Re: (Re ** 6)[1]: Extending "thin_trim" (about pseudo-raid: Why!)

[Zdenek Kabelac <zdenek.kabelac@gmail.com>]

Dne 20. 11. 24 v 2:28 "Thomas Brücker" napsal(a):
> Dear Mr. Kabelac,
>
> * I have had two (real!) cases which three mechanical harddisks, that have
> had defective sectors (within warranty time!), not just announced as
> defective, but really unreadable.
>
> 1st case: Two ecolocical, energy saving samsung disks, that have both got
> unreadable sectors, happyly mutually not on the same location, connected
> as raid1: All data could be read and saved.
>
> 2nd case: An usb-disk that had got unreadable sectors with a 'pseudo-raid'
> on it: All data could be read and saved.


Hi


Any device that is showing  'error' sectors (aka  smartctl shows badblocks, 
uncorrectable errors)   should be ASAP 'recovered/copied' to another new disk 
- and such faulty disk should no longer be used for anything you care about!

If you think  the disk is still 'good enough' to not be thrown to 
trash/recycle bin -  you could probably do a surface analysis - and i.e. 
allocate partitions on a drive in such a way that HUGE portion of drive before 
and after the error  is left  as not being used/allocated   (works for HDD -   
for SSD/NVMe this obviously makes no sense) -  so then HDD reading heads are 
not damaging those errori places any more - and then you can try to use it to 
store something unimportant - i.e.  3rd. backup of something....

Using faulty drive as 'daily work  disk'  with the idea you've 'saved' 
something  makes no sense - you are just preparing yourself big troubles....


> * Experimental case: Test of 'pseudo-raid' on a dvd, the dvd was scratched
> and could partially not be read: The pseudo raid could be read without any
> problem (


Just backup all your DVDs on TiB drives  while they are still readable....


>
> * I have had at least two (real) cases of harddisks with each having a
> unreadable first sector (== the partition table): The laptops could
> neither

Such drives are simply an electronic waste for recycling...


> * So, for me, it is a good idea, to protect myself from defective sectors.
>
> * 'Normal' raid(1):
>    * notebooks with two harddisks in it ...?
>    * travelling with a laptop and two usb-harddisks ...?


Seriously you should really use real  raid1 instead of these rather highly 
'questionable' data protection ideas...  (if you care about your data)

And yes - all notebooks I know  have at least  2 slots for drives - one is 
typically equipped when being sold - other one is usually empty - one just has 
to dismount laptop cover and add the drive to unused slot...


Regards

Zdenek