[opensuse] [OT] is there a virtual machine that uses harddisk as harddisk image
Hello. I am just thinking, from the experience that Microsoft SQL can make use of a harddisk instead of database file as storage of database and improve performance, could virtual machine software make use of a separate harddisk instead of a disk image to improve its performance? I could equip it with SCSI harddisk or SSD harddisk to further improve performance. If it is possible, which virtual machine emulator could do that? (vmware?) This is different from the other frequently discussed topic on the Internet: "could I use the same harddisk partition that I use to dual-boot to run as virtual machine harddisk image?" This topic should have been discussed before but it is difficult to google. What keyword can I use to google? "use harddisk as harddisk image" gives 100 pages of unrelated topic. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Saturday May 30 2009, Zhang Weiwu wrote:
Hello. I am just thinking, from the experience that Microsoft SQL can make use of a harddisk instead of database file as storage of database and improve performance, could virtual machine software make use of a separate harddisk instead of a disk image to improve its performance? I could equip it with SCSI harddisk or SSD harddisk to further improve performance.
If it is possible, which virtual machine emulator could do that? (vmware?)
VMware supports it. I use it for my Windows XP. In fact, Windows XP sees a whole drive in what is actually a single partition of one of my physical drives. It's bit odd, but it works fine. To wit: # file -s /dev/sda2 /dev/sda2: x86 boot sector, Microsoft Windows XP MBR, Serial 0x44c644c5; partition 1: ID=0x7, active, starthead 1, startsector 63, 41929587 sectors # fdisk /dev/sda2 Command (m for help): p Disk /dev/sda2: 21.4 GB, 21476206080 bytes 255 heads, 63 sectors/track, 2611 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x44c644c5 Device Boot Start End Blocks Id System /dev/sda2p1 * 1 2610 20964793+ 7 HPFS/NTFS
...
Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Hello. I am just thinking, from the experience that Microsoft SQL can make use of a harddisk instead of database file as storage of database and improve performance, could virtual machine software make use of a separate harddisk instead of a disk image to improve its performance? I could equip it with SCSI harddisk or SSD harddisk to further improve performance.
If it is possible, which virtual machine emulator could do that? (vmware?)
VMware supports it. I use it for my Windows XP. In fact, Windows XP sees a whole drive in what is actually a single partition of one of my physical drives. It's bit odd, but it works fine.
It's also possible in Virtual Box, although not as cleanly as in VMWare. There has been loads of discussion about how to do this over in the Ubuntu side of the world.... and what's done there is basically equal to what you would need to do in openSUSE to achieve the same. See: http://blarts.wordpress.com/2007/12/06/how-to-run-virtualbox-using-a-physica... http://forums.virtualbox.org/viewtopic.php?t=1565&highlight=raw+disk+access http://forums.virtualbox.org/viewtopic.php?t=333&highlight=createrawvmdk http://ubuntuforums.org/showthread.php?t=769883 for a few examples C. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On 2009-05-31 10:56:42 +0800 Randall R Schulz
On Saturday May 30 2009, Zhang Weiwu wrote:
could virtual machine software make use of a separate harddisk instead of a disk image to improve its performance?
VMware supports it. I use it for my Windows XP. In fact, Windows XP sees a whole drive in what is actually a single partition of one of my physical drives. It's bit odd, but it works fine.
What is the name / terminology used for this? If you give me the right keyword I should be able to google out everything. By the way do you know if I can convert an existing hard-disk image file to a real arddisk? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Monday June 1 2009, Zhang Weiwu wrote:
On 2009-05-31 10:56:42 +0800 Randall R Schulz
wrote:
On Saturday May 30 2009, Zhang Weiwu wrote:
could virtual machine software make use of a separate harddisk instead of a disk image to improve its performance?
VMware supports it. I use it for my Windows XP. In fact, Windows XP sees a whole drive in what is actually a single partition of one of my physical drives. It's bit odd, but it works fine.
What is the name / terminology used for this? If you give me the right keyword I should be able to google out everything.
As far as I know, there's not special name for it, nor is there anything you're likely to find on Web. When you define a virtual machine you have the option of having the virtualized disks be backed by files (considered the default) or by actual disks or disk partitions.
By the way do you know if I can convert an existing hard-disk image file to a real harddisk?
