Re: Problem with partially activate logical volume
Ken Bass <[email protected]>
| Newsgroups | gmane.linux.lvm.general |
|---|---|
| Message-ID | <[email protected]> |
Zdenek: thanks. That makes more sense. I will try after (re-)cloning. Give it a day or so. Ken On Aug 5, 2022, 7:03 AM, at 7:03 AM, Zdenek Kabelac <[email protected]> wrote: >Dne 03. 08. 22 v 23:31 Ken Bass napsal(a): >> >> That's pretty much it. Whenever any app attempts to read a block from >the >> missing drive, I get the "Buffer I/O error" message. So, even though >my >> recovery apps can scan the LV, marking blocks on the last drive as >> missing/unknown/etc., they can't display any recovered data - which I >know >> does exist. Looking at raw data from the apps' scans, I can see >directory >> entries, as well as files. I'm sure the inodes and bitmaps are still >there for >> some of these, I just can't really reverse engineer and follow them >through. >> But isn't that what the apps are supposed to do? > >As mentioned by my previous email you shall *NOT* fix the partially >activated >device in-place - this will not lead to good result. > >User should copy the content to some valid storage device with the same >size >as he tries to recover. > >You can 'partially' activate device with "zero" filler instead of >"error" >(see the lvm.conf setting: missing_stripe_filler="...") - this way >you >will just 'read' zero for missing parts. > >Your another 2nd. option is to 'correct' the VG by filling missing PV >with a >new one with preferable zeroed content - so you will not read 'random' >garbage >in places this new PV will fill the space after your missing PV. >Although even in this case - I'd still run 'fsck' on the snapshot >created on >top of such LV to give you another chance of recovery if you will pick >a wrong >answer (since fsck might be 'quite' interactive when doing such >large-scale >repair) > > >> Sorry I haven't replied sooner, but it takes a long time (days) to >clone, then >> scan 16Tb... >> >> So, please any suggestions are greatly appreciated, as well as >needed. >> >> ken >> >> (I know: No backup; got burned; it hurts; and I will now always have >backups. >> 'Nuf said.) > >Before you run your 'fsck' create a snapshot of your newly created >'backup' >and make all the repair actions in the snapshots. > >Once you are 'satisfied' with 'repaired' filesystem you can then >'merge' >snapshot back to your origin and use it. > >Regards > >Zdenek _______________________________________________ linux-lvm mailing list [email protected] https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/