HDD question

[The Natural Philosopher]

It seems that windows is actually *less* picky than Linux then

[Johnny B Good]

A straight sector by sector copy (dd or dd_rescue running under a 'Live CD' booted OS) will guarantee a bootable clone where the disk is cloned to an equal or larger capacity disk (you can always extend or add partition space to a new larger disk after the cloning operation if the left over space is significant).

The only concern I have when cloning a HDD to a SSD is the question of where the partitions start from in relation to the SSD's Erase Block (EB) size which, afaicr, doubled up from 16KB to somewhere around the 128 to

256KB mark. Unless you're cloning a really old, pre-AF (4096 byte sectors) HDD, alignment to the 4096 byte sectors used by all SSDs should be guaranteed (important to writing performance and the issue of write amplification with SSDs - less so with regard to read performance).

However, misalignment to the EB might be a significant factor in an SSD's write/erase performance but I really don't know just how significant this is in practice. What I do recall is that Microsoft claimed that their later disk partitioning utilities supplied with win7 were SSD aware and would automatically align partitions to a 2MB boundary to cater for all foreseeable EB sizes likely to be used by later generation SSDs.

# Personally, I think FDISK/PARTDISK simply used 2MB boundaries regardless of disk type since you'd have to go back to the days when

700quid was a bargain price for a 1GB full height 'Monster Drive' before wasting 2MB on a 200MB HDD could by the slightest stretch of the imagination be considered, at a mere 1%, any loss at all.

IOW, it looks like Microsoft not only considered the AF issue but also the EB issue when they updated FDISK/PARTDISK for win7. The question that remains is "Does partitioning to an SSD's EB boundary size actually matter? If starting from scratch, losing a mere 2MB of disk space on even a tiny 16GB SSD is neither here nor there so you may as well assume a 2MB starting point is "A Good Idea" even if it only seems like it might eliminate a write/erase performance penalty that may or may not exist in reality.

However, when it comes to cloning a correctly formatted AF HDD does it matter that the partitions may not necessarily be aligned to the SSD's EB size? I'm only raising the question here since I don't know whether it's not been mentioned simply due to oversight or due to the fact that Microsoft's apparent concern with aligning partitions to a 2MB boundary has no real basis in fact.

[pamela]

I was thinking that if a single partition (not the whole volume) is cloned then perhaps the MBT on the target volume does not get updated or is updated but the entry is not in the same position as before (which perhaps Windows expects).

Also, Windows unofficially uses a couple of bytes deeper in the MBR to allocate drive letters which I imagine does not get copied and I wondered if booting the new system partition with additional volumes might fail if these were not lettered in a particular way.

Just guessing. :) I use a partition manager which avoid such possiblities so I don't know if they occur in other situations.

[PeterC]

Macrium uses the Volume Shadow Copy service to clone the OS partition.

[John Rumm]

Most of the windows tools like Acronis are not brute force sector by sector copiers - they usually do a certain amount of reconstruction on the fly and "smart" copying so as to not copy what it expects to be unused sectors, and to dynamically resize on the fly.

Yup partitions built by Vista are later are usually OK. Alignment on ones created under XP can have problems though.

Shades of 640K should be enough for anyone ;-)

On my first HDD that would have been 5% of its capacity!

The smallest SSDs I buy these days are 240GB, so I can live with it.

I have not seen it mentioned as being an issue in the same way that AF misalignment is. It may be a reflection of the way that NTFS does not reuse freed space until forced to - so it can probably trim large blocks of pages together anyway.

[Fredxx]

I'm with TNP here. I cloned a laptop conventional hard disk onto an SSD using clonezilla and the result was that Windows required re-licensing.

I'm genuinely surprised you think differently. If only because Windows keeps a log of hardware, and where there's a material hardware change, say a motherboard or disk, it will ask for the licence number.