Offhand, I don't, but there's probably a tool for doing it. And you can always do it from "inside" the virtualized environment, where the OS sees that storage as a real, physical disk. If it's the boot drive, imaging it wouldn't be advisable, but if the drive can be unmounted, then simply copying it at the physical level would suffice. I should point that this capability exists in VMware Workstation. I don't know if it's in the free Server product (it lacks many of the features of Workstation), so you should check that, too. VMware Workstation isn't exactly inexpensive. Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
In <200906010717.06296.rschulz@sonic.net>, Randall R Schulz wrote:
On Monday June 1 2009, Zhang Weiwu wrote:
On 2009-05-31 10:56:42 +0800 Randall R Schulz
wrote:
On Saturday May 30 2009, Zhang Weiwu wrote:
could virtual machine software make use of a separate harddisk? VMware supports it.
QEmu/KVM does too. I'm pretty sure you can convince Xen to use a file or any block device as well. However, this may or may not actually increase your performance, depending on the virtualization software. If they use the same techniques as the kernel uses for swap files, the performance increase is tremendously minimal.
What is the name / terminology used for this? If you give me the right keyword I should be able to google out everything.
As far as I know, there's not special name for it, nor is there anything you're likely to find on Web. When you define a virtual machine you have the option of having the virtualized disks be backed by files (considered the default) or by actual disks or disk partitions.
any "block device" -- these are devices that support read, write, and seek operations like "normal" files. -- Boyd Stephen Smith Jr. ,= ,-_-. =. bss@iguanasuicide.net ((_/)o o(\_)) ICQ: 514984 YM/AIM: DaTwinkDaddy `-'(. .)`-' http://iguanasuicide.net/ \_/
On Monday June 1 2009, Boyd Stephen Smith Jr. wrote:
... If they use the same techniques as the kernel uses for swap files, the performance increase is tremendously minimal.
And, in the limit, extremely zero.
What is the name / terminology used for this? If you give me the right keyword I should be able to google out everything.
... When you define a virtual machine you have the option of having the virtualized disks be backed by files (considered the default) or by actual disks or disk partitions.
any "block device" -- these are devices that support read, write, and seek operations like "normal" files.
Do you know any block devices these days that aren't disks or flash drives? I'm pretty sure DECtape is officially obsolete. While magtape had block interfaces (at least in the old Bell Labs Unix), they were not truly (or even virtually, like DECtape) random-access. (I did once try mkfs-ing and mounting a magtape. It was interesting to watch...) So it's a distinction without a difference. Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Monday 01 June 2009 17:23:42 Randall R Schulz wrote:
Do you know any block devices these days that aren't disks or flash drives?
Optical devices (CD, DVD, BluRay), iSCSI, FCoE, ATAoE, nbd, loopback devices, ram disks
I'm pretty sure DECtape is officially obsolete.
I have seen people export tape devices as nfs shares. Not sure what brand it was, but it seemed to work (but slooooow of course :) Anders -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Monday June 1 2009, Anders Johansson wrote:
On Monday 01 June 2009 17:23:42 Randall R Schulz wrote:
Do you know any block devices these days that aren't disks or flash drives?
Optical devices (CD, DVD, BluRay), iSCSI, FCoE, ATAoE, nbd, loopback devices, ram disks
And how many of them (that are not in fact disks or intermediaries to disks) are suitable for acting as the physical storage for a VMware virtual disk? Certainly not any of the optical types. The rest are interconnects or mediators to some physical storage. If that storage isn't random access (disk), then it's not suitable as the physical representation of a virtual machine's virtual disk.
I'm pretty sure DECtape is officially obsolete.
I have seen people export tape devices as nfs shares. Not sure what brand it was, but it seemed to work (but slooooow of course :)
Magnetic tape (of the standard 9-track variety, at least) is not rewritable because the drive does not ensure that a new record precisely aligns with the one being overwritten.
Anders
Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Monday 01 June 2009 18:03:38 Randall R Schulz wrote:
On Monday June 1 2009, Anders Johansson wrote:
On Monday 01 June 2009 17:23:42 Randall R Schulz wrote:
Do you know any block devices these days that aren't disks or flash drives?
Optical devices (CD, DVD, BluRay), iSCSI, FCoE, ATAoE, nbd, loopback devices, ram disks
And how many of them (that are not in fact disks or intermediaries to disks) are suitable for acting as the physical storage for a VMware virtual disk? Certainly not any of the optical types.
