Defragging

[tysonrss]

Is it even worth it to defrag HDDs now? My last PC, I did a defrag and my boot ini got messed up and the drive itself started making these weird noises. Alas, the HDD gave in.

Because of this experience, I'm hesitant to defrag my drives. Is it useful still or pointless to do?

Quote:As a computer professional of 20 years standing, it is my opinion that defragging is purely an amateurs' time-wasting exercise that "seems" like a good idea. After all, you get to use important-sounding words like "contiguous". Maybe it was a good idea 20 years ago, but now all it does is thrash the HDD. By the way, NTFS was intended to obviate the need for defrag.

[MayImilae]

Well, I don't know how else to put this, so I'll just come out and say it. That guy you quoted is an idiot. Did he ever investigate why defragmenting existed? Why thousands of engineers put it in place in dozens of file systems and operating systems, often enabled by default? I guess they did it because everyone else did it, and because it seemed like a good idea? Oye. I'd hate to see an operating system that was built that way. And no ME jokes please, we all know that was because of a miscalculation of the Ballmer Peak .

Fragmentation is a downside of the hard disk drive technology. It cannot be fixed, only managed. It is a well known problem and engineers have spent years trying to work around it. The only difference between 20 years ago and now is that modern operating systems such as Ext4 and HFS Plus are able to use a variety of tricks to minimize fragmentation, but even they need to be defragmented every once in a while. An antiquated file system like NTFS (19 years old and counting) has little to no protection against fragmentation. Hence every version of windows since Windows XP has had defragmentation of some form enabled by default. Yes, that means that unless you deliberately disabled it, your system has been defragmenting itself already.

So yea, defragmenting is definitely necessary on modern systems. Even Macs. Unless you have an SSD, of course. You do not want to do that.

Quote:As a computer professional of 20 years standing, it is my opinion that defragging is purely an amateurs' time-wasting exercise that "seems" like a good idea. After all, you get to use important-sounding words like "contiguous". Maybe it was a good idea 20 years ago, but now all it does is thrash the HDD. By the way, NTFS was intended to obviate the need for defrag.

How on earth did you even find this guy? It's an anonymous comment on a blog, who's google pagerank is so low this forum post mentioning it ranks higher than it. It's not even an article against defragging, it's a comment on a geek blog about how and why to defragment! Why did you even post it?

[Squall Leonhart]

reducing file acces times (especially for tiny files) is always worth it

[tysonrss]

(07-07-2012, 06:07 PM)MaJoR Wrote: Well, I don't know how else to put this, so I'll just come out and say it. That guy you quoted is an idiot. Did he ever investigate why defragmenting existed? Why thousands of engineers put it in place in dozens of file systems and operating systems, often enabled by default? I guess they did it because everyone else did it, and because it seemed like a good idea? Oye. I'd hate to see an operating system that was built that way. And no ME jokes please, we all know that was because of a miscalculation of the Ballmer Peak .

Fragmentation is a downside of the hard disk drive technology. It cannot be fixed, only managed. It is a well known problem and engineers have spent years trying to work around it. The only difference between 20 years ago and now is that modern operating systems such as Ext4 and HFS Plus are able to use a variety of tricks to minimize fragmentation, but even they need to be defragmented every once in a while. An antiquated file system like NTFS (19 years old and counting) has little to no protection against fragmentation. Hence every version of windows since Windows XP has had defragmentation of some form enabled by default. Yes, that means that unless you deliberately disabled it, your system has been defragmenting itself already.

So yea, defragmenting is definitely necessary on modern systems. Even Macs. Unless you have an SSD, of course. You do not want to do that.

Quote:As a computer professional of 20 years standing, it is my opinion that defragging is purely an amateurs' time-wasting exercise that "seems" like a good idea. After all, you get to use important-sounding words like "contiguous". Maybe it was a good idea 20 years ago, but now all it does is thrash the HDD. By the way, NTFS was intended to obviate the need for defrag.

How on earth did you even find this guy? It's an anonymous comment on a blog, who's google pagerank is so low this forum post mentioning it ranks higher than it. It's not even an article against defragging, it's a comment on a geek blog about how and why to defragment! Why did you even post it?

Because I thought I could relate, after all. After defragging one of my drives, it gave in. Plus the HDD is doing a lot more work when it's defragging.

(07-07-2012, 06:39 PM)Squall Leonhart Wrote: reducing file acces times (especially for tiny files) is always worth it

I suppose so.

[delroth]

(07-07-2012, 06:39 PM)Squall Leonhart Wrote: reducing file acces times (especially for tiny files) is always worth it

Never looked precisely at how NTFS is implemented, how exactly does defragmenting reduce access time for tiny files? If your file fits into one or two 4K blocks it's likely to not be fragmented at all. I think directory indexes are unlikely to be fragmented too if your directory is not very large.

Also, on a SSD defragmenting can help performance by allowing the IO scheduler to merge requests to successive blocks and reduce the number of required interruptions / DMA requests to the disk. It's a very marginal gain though and it makes the disk "die" faster by rewriting a lot of data when it's not really required to have good performance.

[AnyOldName3]

I'd not do it on a cheap SSD, as it's wasting precious limited write cycles, and only expensive ones have the ability to have many rewrites without breaking. However it would also be a bummer to have used up write cycles when they could have been better used in the future when they're expensive on an expensive drive.

[MayImilae]

SSD defragmenting is a BAD idea. The way SSDs work, all sectors are available at all times, instantly, without requiring any seek time. So who cares if a file is scattered all over the NAND chips, if the bits are all in a nice row or scattered all over the place the SSD can still access them all instantly. Defragmenting is a patch to work around a limitation of the HDD technology: the moving read/write head. SSDs don't have them, so it's not needed.

Plus... NAND flash has limited reads and writes, so SSD controllers have tons of technology in place to arrange the files to minimize reads and writes on the individual sectors. You actually want the controlled fragmentation that the SSD controller creates, because otherwise you'll have too many reads and writes on specific sectors and they'll burn out fast. Running a defragmenter will totally screw up all the management work that the SSD controller does.

For some obscenely in-depth reading, check this out. - http://arstechnica.com/information-technology/2012/06/inside-the-ssd-revolution-how-solid-state-disks-really-work/

[AnyOldName3]

That took some reading, but was informative. I'm still not buying an SSD, though, but maybe, in a few years, when I'm rich, will buy a system which caches the HDD to SDRAM on boot. There won't be the fast boot of a SSD, but there'll be much higher speed once it is booted.

[NaturalViolence]

@MaJoR

Read delroths post. Everything he posted is accurate.

[Squall Leonhart]

(07-08-2012, 05:00 AM)delroth Wrote:

(07-07-2012, 06:39 PM)Squall Leonhart Wrote: reducing file acces times (especially for tiny files) is always worth it

Never looked precisely at how NTFS is implemented, how exactly does defragmenting reduce access time for tiny files? If your file fits into one or two 4K blocks it's likely to not be fragmented at all. I think directory indexes are unlikely to be fragmented too if your directory is not very large.

Also, on a SSD defragmenting can help performance by allowing the IO scheduler to merge requests to successive blocks and reduce the number of required interruptions / DMA requests to the disk. It's a very marginal gain though and it makes the disk "die" faster by rewriting a lot of data when it's not really required to have good performance.

its not only fragmentation that affects small file access, but location on the platter. Windows boot logs keep track of what files are accessed in what order and likes to keep these files in order on the disk

Its when you get to poorly made video games that chain content loading from hundreds of package files (the sims does this) that defragging really shows its worth

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the only reason why defragging was suggested initialliy on SSD's was becuase it had the side effect of Trimming the cells