partitioning interview questions
Top partitioning frequently asked interview questions
Can anyone recommend a cheap/free utility that can do this without very much effort?
My preference is that it would be really easy.
- Boot into Windows
- Pick drive to move
- Pick target drive
- It copies everything over, and reboots to the correct partition.
Recently I purchased an ADATA C802 8GB flash drive. Since the drive was new I decided to run some of the HD Tune Pro (v4.50) performance tests on it, mostly just for the heck of it.
To avoid accidentally destroying data HD Tune refuses to write to a drive unless there are no partitions on the drive. If you do attempt to write to a drive with partitions, it posts the message "Writing is disabled. To enable writing please remove all partitions."
As you would expect, the ADATA came formatted with a single primary FAT32 partition in the Master Boot Record. But a number of unexpected things happened when I attempted to delete that partition.
The first thing I tried was to use the Windows 7 (64-bit) Disk Management tool (
diskmgmt.msc) to delete the partition. It would not let me. The context menu choice to delete that volume was not available.
Next I opened up a command prompt window with Admin authority and ran
diskpart. Diskpart deleted the volume for me. However, when I attempted to run an HD Tune write test on the drive I still got the "Writing is disabled" message. Huh???
So I fired up a utility I happen to own which allows viewing drives at the sector level and verified that the partition table in the Master Boot Record was empty. No partitions. Yet HD Tune still thought there were partitions on the drive?
So why was I still getting the "Writing is disabled" message from HD Tune Pro?
And why wouldn't the Windows 7 Disk Management tool let me change the partitions on this drive.
After doing the above, I plugged the ADATA into my MacBook. I was then able to format it as either a GPT or MBR partitioned drive with no problems. I am not looking for suggestions on how to format this drive. I can do that.
What I do not understand and was hoping I might get insight into is why this drive behaves so strangely under Windows 7? And BTW, what's up with HD Tune Pro?
BTW, if I plug the drive I formatted on my MacBook back into my Windows 7 64-bit system I still run into road blocks with the Disk Management tool. For example, I cannot delete all the GPT partitions on the ADATA so I can convert it into an MBR drive. I followed Microsoft's instructions, the instructions just do not work with this ADATA flash drive.
Anyone know what's up with this? It makes no sense to me. Has something changed in Windows 7 (Vista)??
I've taken the plunge and bought an SSD and want to move my existing Windows installation over. The current hard disk is 500Gb, but I've trimmed the contents down to about ~40Gb. I'm transferring it across to a 100Gb SSD and looking for the easiest way just to copy everything across and set the SSD up as a boot device.
I've looked at a few tools like Macrium Reflect, but they don't seem able to restore to a smaller drive. Do I need to go for something like PING to do this? I'm trying to avoid scary Linux-based boot utilities if possible, does anyone know of an easier way?
I can't find a way to move the partition /dev/sdb2 to the end, where 12GB are free.
I can resize (expand) the partition, but not create (insert) any free space in front of it.
How to do the trick?
(There are 2 small black arrows on the top of the popup window in the screenshot at the side of the blue box that represents the 400 GB sdb2 - I can only move the right arrow to the right, which extends the size, but I cannot move the left arrow. When I enter something in the free space preceding box it is always reset to zero by the programm immediateley)
I hope I explained this well enough, please feel free to ask for details.
This is serious for me as I am expanding a live image.
Maybe there is another solution with linux commandline tools ?
Background: I am using VirtualBox installed on Windows 7. From within VirtualBox I am using Xubuntu as a virtual OS. The reason I chose this approach is so that I don't have to keep turning off Windows and rebooting from Xubuntu every time I needed to switch OSes. And VirtualBox's seamless mode is pretty amazing to allow me see Xubuntu and Windows 7 all in one screen.
Issue: Now I am thinking of a way to have Xubuntu more integrated into my system. By this I mean I want to have a physical partition for Xubuntu. But I want to still have the feeling of the seamless mode.
Question: So finally, my question is: is it possible to load a partition in VirtualBox as a virtual OS?
Case examples: Ideal scenario would be: I physically boot up and login to Windows 7. Now I want to access Xubuntu, so I load VirtualBox and access my Xubuntu partition without rebooting. And the other way around too, i.e. I boot up the system, login to Xubuntu, and can access the actual Windows 7 partition through VirtualBox.
Other info: Please note that I am not talking about getting access to files, as I have a completely separate partition for my files, and am very familiar with VirtualBox's Shared Folders option.
What is the maximum number of partitions we can make on hard disk in Windows?
If it is limited to some particular number, why can we assign all the letters C through Z to drives? If it is a special case, what's that?