Aside from performance, why not? Most of the time a disk doesn't even have to be writable. It is perfectly possible to have almost all your file system running on a DVD (for example), though from a performance perspective perhaps not desirable
The rest are interconnects or mediators to some physical storage. If that storage isn't random access (disk), then it's not suitable as the physical representation of a virtual machine's virtual disk.
The way you write "random access (disk)" makes me think you somehow equate the two, and obviously if you say "anything that is usable as a root device is by definition a disk" then it is obviously a disk. But I don't accept that equality. The point was that any block device can be used, simply because they behave in a sufficiently equivalent way. None of the ones I listed are disks, but they share behaviour with disks, not because they are disks in any way, but because they speak the same communication protocols as disks of various types. What is at the other end of that protocol is supposed to be a black box, as long as it fulfills the semantics of the protocol.
I'm pretty sure DECtape is officially obsolete.
I have seen people export tape devices as nfs shares. Not sure what brand it was, but it seemed to work (but slooooow of course :)
Magnetic tape (of the standard 9-track variety, at least) is not rewritable because the drive does not ensure that a new record precisely aligns with the one being overwritten.
As I said, I don't know what they were using exactly, but it was definitely a tape drive of some kind. Not to be recommended, of course Anders -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Anders Johansson wrote:
On Monday 01 June 2009 18:03:38 Randall R Schulz wrote:
On Monday June 1 2009, Anders Johansson wrote:
On Monday 01 June 2009 17:23:42 Randall R Schulz wrote:
Do you know any block devices these days that aren't disks or flash drives? Optical devices (CD, DVD, BluRay), iSCSI, FCoE, ATAoE, nbd, loopback devices, ram disks And how many of them (that are not in fact disks or intermediaries to disks) are suitable for acting as the physical storage for a VMware virtual disk? Certainly not any of the optical types.
Aside from performance, why not? Most of the time a disk doesn't even have to be writable. It is perfectly possible to have almost all your file system running on a DVD (for example), though from a performance perspective perhaps not desirable
Consumer grade optical media degrades too fast to be really useful for anything that requires regular RW access, and unfortunately any requirement for a any part of a FS to be writeable may require optical media writes to be made whether or not a change is made to the user data on the media. I refer you to... http://fy.chalmers.se/~appro/linux/DVD+RW/ For a starting point for a more detailed technical overview... - -- ============================================================================== I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone. Bjarne Stroustrup ============================================================================== -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkok5WkACgkQasN0sSnLmgLxBgCg5Y9saitg6BSHlpIZ9IgyOKB2 IBEAnA2gHJt7YtXQyegs/nlKy2giveIw =2pUw -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
In <200906010823.43037.rschulz@sonic.net>, Randall R Schulz wrote:
On Monday June 1 2009, Boyd Stephen Smith Jr. wrote:
What is the name / terminology used for this? If you give me the right keyword I should be able to google out everything.
... When you define a virtual machine you have the option of having the virtualized disks be backed by files (considered the default) or by actual disks or disk partitions.
any "block device" -- these are devices that support read, write, and seek operations like "normal" files.
Do you know any block devices these days that aren't disks or flash drives?
The ones that come to mind for me are dm-devices, md-devices, luks devices, and the special case dm-devices, LVM logical volumes and EVMS "logical volumes" (I don't remember the correct EVMS terminology). At the end of the day, block writes are usually destine for spinning platters, flash chips, or RAM chips; that's true. However, there may be a number of useful layers between the media and virtual machine software and the VM doesn't care as long as it exposes a block device interface. -- Boyd Stephen Smith Jr. ,= ,-_-. =. bss@iguanasuicide.net ((_/)o o(\_)) ICQ: 514984 YM/AIM: DaTwinkDaddy `-'(. .)`-' http://iguanasuicide.net/ \_/
On Mon, Jun 1, 2009 at 10:17 AM, Randall R Schulz
On Monday June 1 2009, Zhang Weiwu wrote:
On 2009-05-31 10:56:42 +0800 Randall R Schulz
wrote:
On Saturday May 30 2009, Zhang Weiwu wrote:
could virtual machine software make use of a separate harddisk instead of a disk image to improve its performance?
<snip>
By the way do you know if I can convert an existing hard-disk image file to a real harddisk?
Offhand, I don't, but there's probably a tool for doing it.
