Hard Drive Technologies Lab RAID Redundancy is the

Hard Drive Technologies Lab

RAID �Redundancy is the factor for development of RAID in server environments. �This allows for backup of the data in the storage in the event of failure. [backup and RAID is different] �If one of the drives is failed, it could swapped out for a new drive without disturbing the system performance.

Hardware vs. Software �Hardware RAID �Need intelligent dedicated controller talk RAID �Operating system views it as single volume �Software RAID �Don’t need dedicated controller. �Use ATA controller or SCSI host adapter �Operating system recognizes all individual disks

Personal RAID �ATA RAID controller chips have gone down in price �Some motherboards are now coming with RAID built-in How we can know if your motherboard implement RAID or not? �The Future is RAID �RAID has been around for 20 years but is now less expensive and moving into desktop systems

RAID implementation �There are two common ways of Implementing the RAID. �They are implementing RAID in software and implementing RAID in hardware. Hardware implementation: �The implementing of RAID uses a special controller come with processor to handle the various RAID tasks. The processor is a part of the RAID controller.

RAID Processor

Hardware RAID Implementation IOP �Most common hardware implementation is IOP RAID. ( I/O Processor. ) �The administrator faces the major drawback is cost. Because of the processor and other software’s, IOP RAID is very expensive method. �The separate processor and software give the RAID system greater strength to handle recovery and disk rebuilding. �It is expensive and flexible.

Hardware RAID Implementation IOC �Different approach to implementing hardware RAID is IOC ( I/O Controller ) �Advantage of controller-based RAID is that it is a cheaper form of hardware RAID.

Software RAID �Software RAID can be implemented by operating system. �Driver-based RAID or OS-based RAID �Its cheaper than Hardware RAID. �Software RAID systems are not good performer and are not reliable when compared to hardware RAID. �Software RAID can be useful in small applications where performance is not the matter.

Steps of RAID Every time you try to save file: 1. Data is first sent from server (Computer) to the RAID controller. 2. Then the RAID controller stripes the data. 3. Finally, the striped data is sent to the array.

RAID Levels �RAID ( Redundant Array of Inexpensive Disks). All RAID levels except for RAID level-0 provide some form of data redundancy. �RAID 0 = Striping / no redundancy �Capacity is the combined capacity of all of the member disks �RAID 1 = Mirror, 2 disks, i. e. the second disk is maintained as a duplicate of the first �Capacity is that of 1 of the disks.

RAID Levels �RAID 1+0 = Mirroring with striping, data is striped across half of the disks, and the other disks are maintained as a duplicate of the stripe set �Capacity is half of the combined member disks. �RAID 5 = Striping with parity � 3 or more disks, data is striped across all disks with a parity stripe. Any member disk can fail and the data is re-calculated on the fly using the parity stripe, until you replace the failed disk and the array is rebuilt

RAID Levels Please see RAID EXPLAIND videos: �Part 1: http: //www. youtube. com/watch? v=c. NIf. TV 9 jy 40&feature=ch annel �Part 2: http: //www. youtube. com/watch? v=F_rch. Cjc. Yu 8&feature=Pl ay. List&p=C 38817 BF 7 C 2 FBF 72&playnext_from=PL&playnext= 1&index=1 �Part 3 : http: //www. youtube. com/watch? v=n. CD 52 OJwo. T 4&feature= Play. List&p=C 38817 BF 7 C 2 FBF 72&playnext_from=PL&playnex t=2

Connecting Drives

Connecting your drive �Choosing Your Drive � PATA, SATA or SCSI � Check BIOS and motherboard for support �Jumpers and Cabling on PATA � Master � Slave � Cable Select

Jumpers and Cabling Don’t forget to connect power supply cable

Connecting SCSI Drives �First need compatible controller (Host adapter) � Different types of SCSI [check lecture slide] �Connect data cable � Reversing this cable can damage drive, data or both �Connect power � Pin one goes to pin one �Configure SCSI IDs on drives and controller �Configure Termination if not automated

BIOS Support: Configuring CMOS and Installing Drivers

Configuring CMOS �Enable Controller �Turn on Auto detection �Old HD we need to type CHS. PATA - IDE Channels 1 and 2 SATA - IDE Channels 3 to 6 (note no slaves)

Boot Order �Identifies where computer will try to load an operating system �Always put HD in primary master controller if you have new HD you need to change boot order. why?

Device Drivers �Derives that do not get BIOS via the system BIOS. They required some other source of BIOS. �ATAPI (CD ROM – DVD ROM) Devices need device deriver. �To install these device we need to follow the same step like HD. �Show up in CMOS.

Troubleshooting Three things to get a hard drive installation correctly: 1 - Jumpers 2 -Connectors(data cable, power cable) 3 - and CMOS auto detect.

Troubleshooting �No boot device available �One possibility is that the BIOS settings to enable boottime � autodetection are not correct. � or with its connection to the hard disk controller or motherboard. � If the settings are correctly entered, then there is a problem either with the hard disk

Connectivity

Hard drive error

Hard drive error �This is usually a problem related to the hard disk(s) themselves; this may not mean that the hard disk is bad, but could mean � issue making it impossible to find the hard disk. � incorrect cabling � The controller or interface to the hard disk could also be at fault.

�No fixed disk present �Hard disk drive not connected properly �Jumpers not set properly �CMOS not setup properly �Hardware is bad

HDD controller failure �Incorrect data in CMOS setup (wrong or missing drive geometry, drive not "enabled", etc. ). This can be the result of a failing CMOS battery or accidental user intervention. �Master Boot Record and/or Partition Table for the boot drive is mangled. (we will see it in Next chapter) �Improperly mastered/slaved IDE drives.

HDD controller failure �Incompatible IDE drives (example: many Conner drives will not work when installed Slave and another brand of drive is set as Master). �Active Primary partition is non-bootable (bad boot record, etc. ). (we will see it in Next chapter) �Adapter not firmly seated in slot. �Hard drive cable loose or twisted, or has a broken wire. �Drive or adapter failure. Not frequent, but it does happen

Reference �http: //searchstorage. techtarget. com/tip/How-will-you- implement-RAID �What is RAID http: //www. youtube. com/watch? v=Y 7 v. Z 3 ZWk. NVA Nawal Muhammed 2011