Chapter 10 Implementing Hard Drives (220-902)

Cluster

A cluster is a bunch of sectors grouped together and referring to them as a single unit. Also called File Allocation units.

Bootable media

Any removable device the has a bootable OS is considered a boot device or boot disc Your system boots off the boot device that, which then loads some kind of OS that enables you to partition, format, and install OS on your new hard drive. Boot devices come from many sources. All Windows OS installation media are boot devices, as are Linux installation media Boot devices may also be a medium that has an image of an installation disc. These images are usually stored as a file with a name that has an extension of ".iso" Image files may be on a traditional boot device, such as disc of flash drive, but they can come from any place, such as on a network drive

Striped volumes

Are RAID 0 volumes. You may take any two allocated spaces on two separate hard drives and stripe them. But again, if one fails hen the whole drive is lost.

Mirrored volumes

Are RAID 1 volumes. You may take two unallocated spaces on two separate hard drives and mirror them. If one of the two mirrored drives fail, the others keep running

FAT 64

Breaks the 4 GB size barrier, supporting files up to 16 EB and a theoretical partition limit of 64 ZB. The FAT 64 file system makes the cluster entries 64 bit instead of 32 bit. FAT 64 still lacks all of NTFS cool features

Disk Initialization

Disk Management enables you to view the drive status of every mass storage device in your system. Foreign drive: you will see this when you move a dynamic disk from one system to another Formatting: When you are formatting a drive Failed: disk is damaged or corrupt; you lost data Online: Good healthy disk Offline: Corrupted or having communication problems

partition boot sector

Each partition has a boot sector

Disk Installation

Every hard drive in a Windows system has special info placed onto the drive through a process called disk installation (Comp TIA refers to this as Initializing a disk) Initialization includes info that defines what it does in the system. If the hard drive is part of a software RAID, for example, its RAID info is stored in the initialization. If it is part of a spanned volume, this is also stored there. All new drives must be initialized before you can use them To initialize a disk, right-click the disk icon and select Initialize. Once initialized, you can see the status of the drive.

Hard drive formatting

Formatting does two things: makes the file system and the root directory in that file system. The root directory provides the foundation upon which the OS builds files and folders.

Formatting

Formatting installs a file system onto the drive that organizes each partition is such a way the the OS can store files and folders on the drive. When you format a disk, all data is completely erased from the hard drive.

GRUB (Grand Unified Bootloader)

Free Linux-based boot manager that is used to control multiboot setups. Basically the boot manager software takes control from the MBR and asks which OS you want to boot

Maintenance

Hard drive maintenance can be broken down into two functions: checking the disk occasionally for failed clusters and keeping data organized on the drive so it can be accessed quickly

basic disk

Hard drives that uses either the MBR partitioning scheme or the GPT partitioning table. Dynamic doesn't do basic disks.

Disk Clean Up

If your hard drive becomes filled with temporary files, use DiskClean up to get rid of them. Windows saves files that you never see by: Files in Recycle Bin, Temporary Internet files, Downloaded program files, and temporary files Mac OS X and Linux do not have disk clean up. Use a 3rd party tool.

Error-checking

Individual clusters sometimes go bad. So it is important that you occasionally check for bad clusters on drives. Tools used to check bad clusters are: Scan Disk and chkdsk. These are command line utilities. Microsoft calls the Error-checking in current versions of Windows Mac OS X uses the Disk Utility Linux offers a command line tool called fsck All of the 3 do the same job: Find bad clusters (Your system won't put data in bad clusters when found). lost chains= clusters that have no file name associated with them. When you use chkdsk you get two options: Automatically fix file system errors and Scan for and attempt recovery of bad sectors. Only use the second option if you actually suspect something because it takes a while. In Mac OS X, when you use disk utility you get two options: Verify Disk or both Verify Disk and Repair Disk. Verify Disk finds errors and Repair disk fixes them. You can verify but not fix errors on Mac OS X. If errors occur on start up disk, reboot and press APPLE KEY - R until recovery partition loads. Linux usually runs fsck by itself so do not worry Run Error-checking about once a week

FAT 32

Individual files can't be over 4 GB Does not work on drives larger than 2 TB Used for flash drives the are between 4GB and 32 GB. Mainly used for flash media and USB. Not partitions.

Simple spaces

Just pooled storage. Has multiple drives or whatever capacity added together to form a single virtual drive. No resiliency = drive fails, data gone. Simple spaces are good for temporary storage, scratch files, etc.

Window's three different partitioning methods

MBR partitioning scheme, Window's proprietary dynamic storage partitioning scheme, and the GUID partition scheme (GPT). GUID = Global Unique Identifier

Mac OS X file systems

Mac OS X uses the Hierarchical File System Plus (HFS+) by default, although you can read and write to several different file systems with the OS. The latest versions can read and write to FAT 32 and FAT 64 but can only read NTFS.

