<html><head></head><body style="zoom: 0%;"><div dir="auto">Zdenek is right </div> <div dir="auto">But if in this exact moment one or more drive do have not only bad sectors "reallocated" but also "pending" ones </div> <div dir="auto">the best choice is to preserve them shutting them off and allowing a PRO cloning process with machines like PC-3000 </div> <div dir="auto">But first at a PRO lab, they will open the drive in clean room for the sake of check and verify WHY SMART are so bad for such amount of sectors </div> <div dir="auto">If recovering the data is a must, failing the preservation of the bad SMART drives , will result in loosing them and together the data too. </div> <div dir="auto">Read on the data recovery guide published on the website of the told company </div> <div dir="auto">R. </div> <div dir="auto"> </div> <div class="gmail_quote" >Il giorno 12 apr 2023, alle ore 12:20, Zdenek Kabelac <<a href="mailto:zdenek.kabelac@gmail.com" target="_blank">zdenek.kabelac@gmail.com</a>> ha scritto:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> <pre class="blue">Dne 09. 04. 23 v 20:21 Roland napsal(a): <blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #ad7fa8; padding-left: 1ex;"> Well, if the LV is being used for anything real, then I don't know of anything where you could remove a block in the middle and still have a working fs. You can only reduce fs'es (the ones that you can reduce) </blockquote> my plan is to scan a disk for usable sectors and map the logical volume around the broken sectors. whenever more sectors get broken, i'd like to remove the broken ones to have a usable lv without broken sectors.</blockquote> Reall silly plan - been there years back in time when drives were FAR more expensive with the price per GiB. Todays - just throw bad drive to recycle bin - it's not worth to do this silliness. HDD bad sectors are spreading - and slowly the surface gets destroyed.... So if you make large 'head-room' around bad disk areas - if they are concentrated on some disk area - and you know topology of you disk drive like i.e. 1% free disk space before and after bad area - you could possibly use disk for a little while more - but only to store invaluable data.... <blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> since you need to rebuild your data anyway for that disk, you can also recreate the whole logical volume. my question and my project is a little bit academic. i'd simply want to try out how much use you can have from some dead disks which are trash otherwise... </blockquote> You could always take 'vgcfgbackup' of lvm2 metadata and make some crazy transition of if with even AWK/python/perl - but we really tend to support just some useful features - as there is already 'too much' and users are getting often lost. One very simply & naive implementation could be going alonge this path - whenever you want to create new arrangement for you disk with 'bad' areas, you can always start from 'scratch' - since afterall - lvm2 ONLY manipulates with metadata within disk front - so if you need to create new 'holes', just 'pvcreate -f', vgcreate, and 'lvcreate -Zn -Wn' and then 'lvextend' with normal or 'lvextend --type error | --type zero' segment types around bad areas with specific size. Once you are finished and your LV precisely matches your 'previous' LV of you past VG - you can start to use this LV again with new arrangement of 'broken zeroed/errored' areas. I've some serious doubts about usability of this with any filesystem :) but if you think this has some added value - fell free to use. If the drive you play with would be 'discardable' (SSD/NVMe) then one must take extra care there is no 'discard/TRIM' anywhere in the process - as that would lose all data irrecoverably.... But good advice from me - whenever 'smartctl' starts to show relocation block errors - it's the right moment to 'dd_rescue' any LV to your new drive... <blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> yes, pvmove is the other approach for that. but will pvmove continue/finish by all means when moving extents located on a bad sector ? </blockquote> pvmove CANNOT be used with bad drives - it cannot deal with erroring sectors and basically gets stuck there trying to mirror unrecoverable disk areas... Regards Zdenek <hr> linux-lvm mailing list linux-lvm@redhat.com <a href="https://listman.redhat.com/mailman/listinfo/linux-lvm">https://listman.redhat.com/mailman/listinfo/linux-lvm</a> read the LVM HOW-TO at <a href="http://tldp.org/HOWTO/LVM-HOWTO">http://tldp.org/HOWTO/LVM-HOWTO</a>/ </pre></blockquote></div></body></html>