Re: Software RAID blocks

[Reco <recoverym4n@enotuniq.net>]

On Sun, Jan 13, 2019 at 02:22:09PM +0100, Tom Bachreier wrote:
> 
> Hi Reco!
> 
> Jan 13, 2019, 1:47 PM by recoverym4n@enotuniq.net:
> 
> > On Sun, Jan 13, 2019 at 01:20:50PM +0100, Tom Bachreier wrote:
> >
> >> Jan 13, 2019, 12:46 PM by >> recoverym4n@enotuniq.net <mailto:recoverym4n@enotuniq.net>>> :
> >>
> >> > On Sun, Jan 13, 2019 at 12:27:19PM +0100, Tom Bachreier wrote:
> >> >
> >> >> TLDR;
> >> >> My /home on dmcrypt -> software Raid5 blocks irregular usually without
> >> >> any error messages.
> >> >>
> >> >> I can get it going again with "fdisk -l /dev/sdx".
> >> >>
> >> >> Do you have an ideas how I can debug this issue further? Is it a dmcrypt,
> >> >> a dm-softraid or a hardware issue?
> >> >>
> >> >
> >> > Let's start with something uncommon:
> >> >
> >>
> >> Thanks for your suggestions.
> >>
> >
> > My suspicion is that either some/all HDDs' firmware or disk controller
> > puts drive(s) in sleep mode.
> >
> 
> In this case: Why don't they awake with a write from dm-raid but with
> a read from fdisk? I don't see the logic behind.

RAID5 may be the reason. If you're reading a short sequence of bytes
from the array it does not mean you're utilizing all the drives.


> >> hdparm seems OK. Keep in mind only sdc and sdf ar WD drives.
> >>
> >
> > Since you have Seagates, please check them with 'hdparm -Z'.
> >
> 
> I don't think that did much to my drives.

I agree. It seems that drive's firmware rejected the request.


> $ smartctl -l scterc,70,70 /dev/sdd
> SCT Error Recovery Control set to:
>            Read:     70 (7.0 seconds)
>           Write:     70 (7.0 seconds)
> 

This setting may not survive the powercycle. Happen to have four such
drives. I just apply it at every reboot.

Reco