File systems in Linux

Most Linux distributions use a file system called Fourth Extended File System (ext4) by default. Some older distros use one its predecessors, such as ext2 or ext3. Ext4 supports volumes up to 1 EB with file sizes up to 16 TB and is backwardly compatible with ext2 and ext3 Linux file system capabilities exceed past those of Mac OS X, being able to read and write to NTFS, FAT 64, HFS+, and ext2, ext3, and ext4.

NTFS

NTFS is neat because it has a lot of great features. This is the main file system we use. It utilizes an enhanced file allocation table called the Master File Table (MFT). If you want to be nerdy and look at your NTFS version type in cmd: fsutil fsinfo ntfsinfo c: Security: NTFS view individual files and folders as objects and provides security for those objects through a feature called the Access Control List (ACL) Compression: NTFS enables you to compress and individual files and folders to save space on a hard drive. Compression makes access time slower because the OS has to uncompressed files every time you use them, but in a space limited environment compression would be ideal. Windows Explorer/File Explorer displays file names for compressed files in blue. Encryption: a big advantage of NTFS is encryption. Encryption makes your file unreadable to anyone that does not have the right key. You can encrypt a file, folder, or a folder full of files. Microsoft calls the encryption utility in NTFS Encrypting File System (EFS), but remember that it is an aspect of NTFS, not its own file system. Disk quotas: NTFS supports disk quotas, enabling admins to set limits on hard drive space usage for users. To set quotas, you must log on as admin, right click the hard drive name, and select properties. In properties dialog box, select the quota tab and make changes. Disk quotas are used on multi user systems (like workplaces). Cluster sizes: unlike FAT or FAT 32, you can adjust the cluster sizes in NTFS, although you will rarely do so. By default, NTFS supports partitions to 16 TB on a dynamic disk and 2 TB on a basic disk. By tweaking cluster sizes, you can get NTFS to support partitions up to 16 EB.

Mounting Partitions and Folders

Partitions and volumes can be mounted as a folder on another drive, known as a mount point. This enables you to use your existing folders to store more data can fit on a single drive or partition/volume To create a mount point, right-click on an unallocated section of a disk and choose New Simple Volume. In a second screen you can choose a mount point rather than a letter.

Other levels of RAID

RAID 5 needs at least 3 drives. Provides performance and redundancy. Disk management cannot do any nest RAID arrays. So if you want RAID 0+1 or RAID 1+0 (RAID 10), you need to use a 3rd party software (or go with hardware RAID).

Other partition types

Swap partition: is like a page file. When physical RAM runs out information gets put into a swap partition. This is used in Linux and UNIX systems. Hidden partition: a primary partition that is hidden from your OS. Only special BIOS tools can access it. Hidden partitions are used by some PC makers to hide a backup copy of an installed OS. You can use this to install your OS in case trashed.

FAT/FAT16

The basic storage area for a hard drive is a sector; each sector = 512 bytes Floppies used ancient 12 bit FAT New FAT16 supports 2 GB a partition

Master Boot Record (MBR) (1st type of partitioning scheme)

The first sector of an MBR hard drive contains MBR. This helps it boot and it is located in sector 0. MBR supports only primary and extended partitions. A primary partition can boot but an extended partition can't. Partitions inside an extended partition are called "logical drives". Support up to 4 partitions. Supports any partition under 2.2 TB Every partition has the capability to be active but only one can be active at a time.

Partioning

The process of electronically subdividing the physical hard drive into smaller units. A hard drive must have at least one partition, and you can create multiple partitions if you'd like. In Windows, each partition is typically assigned a letter like C: or D:

Creating Partitions and Volumes in Disk Management

To create a new volume, right-click an allocated part of the drive and select New Simple Volume. Specify the volume and click Next. By default, Windows does not allow you to choose between a Primary and Extended partition. The first 3 volumes you create will be primary and every volume afterwards will be a logical drive in an extended partition (for MBR style drives) Partition is 4 GB format as FAT, NTFS, FAT32 Partition is 4 GB < x < 32 GB then format as FAT32 or NTFS Windows requires NTFS on any partition greater than 32 GB quick format does not test the disk clusters as part of the format process, while full format does

Defragmentation

Try to defrag your hard drive monthly for maintenance. Schedule to run at night cause it is boring If you do not defrag your system will be slower. If no error checking you could lose data. NEVER defrag an SSD. Will shorten its lifetime

Spanned volumes

Use unallocated space on multiple drives. Risky cause if one drive fails the entire volume is lost.

