raid6 problem.

[gene heskett]

On 8/8/25 20:11, Robert Heller wrote:
> Ok, if the volume group is vg0 and the volume name is myraid, then there
> should be a device
>
> /dev/vg0/myraid,
>       ^    ^--- logical volume
>       |----- Volume group
This turned out to be a symlink to /dev/dm-10.
>       
> OR
>
> /dev/mapper/vg0-myraid
>
> is another path to the same place.
Except: ls /dev/mapper (uts a big raid, 5 ea 4TiB drives)
control     vg0-myraid_rimage_0  vg0-myraid_rimage_2 
vg0-myraid_rimage_4  vg0-myraid_rmeta_1  vg0-myraid_rmeta_3
vg0-myraid  vg0-myraid_rimage_1  vg0-myraid_rimage_3 vg0-myraid_rmeta_0  
  vg0-myraid_rmeta_2  vg0-myraid_rmeta_4

>
> (There is another option under /dev/disk/by-id as well.)
>
> so assuming you did something like (creating a Ext4 file system)
>
> sudo /sbin/mkfs.ext4 /dev/vg0/myraid
I switched to mkfs.gfs2 -p lock_nolock before that would proceed where 
it made over 43xxx entries, culminating in:
root at amanda:~# mkfs.gfs2 -p lock_nolock /dev/vg0/myraid
/dev/vg0/myraid is a symbolic link to /dev/dm-10
This will destroy any data on /dev/dm-10
Are you sure you want to proceed? [y/n] y
Discarding device contents (may take a while on large devices): Done
Adding journals: Done
Building resource groups: Done
Creating quota file: Done
Writing superblock and syncing: Done
Device:                    /dev/vg0/myraid
Block size:                4096
Device size:               10752.00 GB (2818572288 blocks)
Filesystem size:           10752.00 GB (2818572253 blocks)
Journals:                  1
Journal size:              1024MB
Resource groups:           42974
Locking protocol:          "lock_nolock"
Lock table:                ""
UUID:                      39a76260-c304-4c90-a6a8-ec89407fd2b3
> sudo mkdir /myraid
ok.
> /etc/fstab could then have
>
> /dev/vg0/myraid /myraid ext4    defaults        1 2
/dev/vg0/myraid  gfs2 defaults  1 2
>
> Even better (hardwiring /dev/... in /etc/fstab is to be avoided whenever
> possible -- using LABEL=r UUID= is prefered to avoid boot time "crashes" due
> to hardware changes):
>
> sudo /sbin/mkfs.ext4 -L MyRaid /dev/vg0/myraid
> sudo mkdir /myraid
>
> then in /etc/fstab:
>
> LABEL=Raid  /myraid ext4    defaults        1 2
I put LABEL=Raid /myraid  gfs2  defaults  1 2

trying to do this but there's no LABEL. I forgot to add it to mkfs.gfs2, 
in fact it doesn't have the -L name option. the doc says tune2fs can do 
that, but how isn't clear.  Hints plz?

Thank you Robert Heller
> At Fri, 8 Aug 2025 17:29:03 -0400 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
>
>> Got Q for admin types, I trying to run amanda on a bpi-m5.
>>
>> I have created this raid6 on arm64 but can't seem to concoct a mount
>> recipe for /etc/fstab.
>>
>> I have this:
>> root at amanda:~# lvs
>>     LV     VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log
>> Cpy%Sync Convert
>>     myraid vg0 rwi-a-r--- 10.50t 2.16
>>
>> I have this seemingly done, lvm and mdadm are all installed.
>>
>> Can anyone help?
>>
>> Thank you.
>>
>> Cheers, Gene Heskett, CET.
>

Cheers, Gene Heskett, CET.
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