Re: 16 HDDs too much for RAID6?

[Andre Noll <maan@systemlinux.org>]

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On 11:55, Lars Täuber wrote:
> monosan:~ # cat /etc/mdadm.conf 
> DEVICE partitions
> ARRAY /dev/md2 level=raid1 UUID=d9d31de2:e6dbd3c3:37c7ea09:882a64e5
> ARRAY /dev/md3 level=raid1 UUID=a8687183:a79e514c:ca492c4b:ffd4384f
> ARRAY /dev/md4 level=raid6 num-devices=16 UUID=8d596319:4d21dba3:3871bccf:5b90a66d

Does it help to list only the 16 devices that are used for the array,
i.e. something like

	DEVICE /dev/sd[a-p]
	
> sdz and sdj are the same physical device with serial 5QJ02461 called /dev/dm-8:
> rename: mpath9 (SATA_ST31000340NS_5QJ02461) dm-8 ATA     ,ST31000340NS  
> [size=932G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=0][active]
>  \_ 6:0:24:0 sdz  65:144 [active][ready]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 6:0:7:0  sdj  8:144  [active][ready]
> 
> similar to sdy and sdi with serial 5QJ013GW called /dev/dm-9
> reload: mpath10 (SATA_ST31000340NS_5QJ013GW) dm-9 ATA     ,ST31000340NS  
> [size=932G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=0][active]
>  \_ 6:0:23:0 sdy  65:128 [active][ready]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 6:0:6:0  sdi  8:128  [active][ready]

I think this is what is confusing mdadm. Your "DEVICE partitions"
line instructs mdadm to consider all devices in /proc/partitions,
so it finds both sdy and sdi.

> Is there a way to get more verbose infos or debug this anyhow?

There's the --detail and --verbose command line options to mdadm.

Andre
-- 
The only person who always got his work done by Friday was Robinson Crusoe

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