Never tried, but I'd be very surprised if a simple dd did not do the trick. dd if=<virtual-drive-file> of=/dev/sdx Then fix the vm config to use that drive / partition. fyi: I have more confidence you can work with partitions than with full drives. In that case, dd if=<virtual-drive-file> of=/dev/sdxn where x is the drive identifier and n is the partition identifier Greg -- Greg Freemyer Head of EDD Tape Extraction and Processing team Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Monday June 1 2009, Greg Freemyer wrote:
On Mon, Jun 1, 2009 at 10:17 AM, Randall R Schulz wrote:
...
By the way do you know if I can convert an existing hard-disk image file to a real harddisk?
Offhand, I don't, but there's probably a tool for doing it.
Never tried, but I'd be very surprised if a simple dd did not do the trick.
dd if=<virtual-drive-file> of=/dev/sdx
That certainly won't work. VMware virtual disk files are not simple byte-for-byte images of the virtual disk's contents.
...
Greg
Randall Schulz -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Mon, 1 Jun 2009, Randall R Schulz wrote:-
On Monday June 1 2009, Greg Freemyer wrote:
Never tried, but I'd be very surprised if a simple dd did not do the trick.
dd if=<virtual-drive-file> of=/dev/sdx
That certainly won't work. VMware virtual disk files are not simple byte-for-byte images of the virtual disk's contents.
That's true for an expanding disc image but, looking at a hex dump of the first 512 bytes of a pre-allocated disc image, it looks like it would for the pre-allocated images. It would also appear to work for pre-allocated Virtualbox disc images as well, however you'd need to skip the first 33280 bytes. To do this, you'd need to set a block size of 512 and use "skip=65" to skip over the extra data. As for writing the expandable disc images to a physical device, you'll probably need to create a pre-allocated disc image to match the size of the expandable disc image and then use dd to copy the discs inside the virtual machine, before being able to copy as you would with a pre-allocated disc image. There may be a tool available that can convert from an expandable to a pre-allocated disc image, either for VMware or Virtualbox, but I don't know of one. Having used Parallels in the past, I know it has such a tool for working with its own disc images. I have a vague recollection that it may be able to handle VMware disc images, but can't be certain about that. Regards, David Bolt -- Team Acorn: http://www.distributed.net/ OGR-NG @ ~100Mnodes RC5-72 @ ~1Mkeys/s openSUSE 10.3 32b | openSUSE 11.0 32b | | openSUSE 10.3 64b | openSUSE 11.0 64b | openSUSE 11.1 64b | RISC OS 3.6 | RISC OS 3.11 | openSUSE 11.1 PPC | TOS 4.02 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Tue, 2 Jun 2009, David Bolt wrote:-
It would also appear to work for pre-allocated Virtualbox disc images as well, however you'd need to skip the first 33280 bytes. To do this, you'd need to set a block size of 512 and use "skip=65" to skip over the extra data.
Okay, that won't work for all drive sizes. The offset depends on the
size of the disc image, and 65 would only work for an 8GiB image. The
exact offset can be calculated by reading the 32bit (64bit?) value at
offset 0x158. The following simple program should suffice:
===== START =====
#include
On Monday 01 June 2009 17:17:19 Greg Freemyer wrote:
Never tried, but I'd be very surprised if a simple dd did not do the trick.
dd if=<virtual-drive-file> of=/dev/sdx
That's unlikely to work, but in qemu there is a tool called qemu-img, which can be used to convert between various formats. I haven't actually tested this, but something like qemu-img convert -O raw <input file> /dev/sdx should work Anders -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
In <200906011800.56336.ajohansson@suse.de>, Anders Johansson wrote:
On Monday 01 June 2009 17:17:19 Greg Freemyer wrote:
Never tried, but I'd be very surprised if a simple dd did not do the trick.
dd if=<virtual-drive-file> of=/dev/sdx
That's unlikely to work,
At least not with VMWare or VirtualBox. However, QEmu and KVM both support a disk image type of "raw" which is really just plain old disk image as created by dd or other "stupid" tools. I'm pretty sure Xen doesn't do any adorning of the images by default, either. -- Boyd Stephen Smith Jr. ,= ,-_-. =. bss@iguanasuicide.net ((_/)o o(\_)) ICQ: 514984 YM/AIM: DaTwinkDaddy `-'(. .)`-' http://iguanasuicide.net/ \_/
participants (8)
-
Anders Johansson -
Boyd Stephen Smith Jr. -
Clayton -
David Bolt -
G T Smith -
Greg Freemyer -
Randall R Schulz -
Zhang Weiwu