find file data integrity errors,"flow chart" for disk repair

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MilesCFA
Posts: 2
Joined: Sat Nov 01, 2014 4:01 pm

find file data integrity errors,"flow chart" for disk repair

#1 Post by MilesCFA » Sat Nov 01, 2014 5:40 pm

I have a failing HDD and it corrupted Windows Backup/Restore function. I’m currently doing a low level format to try to fix any HDD errors (hopefully, but new drives ordered anyway!) but I could use some help. I copied all my data files to my newer PC and since the failing HDD also had a virus, I ran Avast (DOS mode) on the data which was copied to a newer PC. While Avast didn’t find any destructive viruses, it did find a lot of corrupted data files as well as files that were too large for it to check( forget the phrase it used = ”decompression bomb”?) and I cannot save Avast (DOS) logs on my PC (needs floppy or bootable USB).
ChkDsk failed to find any errors; it was Seagate Tools found intermittent drive issues (1st run failed,2nd run passed, but decided to do low level format in an attempt to fix disk errors).
1) Is there any specific software on UBCD that would be best for checking “file integrity” for every file - to discover the corrupted files Avast found that obviously were affected by the HDD failings? Remember, chkdsk did NOT find problems.
Fwiw: Since I have many older backups, I can likely find good copies of corrupted files… once I find out which files were corrupted by my failing disk.
2) Vista repair (on the installation CD) found no errors but apparently I can run the Vista installation disk from within windows and presumably this could correct my Backup/Restore issue. Can anyone confirm this can fix errors not found using the installation DVD repair (I suspect other Windows errors due to failing HDD?
3) If #2 can’t fix my Windows, can I reinstall Vista on top of itself without damaging existing data or other installed software?
4) Is there any forum here that discusses the best “flow chart” for fixing errors? Or how does this look(?):
4a) backup everything (often and especially before starting a repair attempt).
4b) Check for viruses (1st=ALWAYS have/use anti-virus software. fwiw: I’ve owned PCs since the 1970s and as long as you’re “not stupid”, viruses are not typically a problem, especially when you have active anti-virus software).
4c) Windows Backup/Restore (this is a “must use”).
4d) Windows Repair (from installation disk within Windows).
4e) Windows Repair from Installation DVDs.
4f) Reinstall windows over itself (can anyone confirm that this won’t data existing data or other software).
4?) Check for hardware issues: I’m not sure where this should go in the process because, in “all my years”, “real” hardware issues are rare or they are obvious; failing RAMM and HDDs are the exception, because they start slow and BEFORE they become obvious, you’re looking “in a haystack” (4b-4f+).

Thank you for any advice. And fwiw, low level format will not finish for 3 days so I can’t try fixes until then.

ady
Posts: 832
Joined: Sat May 08, 2010 5:26 am

Re: find file data integrity errors,"flow chart" for disk re

#2 Post by ady » Sun Nov 02, 2014 8:06 pm

1_ A so-called "decompression bomb" in Avast doesn't mean the file is corrupted.

2_ "Low level" format is a procedure that used to be available in computers and HDDs around two decades ago, not in current hardware. I doubt you are referring to such procedure. Expecting whichever procedure you are currently performing (which you called "low level format") to span during 3 days might indicate some kind of hardware problem (for instance, it might simply be a cable loosely connected, or a HDD problem). Alternatively, it might be an inadequate configuration of the program you are using to do whatever you are trying to achieve.

MilesCFA
Posts: 2
Joined: Sat Nov 01, 2014 4:01 pm

Re: find file data integrity errors,"flow chart" for disk re

#3 Post by MilesCFA » Mon Nov 03, 2014 8:57 am

Thx ady. It might not be called a low level format anymore, but that's what it is.... what I'm doing a "secure erase" (DOD specs) which writes to each and every space on the HDD, reads it back, then writes it again. This obviously takes a long time on the huge drives of today (even a dskchk takes a lot of time and it ignores unused areas).

And I am 98% it does not indicate a hardware problem (other than the bad areas I know are present); rather, according to Seagate's website, this general process can often discover bad areas on the drive that other procedures will not (ie, dskchk, which, by the way, apparently marks files "good" when it is run, even if it does not fix or cannot find actual corruption), and then the secure erase "repairs" the area by marking it bad and replacing it with "extra" areas on the drive that are there solely as replacements to bad areas.

As for Avast, I also understand "decompression bomb" doesn't mean the file is corrupted, only that Avast can't or won't take the time to decompress to examine the file, it's just I didn't remember if that was "the exact" phrase Avast used. Interestingly, and it was a surprise to me, since Avast has to read/open files to look for viruses, an "undocumented feature" is that it does find corrupted files when it tries to look for viruses. And again, Avast found these issues when dskchk did not.

It's been 20 yrs since I was actually employed as a programmer so please excuse if my "lingo" is out of date, but what I am doing is a valid effort. My HDDs are old and are likely to be close to failing (note, only 1 of the 2 RAID1 drives seems to have problems, and they are intermittent at that), but my primary concern here is to "clean up the bad HDD" so I can restore to it from an old backup before I migrate to new HDDs, all the while keeping the other -RAID- HDD in "reserve"/"preserved" in case my methodology for fixing and migrating my OS/HDD fails.

So my #'d questions remain: in essence, after I restore from an older backup, I still need to check for corrupted files, and I need to fix any Vista software issues, before migrating to new HDDs.

And fwiw, Vista is crap, but I don't want to migrate to 7 because it is essentially obsolete, and 8 is crap... you know MSFT, they cycle "crap", "good", "crap", so I'm waiting for Win10, which they have no choice but to "get correct" (or they will have taken a major step toward obsoleting themselves?), then I'm migrate to completely new HW and SW.

ady
Posts: 832
Joined: Sat May 08, 2010 5:26 am

Re: find file data integrity errors,"flow chart" for disk re

#4 Post by ady » Mon Nov 03, 2014 11:27 am

Well, you are not performing any kind of (low-level) formatting, but wiping. Depending on the tool used, the speed might vary a lot. Depending on the algorithm, the speed might vary a lot.

Some wiping tools might, in some cases, help with "bad sectors". FWIW, the simpler algorithm (one pass, all zero) is enough for personal use.

If you are already planing on using the OS on a new HDD, then there seems to be not much gain by re-installing first on the old HDD just to move the installation to the new HDD.

At any rate, Avast is about malware, chkdsk (and similar tools) is mostly about the filesystem (and in some cases it might help to reduce the chances of using a potentially "bad sector"), and there are other tools for checking the hardware. These are all different things.

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