farm
PE 2950 = Model 2, Gen 9, Rack optimized (5 for rack, 0 for tower), server (0 for server, 5 for blade)
Racks and rails work together in server environment = Rack systems ensure proper closure of servers, rail systems provide easy access
PERC = Poweredge Expandable RAID Controllers; Dell proprietary RAID controller; E = EXPANDABLE and not Edge
Components:
-          Side-plane connector = connecting SAS controller to board
-          DRAC-5 = Dell Remote Access Card 5 = remote manage; dedicated Ethernet port
-          PSPB/PDB = Power Supply Paralleling Board or Distribution Board
PCI
-          PCI = 133mbs
-          PCIX = 1gbs; extended, parallel based
-          PCIE = +2gbs; express, serial based
-          Hot Plug PCI: not supported for Dell RAID and SCSI controllers
o   Off - off
o   Green – On
o   Green blinking fast – slot being identified by app, program, or driver
o   Amber blinking slow – card is faulty or improperly installed
o   Amber blink twice, pause, then repeat – hot plugged expansion card is slower than other cards on same bus
CPU’s
-          AMD Opt 8200, 2200
-          Intel Xeon 7100,5300,5100,5000,3000,Pentium d915, Celeron d336
Power
-          LED:
o   Red or amber = failure
o   Green = ok
-          PSPB:
o   Distributes load across multiple PSUs
o   Larger systems with n+1
-          PDB:
o   Hot plug logic; power distribution
o   Smaller systems with 1+1
o   No load balancing
o   Provides redundancy and hot swapping
BIOS
-          BIOS Sequence:
o   Power supply board turns on and initializes; chipset receives the signal from power supply board; BIOS POSTs; BIOS looks for Video and runs it; memory count up; system inventory; summary screen displayed; search for boot drive; start the process of booting OS
-          Factory default:
o   Alt + f = factory default for entire BIOS
o   Alt + d = single fields in BIOS
o   SCSI enabled will be default
Drives that come with 9th gen servers = SAS and SATA
Networking
NIC Teaming = create a VLAN, load balancing, failover
-          Fault tolerance = Smart Load Balancing (SLB); Adaptive Fault Tolerance (AFT)
o   If one fails, the other will be used
-          Load Balancing = SLB; Adaptive Load Balancing (ALB)
o   Share large data loads preventing one from being overwhelmed
-          Generic Trunking = FEC and GEC/802.3ad; FEC and GEC/802.3ad
o   Link aggregation.  Multiple cables/ports in parallel to increase link speed beyond the limits of any single cable/port
-          Teamed using Adapter Config Utilities
o   Broadcom = BASP; Intel = PROSet
o   Broadcom utility is preferred whenever possible
TOE
-          Removes processor bottlenecks; reduce excessive traffic across internal memory; traffic on internal PCI; Key required
-          Does not support iSCSI.
-          NIC is online before POST.  Must install the TOE key before AC power is applied
-          Layer 4 ethernet
-          BACS2 = Broadcom Advanced Control Suite v2
o   Basic diagnostics on Broadcom
o   Visibility in network stats
o   Teaming wizard
o   Netstat –nt to check for offloaded connections
Management
In-band = agents going through the OS
Out-of-band = through the DRAC and independent of the OS
-          Check for line voltage, verify BIOS, view logs, power on/off, force boot from floppy
-          Once DRAC is plugged in, direct interface with BMC is disabled and can’t use IMPI to talk to BMC

