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Questions tagged [zero-fill]

9 questions
54
votes
9 answers

How to zero fill a virtual disk's free space on windows for better compression?

How to zero fill a virtual disk's free space on windows for better compression? I would like a simple open source tool (or at least free) for that. It should probably write an as big as possible file full of 0and erase it afterwards. Only one pass…
mit
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6 answers

/dev/zero equivalent in windows?

I am trying to use the windows version of dd to copy a RHEL iso to a USB stick. However, I wanted to zero out the drive first to ensure there is no filesystem on it before writing it out. Is there an equivalent of /dev/zero in windows that I can use…
Matthew
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11
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6 answers

How can I compact the VHD file with Ubuntu?

I use windows server 2008r2 with role Hyper-V. The guest system is Ubuntu 12.04 LTC. It is situated on the dynamic virtual hard disk. I want to compact this VHD (The real size is 50 GB, 360 GB on the disk). But I can not do this, because the Ubuntu…
AmShegar
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6
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2 answers

Automatically delete files by writing zeros on Linux

We run thin-provisioned Ubuntu VMs which do a lot of file writes and deletes. Whilst the disk use on the guests increases slowly (net writes - deletes) the size of the virtual disk on the hosts grows much more quickly because the hosts have no way…
David Semeria
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5
votes
5 answers

WipeDrive Utility?

What is the best and fastest wipe drive (zero fill) utility that can be burned to a CD?
Kredns
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2
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2 answers

zeroing a disk with dd vs Disk Utility

I'm attempting to zero a disk on my Mac OS X machine. I'm going for complete zeros and unformatted, so I think of dd. Unfortunately the maximum throughput I've managed to get out of dd is 7MB/s. Just for grins I tried disk utility and it has a…
jdizzle
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1
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3 answers

Truncate empy space from a raw dd image

I have a raw disk image I took using dd of a Ubuntu instance. The total disk size is 300 GB, but only 5.5 GB used. Is there a way to resize the raw dd image down to 20 GB, keeping all of the 5.5 GB of data, and just truncating empty blocks?
Justin
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0
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1 answer

dd or cat - overload when read /dev/zero

I need reclamation thin disk, so Im trying fill zero on vhdd. But when I run it, so server is overload with 20k IOPS and full satured SAN network. Can you help me how I can slow b/w for this? E.g 10MB/s Tried this: ionice -c 3 dd if=/dev/zero…
Pavel
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0
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1 answer

What could cause files to end up zeroed out?

A client sent us an external hard drive where at least half the files are corrupt. They are broad mix of filetypes (images, documents, etc) and there is no discernible pattern into which are corrupt. They appear as their original size, however, when…
user354104
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