1 Topic by helterskelter

  • helterskelter
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Topic: Slow disk access and missing files after shrink and move

Hello all.

This is the first time I write in the forum. I've searched for similar questions but couldn't find a related post.

I was about to make a fresh install of my Ubuntu OS, but first, I wanted to gain some free space for my home partition as I had like 60 GB of free space from usr and root partitions. I used GParted from the Ubuntu 16.04 live (GParted 0.25.0). My hdd (500 GB) partitions was as follows:

Dell Backup (107 MB FAT) | Recovery (21 GB NTFS) | windows 7 (107 GB NTFS) | swap (2.1 GB) | root (30 GB ex4) | usr (90 GB ex4) | home (224 GB ex4)

So there were 3 operations that I wanted to perform: first to shrink and move partitions root and usr and then resize the home partition.

After 6 hours aprox, the work was done. Unfortunately, I realize that many files from my home partition were lost and the disk access now it's extremely slow. Slow as my laptop won't boot, and it takes about 10 minutes to start a live version of Ubuntu.

I've used gparted many times in the past, and never had an issue like this before. Here are the results of the process:
https://pastebin.com/UFY1S2D3

I have some questions regarding these problems:

1) First of all, do you have any clue of what would be the reasons of the extremely slow disk access after performing these operations?
2) The several errors shown in the results file could be related to physical problems with the disk? The disk didn't exhibit any symptom of problems in the past.
3) and finally, do you think is there anything I can do to restore the data?

Any help would be very much appreciated.

Regards.

2 Reply by gedakc

  • gedakc
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Re: Slow disk access and missing files after shrink and move

helterskelter wrote:

1) First of all, do you have any clue of what would be the reasons of the extremely slow disk access after performing these operations?

Based on the gparted_details.htm log file (thank you for providing this) it appears that many file system corruption errors were discovered, and also there are several "short reads" reported which tend to indicate that the disk drive is failing.  With a failing disk drive, the OS will try a number of repeated reads before giving up and moving on to attempt to read the next block.  This can take a long time and would explain why the disk access is slow.

You can check if the hard drive is failing with a tools such as gsmartcontrol, which is included with the GParted Live image.

helterskelter wrote:

2) The several errors shown in the results file could be related to physical problems with the disk? The disk didn't exhibit any symptom of problems in the past.

If the disk performance was fast before, then it is likely that the data that was being accessed was not on the failing portions of the disk surface.  Slow disk access occurs when trying to access portions of the disk surface that are failing.  After moving partitions it is now likely that some data now resides on the failing section of the drive.

helterskelter wrote:

3) and finally, do you think is there anything I can do to restore the data?

Your best bet is restore data from backup.  If you do not have any backup then you might try a file level recovery tool such as photorec which will scan the disk surface looking for files it recognizes.  Note that this is a very time intensive process that does not recover the file names, and because partition moves were performed the likelihood of good results is low.