To talk to BMC, use OMSA or RAC. 
DRAC 5 is hardware and software that talks to BMC and takes over once installed on x9xx servers
-          Additional security, ipmi/bmc config capabilities, enable.disable access points and features, SM-CLP (new CLI for RAC), RAC users are same domain as BMC users, Virtual Media is USB  not IDE, hardware chipset and faster processor
-          RACADM = CLI for DRAC 5
o   Both hex and decimal numeric values, displays numeric values as decimal, IPMI config groups
-          DRAC 5 GUI
o   Consistency with RACADM and manageability features; target based rather than functional based navigation; consistency with OMSA gui; enhance server sensor display; ssh, serial, telnet;
-          DRAC 5 Configuration
o   Web based interface; RACADM CLI “cfgLanNetworking”; BIOS BMC Binary (BBB) (Ctrl E setup)
o   Network settings configured by web; RACADM CLI; BIOS BMC Binary (BBB)
-          Virtual Media = USB, floppy, CD, DVD
-          Can’t configure a console redirection session on the local system
System Event Logs (SEL)
-          Ways to view logs:
o   Baseboard Management Controller (BMC)
§  AKA Remote Access Config Utility
§  Ctrl E during POST to view logs
o   Dell System E-Support Tool (DSET)
§  Does not come standard
§  Extracts all event logs for offline viewing (1MB)
o   Dell OpenManage Server Administrator
§  Nice pretty GUI that you can drill down and do lots of things

-          RAC = Remote Access Control
-          DRAC 5 = Dell Remote Access Control
-          SEL = System Event Logs
OpenManage
-          Deployment tools = DSA (Dell Server Assist), DTK (Deployment Tool Kit)
-          Monitoring Tools = OMSA (Open manage server admin), ITA (IT Assitant), RAC, BMC (Baseboard Management Controller Management Utility)
o   OMSA, RAC, and BMC = management solution that provides a consolidated way to monitor, configure, update and manage servers
o   OMSA = does not support SC servers!
-          Maintenance Tools = SUU (Server Update Utility), PED (PowerEdge Diagnostics)
o   SUU = update BIOS, RAC, RAID firmware
-          IPMI = “discover” capabilities of manageable devices
-          DRAC has virtual floppy, CD support and physical drive or image support
-          Remote Management Hardware = DRAC; works out of band, no OS interaction, can work when system is powered down
Storage
SATA
-          Point to point, no master/slave
SCSI
-          Timing errors at higher bus speeds; EMI (Electro Magnetic Interference); Serial bytes converted to parallal data bits, parallel move down bus system, re-serialized at receiving end
SAS
-          Uses proven SCSI functionality
-          SCSI command delivered via a serial topology; 16,387 SAS devices in SAS domain; enhanced SATA while adding support for a second drive port; point to point, switched architecture
-          Point to point, full duplex, dual port, hot plug
-          PHY
o   Like a telephone conversation, source and destination PHY; OPEN -> OPEN_ACCEPT… CLOSE
o   Two narrow links can be combined to become a wide link where each PHY has a unique identifier but share a common SAS address
-          Expanders = port multiplier; similar to an Ethernet switch in that it’s not an end point
-          Connection rate = +3gps; rate matching if connection rate is slower than physical link rate
-          Protocols= SSP (Serial SCSI Protocol) supports SCSI disk, tape, etc, STP (Serial ATA Tunneling Protocol)  supports SATA drives, SMP (Serial Management Protocol) supports SAS expanders
-          SAS domain = SAS devices + 1 or more expander
-          SAS controller online = goes out through each of its phys, Registers every device it comes across, Notes the device WWN, maintains the list of physical disks by WWN
-          If RAID supported, examine RAID info and build map of virtual disks to physical disks
-          Backplanes, slots, enclosures obtained by discovered SEPS
-          Basic SAS controller = SAS 5i = daughter card, I denotes internal cables only, ctrl C BIOS setup
-          Added RAID hardware = PERC5i = daughter card, ctrl R BIOS setup
PERC 5 = PowerEdge Expandable RAID Controller = DDF is stored twice at the end of each physical disk
-          Uses 512mb on each disk for DDF
-          Config data cached during normal operation and NOT on the controller.  Removal of member disks = virtual disk deleted
-          Provides logic that interacts with CPU and memory  or CPU and storage devices to read/write
RAID
-          Stripe order info stored on PERC and each disk, adapters know where disks are
-          Move a disk or replace the PERC = mismatch
-          RAID types = 0, 1, 5, 10, 50
PERC = PowerEdge Expandable RAID Controller
-          PERC 5/i  5 = generation, I = integrated vs controller card
-          Hot spare =  RAID configured with drive already in place; drive roaming = identify drives that have been moved and re-associates the drives SCSI ID with the new slot
-           