Disk Management

Used to manipulate installed disks and to manage newly installed disks. Primary tool for partitioning and formatting drives after installation.

Fragmentation

When parts of a file are scattered across the hard drive. This makes your hard drive run slow. Make sure to Defrag your hard drive monthly to ensure top performance. Defrag is crucial for top performance.

File deletion

When you Delete a file it is not actually deleted. It just goes to the Recycle Bin. To actually Delete a file you need to go to the Recycle Bin and Delete it. Once you Delete a file from the Recycle Bin many people consider it to be gone completely. Well that is false. All deleting a file does is alter the info in the folder. The first letter of your deleted file is changes to the Greek letter sigma. The info is still on the hard drive. It is just moved to a hidden directory that you can access via Recycle Bin. All of the data is still intact , you could use a program to change the sigma back into the original letter to get your file back. You have to make sure to not over write anything after you Delete the file because you can not get it back if it is overwritten. If the file has not been Deleted all the way, so to speak, you access it via Recycle Bin and click Restore. For example: Piriform Recuva is a good piece of software to recover files

Partitioning and Formatting with Installation media

When you install on OS, Windows makes two partitions: a 100 MB System Reserve and the C: partition. If you have gone through the partitioning process and have changed your mind, now wanting to make the hard drive use the full terabyte (instead of 500 GB) you simply click the Extend button and apply the rest of the allocated space to the hard drive

File systems in Windows

Windows uses four files systems: FAT, FAT 32, NTFS, and exFAT (FAT64)

Storage Spaces

With Windows 8 and later versions of the OS, you can group one or more physical drives of any size into a single storage pool. These drives can be internal HDD or SSD or external storage connected via USB. Storage spaces functions like a RAID management tool. To make a storage space: Storage Spaces- create new pool and storage space- select the drives you want in the pool- create pool (Storage spaces will show you the installed and formatted drives and warn you that the drives you select will be erased). Once you have created a pool, you need to select the resiliency mechanism, which essentially means providing one or more layers of redundancy so you can lose a drive or two and not lose any data. Storage Spaces off 3 different types of Storage Spaces: Simple, Mirror, and Parity When a disk fails in a space, Storage Spaces sends a warning through the standard Windows Action Center. Storage Spaces enables you to do one more very cool action: future proof your storage needs. The thin provisioning feature means you can create a space with more capacity than your current physical drives provide. For example, if you have three 3 TB SSDs and a 1 TB HDD, you can assign whatever capacity you want, like 12 TB, because you know your movie collection will grow. When you are about to reach the limit of that capacity, Storage Spaces will tell you and enable you to add more physical capacity. Thin provisioning means that you do not have to redo an array or space when you reach the limits of current hardware. SSDs are great for two way or three way mirror. HDDs are best with parity.

Simple volumes

Work a lot like primary partitions. Example: if you have a hard drive and you want to make half of it E: and the other half F: you create two volumes on a dynamic disk that's it.

Mirror spaces

Work like a RAID 1. The number of drives in the array determines which mirror options you have. Two-way mirror: requires at least two drives Three-war mirror: requires at least five drives

Globally Unique Identifier partition table (GPT)

Works a lot like MBR but a little different. Can have up to 128 partitions Partitions can be larger than 2.2 TB GPT uses LBAs instead of sectors. LBA 0 is where the boot information is and LBA 1 is the GPT header. You can configure the 64 bit version of Windows to boot fro, GPT only if you use a UEFI supported motherboard.

Parity spaces

Works like a RAID 5 or 6. Parity spaces is more efficient than two way mirroring. The downside to Parity spaces is that the performance overhead to manage parity spaces can have a significant impact on overall performance. Microsoft recommends using parity spaces for big files that do not change a lot, like your movie collection. You can lose one drive and recover in a three drive parity space. It takes a seven-drive parity space (at minimum) to enable you to recover from a two-drive loss.

When to partition

You usually partition when you install an OS on a new system and when you add an additional drive to an existing system. On old Windows OS we used FDISK to partition drives. Modern Windows uses Disk Management. Linux use to use FDISK but now it uses 3rd party partitioning tools.

Dynamic disks (2nd type of partitioning scheme)

not limited to only 4 volumes, can make as many as you want A Dynamic disk is still a partition but it can do things a regular partition can't You can implement RAID, span volumes over multiple drives, and extend volumes on one or more drives. introduced in Windows 2000 You can create dynamic disks from basic disks in disk management. Once you convert a drive from basic to dynamic you will no longer be able to use primary and extend Converting a disk from basic to dynamic is easy, just right click the drive icon and select Convert to Dynamic Disk Dynamic to basic is different though. You first have to delete all of the volumes off of the drive. After that you can convert it.