Partitions

Some understanding of partitioning and file systems is necessary if Linux is to be added to a computer. This understanding is likely to be in the experimenters who are attracted to rather than repelled from doing more with a PC than having just Microsoft Windows. Experimenting is necessary if one wants to have an IT career. One can learn about partitions on Wikipedia. I am noting some things here, also.

Each partition on a hard drive acts as if it is it's own hard drive, so a 200GB drive can be redone to be like four 50GB drives. You can format a data partition without affecting the other partitions on the hard drive.

Even with ordinary Windows, multiple partitions are sometimes on the drive. There may be a backup partition that can be used to restore Windows in case of a crash. This backup partition is often D:. The swap file (for Windows or Linux) is sort of a partition. But it is normal for a computer sold with Windows to have one hard drive and one partition, C:. This is a significant limitation and is a lack of flexibility for a user who might wish to have a data partition, a backup partition, or alternate operating systems.

If you install Linux onto a hard drive, as opposed to doing Linux from a "live CD" or live USB memory, Linux needs at least one partition plus a swap partition. (Linux, as opposed to Microsoft Windows, can be installed into any partition, even on a logical drive.) Early in a Linux installation, a screen appears asking if you want to install to hard drive or run Linux as a trial without changing the Windows partition. The choice for installing to HDD is followed by a repartitioning process whereby the Linux installer does something like defragmenting, opening up the requested gigabytes for new partition(s). I have always had success with this, but some people have had Windows disabled and have lost the data and programs on the Windows side. This is such a threat that the average parent needs to think hard before letting a son or daughter install Linux. Lingering users of Windows XP should know that retailers do not have XP for sale anymore; some computer shops can reinstall XP for a fee but lost data may stay lost. XP users should also know that their older computer probably does not have the memory to support Windows 7 or 8, so if XP is important on the older computer, you are quite boxed in about recovering from a repartitioning failure. Backing up your data and photos onto CD, USB memory, or an on-line service continues to be a fundamental need for all computer users.

On the other hand, almost any old PC, even with 300MB of memory, can make a fine Linux box. This is a way to put an old PC to good use. A great learning setup is to put two old PCs, loaded with Linux, onto a $20 networking switch and use them to do some networking.

The basic Linux partition requirement is a swap partition and an ext2, ext3, or ext4 partition for Linux. Many books advocate having an added, two-gigabyte partition for /boot and maybe for some of the other Linux directories. It is a good idea to leave free or unallocated maybe 20% of the hard drive. Some towers have a place to put a second hard drive, for the experimenter with some cash. But be careful to buy the proper type, IDE (PATA) or SATA.

On GRID computer booted in Linux, the A drive is above and the B drive is below. These are viewed with Ubuntu disk utility, which is under Administration. The 41GB NTFS is for Windows. There seems to be only one primary partition, as the extended partition is the only other partition on SDA. The Linux swap partition is shown in green. The 37GB ext4 partition is for Linux, where /, /home, /boot, /var, etc. are if I didn't set them up within SDB.

The B drive is below. In green is an NTFS partition, followed by a FAT partition. I use these to pass data between Windows and Ubuntu. It looks like SDB has two primary partitions and an extended partition, plus 37GB of free space that could be a third primary.

The screen below is the view of sda & sdb from Windows XP, Disk Management. All drives have the familiar letter designations. Linux ext3 and ext4 partitions are shown as Unknown. Microsoft programmers have full knowledge of Unix/Linux functioning but are prevented by Microsoft, we can guess, from revealing information about competing operating systems. Note that, as always, Windows must be in the first partition of the first drive.

A property of a partition is that it has one file system. For a Windows partition, it is likely to be NTFS. For Linux, it is likely to be ext4. The one OS has a limited or nonexistent ability to see into the file system of another OS. A good common denominator is a partition that is fat16 or fat32 or vfat, so an added fat32 partition is a way to pass files between OSs. On the Linux side, you have to mount such an added partition. A USB drive is often a fat file system, by the way. (FAT is File Allocation Table.) Windows 8 servers will have ReFS, and this new file system may show up on Windows 8 clients as Windows 8 marketing progresses.

Anyone doing repartitioning needs to know about the limit of four primary partitions per drive, or three if you want an extended partition with many logical drives. Windows must be allowed to have the first primary partition on SDA.

Programs such as Internet browsers and "office" software are compiled for one operating system. You can buy Microsoft Word for Windows, Mac, or Linux, but each program is only usable for the OS that it was compiled for. The great thing about Linux is that hundreds of Linux programs can be downloaded for free. Why Linux programmers put so much work into programs for which there is no way to make money is a puzzle. Maybe having your name in a Linux program improves your chances of being hired for paid programming.

April 6 2013--While investigating new, custom ANODE computer, "GPT" partitioning for USB drive (live boot) for Linux shows up. Wondering--what partitioning does Win8 use? Can Win8 and newer Ubuntu see each others' partitions? I think Win8 only uses GPT. Whether Win8 and Ubuntu can see each other's partitions may depend simply on whether they can see each other's file systems, like NTFS for Win and ext4 for Linux.

Software RAID Mirroring in Windows 8.1 is so Easy

Nov 12 2017 The ANODE computer currently has three HDD, Seagates, 500GB. The first one is for the OS. The other two have been Storage Spaces as encrypted BitLocker, which was the experiment in 2013. But I lost track of the long passwords when we moved from Augusta GA to Austin in 2016, and the BitLocker files weren't important anyway. I figured I would repartition the second and third drives and use them for backing up files. Using Windows Disk Management, it was easy to delete the old partitions and set up new partitions. As I was right-clicking new partitions, I saw a feature of Storage Spaces I had not noticed before, "Add mirror," "Extend Volume," "Shrink Volume." This appears to be

That looked fine, and I clicked Yes. I at once saw that Disk Management had grabbed its own selection of mirror, from the unallocated room on Disk5, which was OK with me. See the red partitions below. Disk Management proceeded to do a synchronize operation on H: (both of them) and that took hours.

Then I looked at Internet to see what I could pick up about all this. https://www.howtogeek.com/109380/how-to-use-windows-8s-storage-spaces-to-mirror-combine-drives/

has a lot of information. It led me to the Start screen in Win8, and I typed in Storage Spaces. The screen below was available.

What is interesting is that I had not created a storage pool. It must come about automatically from the operations above.

But there is something strange about the screen above. StorSpacExperNov20 and StorSpacTryFor2nd is from the first time I did Storage Spaces, in 2013. The one is mirror and the other is parity. In this screen, it declares them to still be in existence but not formatted. That doesn't sound right at all!

As for the physical drives, there are the three Seagates. The pool capacities seem reasonable. It is odd that the % used is about the same in all three.