BIOS does NOT control initial part of boot process
BIOS checks and configures memory in post process
AC Adapter = power cord + brick
Symptoms of no post = no OS messages, no response from keyboard, no startup sounds, locks up at Dell splash screen
Successful post = keyboard status LED’s flash, OS messages
AC adapter LED changes from solid green to blinking = board
NVRAM = ESCD
HD’s that are replacement will contain diagnostic partition = FALSE
BIOS copied from ROM to RAM during boot = SHADOW MEMORY
POST related fault = Check state of power LED, check diagnostic LEDs, Check AC adapter LED, Refer to online doc
Power up but no video on LCD = check num lock, connect external display, wait for BIST to load
Ink spots on LCD is not covered by support
Wireless unable to connect = NOT confirm card is on, confirm enabled in BIOS, run PSA
LCD distorted = Dell diagnostics and OBD, Update driver




BIOS = Basic Input/Output System
Chassis:  Latitude D, E, Precision, Vostro
Portability, Design, Materials, Tech, Access to hardware
FRU = Field Replaceable Units
-          System board, Video, Audio, NIC, touchpad, LCD + internal memory
CRU = Customer Replaceable Units
-          Keyboard, HD, memory modules, mini-OC cards, Bluetooth cards, modem daughter card, coin-cell battery, main battery, modular drives, external dries, AC Power
Components:
-          Front View
o   Ambient light sensor, keyboard LEDs, Status LEDS, internal microphone, touchpad
-          Bottom View
o   HD, Memory, Battery, Dock connector
Can be removed:
-          AC Power, battery, coin cell battery, memory, keyboard, Bluetooth daughter, expansion card, HD, Modular bays
Keyboard Bexel:
-          Diagnostic lights
-          “lock lights”
Chassis:  XT,XT2
Tablet, integrated pen support, multiple gesture touch screen, digital ink, handwriting recognition
Screen swivels 360
Size/weight, dual mode (pen and touch), structural integrity, usability, performance
On the LCD:
-          Power, Diagnostic LED, Battery LED, Status indicators
-          Wireless switch = FN F2
CRU
-          AC Power, Battery, Bluetooth, pen, express cards, wireless antenna
FRU
-          Ambient light sensor, audio card, bio reader, LCD, processor, board, touch pad, video

BIOS
SSU = System Setup Utility – F2 OR F12 -> system setup
                Detected, enabled/disabled, settings for: power, processor performance, video, etc
Stored in PROM on CMOS chip.  PROM BIOS
Code that allows a computer to boot
BIOS Security Policies
-          BIOS Password
BIOS Level Security
-          Passwords set by user: primary, admin, hard drive
-          Primary = prevents booting any media
-          Admin = boot the OS but prevents BIOS changes
-          HD = HD specific password that will prompt on any machine

POST process:
Power button -> signal through board to processor -> cpu signals soft switched power supply to power up system -> power supply sends current out
Initialize core chipsets, checks and configs memory, enables L1 L2 cache and check cpu, copy into memory

Latitude LED error codes for no post
Flash-off-off = no sodimms present (memory)
Flash-on-on = cpu error
Flash-on-flash = LCD
Off-flash-off = memory compatibility error
On-flash-on = memory detected but has errors
Off-flash-flash = modem
Flash-flash-flash = board
Flash-flash-off = option rom
Off-on-off = HD/storage



Tuesday, August 23, 2011

Smartphone data use comparrison

A couple of months ago I was given an iphone 3 to use since my existing phone was dieing, I was a month or so away from end of contract, and it was cheaper to go onto my g/friends AT&T plan as opposed to staying solo on Verizon.  The price was right.  The phone was free, no contract, and even with the data plan I was paying less because it was a group plan.

This past week we started looking at usage of the phones on her plan in the hopes of finding a way to streamline the bill a bit.  My data package is 2gb for $25 because the 200mb for $15 didn't make sense.  Well I'm hear to tell you that the 200mb plan is looking better for me now that I have a couple of months under my belt but I'm also going to compare my usage with a friend who has an HTC Inspire (freekin' huge), his wife who has an iphone 4, and my girlfriend who has an iphone 4.  I must admit that the graphs showing usage on the AT&T site are pretty and so that is what I will be using as a reference.