I'm reinstalling Windows 7 64 bit, and I encountered an issue I've never seen before. I have a legit copy of Win 64 Professional, and I've installed it probably a half dozen times on this machine in the past without a problem.
Googling the error only brings me to issues with people who are upgrading to win7.
The drive itself seems to not have a problem. I can mount it on other systems and I can create an NTFS partition on it on other machines. I can install Ubuntu on it without any issues. Additionally, if I try using my alternate backup hard drive, the installer gives the same error.
I have run
diskpart from the setup page and
clean seems to report that all is well. However, I cannot get past the screen below, which says
Setup was unable to create a new system partition or locate an existing system partition. This happens regardless of whether or not the disk space is already allocated.
What is causing this? How do I solve or get past this?
Edit: One Week Later
I am at my wits end with this... I have tried installing windows on four different hard drives, using two completely different motherboards, I even borrowed a copy of Windows 7 Ultimate as well as my legit Win7Pro disk. I have tried with no existing partitions, and with existing (and fully functional) NTFS partitions. I've tried installing off of USB and DVD. Every time I get to the screen shown above I get the same result.
One of the reasons that some folk partition hard drives is that certain parts of the hard drive are supposed to be faster than others. Considering that HDDs are a serial access medium, partitioning, in addition to creating logical partitions, also map to a particular physical set of clusters/blocks on the hard drives
Now, with SSDs, its a whole different ballgame - wear leveling would rely on data being writable anywhere on disk, and with serial access, fragmentation has less of an effect
So.. do partitions on SSDs correlate to physical sectors on a disk like HDDs, or is it abstracted away at a higher level?
As we know, in Windows the partition location is prefixed with
[a-z]:. What happens if there are more than 26 partitions?
How do I repartition an SDHC card (4 GB or more)? Do I need third-part tools or Linux (a live CD solution would be OK)?
In Windows' Disk Management the option Delete Partition is dimmed out:
I can reformat the card as FAT32, copy files to and from the card and even change the file system to NTFS using the command line command CONVERT, but not repartition it.
The article How to Partition an SD Card in Windows XP talks about using "a Windows enabler program" which sound rather dubious to me.
I have tried to change from “Optimize for quick removal” to “Optimize for performance”. The option to format as NTFS appeared, but the Delete Partition option is still dimmed out.
I have also tried on different versions of Windows and with different cards with the same result:
- Kingston 4 GB SDHC card, speed class 4 (the one shown in the screenshot)
- Transcend 2 GB (not marked as SDHC, but SD)
- Windows 7 32-bit (albeit with a somewhat an older card reader) and Windows XP 32-bit on an EliteBook 8730w
I have just sat down to install debian 7, which contains something called 'EFI' which is entirely new to me.
I went through the install as I usually do;
- 256MB /boot partition, bootable, unencrypted
- Remaining disk size as / partition, encrypted
The installer warned me about 'no EFI partition found' but I ignored it, because I like to live dangerously.
But that installation isn't bootable, grub complains about 'ELF magic' and drops me into rescue mode.
So I'm now running through the installation again, and have found the option for creating an EFI partition. My questions are as follows;
- What is it?
- Why do I seem to require one now?
- Do I still need a separate /boot partition?
- I have windows 7 installed on the same disk, which always worked fine with grub2 from the mbr, is it possible to rescue that installation as well?
With FAT16 the maximum partition size is 2GB when your maximum cluster size is 32K.
This is calculated by multiplying the number of addressable units by the cluster size.
(216 Allocation units) * (215 bytes/cluster) = 2 GiB
However with FAT32, when I do the same calculation I get a much larger number than the 8 TiB maximum when using 232 clusters.
(232 Allocation units) * (cluster size)
If I use a cluster size of 512 bytes, I've already arrived at 2 TiB.
In an XP TechNet article, Microsoft says
The maximum possible number of clusters on a FAT32 volume is 268,435,445, and there is a maximum of 32 KB per cluster, along with the space required for the file allocation table (FAT).
This puts the maximum cluster size at 228 - 11.
Why is the maximum number of clusters in FAT32 228-11 and not 232, given that it was 216 in FAT16?
GPT (GUID Partition Table) partitioning has some benefits over MBR (Master Boot Record), including Support for:
- More partitions (128)
- Drives larger than 2 TB
But are there any other benefits like less likelihood of corruption? (The two HD failures I've had were corrupt MBRs). Or are you just playing wack-a-mole where the GPT then gets corrupt in the same way?
I have noticed that when installing Ubuntu some people create multiple partitions for directories. Like one for root, one for home, one for boot. What is the advantage to doing this over installing them all on one partition, assuming there is only one hard drive?
Why is it that I see an
A: drive and a
C: drive but not a
Is there a reason why the disk partitions start at C? And is it possible to change that letter designation?