[SOLVED] Partition seems healthy, but can't defrag?

[Will Robinson]

Perhaps someone can help me solve this mystery?

I have a 1tb partition (on a 4tb Seagate drive) which seems completely healthy and works fine, but I recently tried copying large files to the partition and noticed incredibly slow transfer speeds.

My first instinct was that the disk might be failing, but I've checked it with CrystalDisk, HD Tune, GSmartControl and SeaTools and they all say the disk/partition is healthy.

So then I wondered if it was just a case of bad fragmentation, since I use the partition for torrents. My defrag software confirmed that it was heavily fragmented - but when I tried to defrag it just kept going and going - for weeks, seemingly without any progress. I tried using a different defrag program, and that one wasn't able to defrag it either - the defrag just kept hanging and failed.

But other than this, the partition/disk seems to work fine - as does the other partition on the disk.

Any ideas?

 

[Starcruiser]

What are you copying the large file from? If it's a slower medium like a USB then that would be expected.

How full is the partition in question? Are the other partitions exhibiting similar failures to defrag?
An almost full partition will normally have extreme difficulties defragging, if it does it at all, since that requires relocating file fragments on the disk until there's as few fragments as possible. Torrents are absolutely awful for fragmentation, but you can mitigate that by telling the app to pre-allocate the file space before downloading.

Just because tools say the disk is healthy doesn't mean it is. It just means as far as the disk itself can tell it's fine, but mechanical issues aren't normally detected until it's too late.

 

[Will Robinson]

What are you copying the large file from?

Just from another hard drive. Files copy fine between all my other drives, but if I copy any file to this one partition it's incredibly slow.

How full is the partition in question?

Approx 80% full

Are the other partitions exhibiting similar failures to defrag?

No.

Torrents are absolutely awful for fragmentation, but you can mitigate that by telling the app to pre-allocate the file space before downloading.

Thanks, I will do that in future

Just because tools say the disk is healthy doesn't mean it is. It just means as far as the disk itself can tell it's fine, but mechanical issues aren't normally detected until it's too late.

Thanks. Do you happen to know any way of telling if a disk is really healthy?

 

[fzabkar]

You could perform a full surface scan with HDDScan. It will identify any "slow" sectors.

https://hddscan.com/

 

[Will Robinson]

You could perform a full surface scan with HDDScan. It will identify any "slow" sectors.

https://hddscan.com/

Hey, thanks. I've downloaded that program but don't know how to do the full surface scan. When The only options I see are "Verify", "Read", "Butterfly" and "Erase"?

 

[fzabkar]

https://www.ghacks.net/2012/12/27/test-your-hard-drives-thoroughly-with-hddscan/