First off let's look at my iphone 3 usage:

I came on board at the end of the billing cycle in May which is why there was so little use.  I have wi-fi at home, work, and when i'm at her place.  This is my first smartphone but I have had a phone in the past with some form of internet access on it.

Now let's look at her iphone4 usage:


She has wi-fi access at her place, mine, and her parents.  She does not have wi-fi access at work.  She is also grandfathered in with the unlimited data plan so there's no threat of an overage (yet) in the event that she decides to watch one too many youtube videos on her phone.  She is a long time smartphone user.

Now let's look at my friends HTC Inspire usage:


He too has wi-fi at home and does not have it at work.  He has the 2gb data plan.  The June spike is attributed to traveling out of town and being bored in a hotel.  This is his first smartphone though he has had a phone in the past that had internet access on it.

Finally let's look at his wife's iphone 4 usage:
She too has wi-fi access at home and elsewhere.  Her data plan is 200mb.  The June spike is attributed to user error (forgot to join network while at someones house).  This is her first smartphone and I'm unsure if she's had internet access on her previous phones.

I'm aware that 3 of 4 phones listed are iphones.  An argument that was brought up is that the droid user does not have wi-fi at work which explains the heavier usage.  This is thrown out by one of the iphone 4 users having no wi-fi at work AND an unlimited data plan.

What I see in this data is more how 4 people use their phones instead of what types of phones they are.  I have heard arguments that droid phones use more data which I refuse to believe.  The OS has no affect on data consumption.  It's the applications (dare i say 'apps' for fear of Apple coming after me for using their word?) that are on the phone that initiate the data connection.  To assume otherwise is uninformed about the underlying technology and thus wrong.

I see a husband and wife with smartphones and it can be assumed that they are together more often than not outside of work.  This would imply that they have access to the same wi-fi spots.  If this is correct then one could infer that the usage is a behavioral issue and not a result of the handset.  Feeding into my behavioral theory is that the user who has no wi-fi at work and has an unlimited data plan is actually in the < 200mb range consistently.

All of this came up with my trying to decide what to do about my data usage plan.  I'm currently at 2gb for $25 because i wanted to not feel restrained by my data package.  Because I believe consumption is behavioral, I'm no longer worried about dropping my plan down next month to the lower allotment of 200mb for $15. 

It is my advice to others jumping on the bandwagon to start high and then turn it down after you see some trending.  Some people are heavier users out of habit.  Some are lighter users out of habit.  I apparently am a lighter user and I'm OK with that.

Tuesday, July 19, 2011

FBI Raids Hunting Down Anonymous

Courtesy of CBSNEWS.com

This is of course on the heels of Anonymous threatening to release Sun and News Of The World Emails today after defacing The Sun earlier today...

Can't help but wonder why the FBI is launching these raids.  Why the attention?

Clearly these "hackers" are a threat to national security and will bring down our freedoms and encourage rampant homosexuality and promiscuity and any other nonsense that is being spewed out by hate mongers on both sides.

The fact is yes they've been attacking very large multinational corporations lately.  The reality is it's only a matter of time before law enforcement comes after you when you've been in the headlines as much as they have been.  The fact is Anonymous is a boogie man for law enforcement to chase down and a great way generate news to draw attention away from other more pressing issues.  There are bigger problems in the world than companies like Sony being 'hacked' but law enforcement is doing what is in their best interest (assuming they want to stay employed much longer).  The global economy is unstable right now, countries in Europe are defaulting on their debts, the USA's credit is tanking, oil prices are constantly on the rise courtesy of OPEC (not directly because of BP, Exxon, or the other oil companies kids!!!), and China's economy is expanding at a rate that is not sustainable long term which can lead to a major crash in time.

Yeah.  Chasing down rogue 'hackers' makes a lot of sense.

A part of me now wants to watch the original Hackers movie and yell "Hack the planet" tonight...  :)