[The Natural Philosopher]

The smarter the disk gets the less it matters. As I have pointed out, possibly elsewhere, there is no 1:1 mapping of what sector you specify, to what physical sector is used on an SSD. There is a map connecting te two and a small operating system running iniside the disk to handle write requests by parcelling them out to whatever physical sector hasn't been written to as much, yet.

It's called 'wear levelling'.

Whether or not sector alignment matters is rather down to what particular algorithm is in play. And how big the 'raw sectors' or blocks are, on that partiucular SSD.

And this hoary old chestnut is out there on the internet with loads of false information, even from people who should know better.

My advice is ignore the issue. Its a bit like the really old days when we used to wroite 'C' with an underlying resp[ect for te archiercture we are on and the comp-ilers we were using.

Today, the compilers are so good,and understand the architecture they are to run on so well, that one doesnt have to bother, and, furthermore, the CPUS themselves are optimsied to run the C code.

SSDs will buffer write requests until they have a nice large chunk of data, and then try and do it all at once to a fresh less used sector.

Which may or may not respect virtual sector boundaries.

[The Natural Philosopher]

^^^^^^^^^^^^^^^^^^^^^^^^^^^ Nver underestimate the power of well crafted bullshit.

[Brian Gaff]

That depends on what you mean by clone of course. Brian

[Brian Gaff]

Yes as long as the cloning does not take place while windows is actually running and the booting info is copied and there are no jumpers to worry about it does work. The issue with some of the cloning software that stays inside windows is that windows locks some files when its running and they cannot be copied. Brian

[Andy Burns]

VSS allows the cloning app to take a 'crash consistent' point in time snapshot of the drive, even when windows is running,

[dennis]

I frequently clone the running windows system partition. Windows has code in it specifically to allow it to do so. It has had it in for years.

Software like arcronis, uses it as well as the disk imaging software built into windows.

[dennis]

No it won't. One change like a HDD will not require relicensing. Changing to a new MB and a new HDD might. The effects are cumulative over some time period.

I have yet to need to get a license when cloning a windows disk to put back into the same machine. Even if you do it still boots and runs unlike what TNP says and you can relicense by clicking the activate button.

[dennis]

More bullshit from TNP.

[Andrew]

What do people use to expand/contract partitions these days ?.

Partition magic was brilliant but only worked up to XP. I cannot install in Win7 Pro (But I haven't tried the XP emulator).

[T i m]

Especially if as you say it isn't a fresh installation.

Again, with a lower chance over time.

The more time goes by the less likely it would require re-authentication.

I think I might have had to in a tiny number (of very many) instances of complete system drive cloning.

Of all things I wouldn't take any notice of any Linux Fanboys is advise about Windows. They are by definition against it no matter what (in spite of being forced to rely on it for some 'Windows only' solution in many cases).

But the point that in most cases you can boot Windows into a Safe Mode

*GUI* and easily run diagnostic stuff is for those of us who aren't CLI jockeys is a real boon (but would often prompt a fresh install of Linux for many).

Cheers, T i m

[T i m]

I use Gparted (from a Linux LiveDVD / USB).

I also used PM to good effect but Gparted has replaced that pretty well 100% now (unless I'm using something like Acronis and do it there at the same time as cloning).

Cheers, T i m

[T i m]

All the PC's and laptops here are backed up daily (if they are on) to my WHS and that provides a 'bare iron' network recovery via a generic boot CD.

I've used it a few times now when HDD's have failed catastrophically and it works really well.

It does slow this old XP machine quite a bit while it does the backup but it's pretty slow in the first place (it's a very mature and well abused XP running on a Mac Mini).

Cheers, T i m

[Andy Burns]

GParted live USB

Though I begin to worry that Win10 is "mucking" with NTFS to add weird and wonderful features, with no alteration of the NTFS version visible to 3rd party programs, so they may have a less than full understanding of the data they're messing with ... of course you'd only resize a partition you had backed-up, right?

[Huge]

Better yet, don't use Windows.