Re: Two systems -- supposed to be the same, but booting with grub differently. What'd I miss?

[Andrei Borzenkov]

13.04.2017 16:13, address@hidden пишет:
> Hi,
> 
> I've got two machines. Both are supposed to be configured the same: Linux, 
> with grub2 booting, with everything on a RAID-1 array.
> 
> I read up on list posts, docs, etc and got both systems booting up OK, and 
> everything seems to run fine.
> 
> BUT ... "System 2" takes a very long time to boot -- it stalls at right after 
> the Grub menu for up to 2 minutes, then continues to boot normally.  OTOH, 
> "System 1" continue boot immediately.
> 
> I used "bootinfoscript" to look at the grub info for both systems.
> 
> 2 things popped out at me:
> 
>       -- system 1's "/boot" partition is on a RAID array config'd as v1.0 
> metadat; system 2's is v1.2
>       -- system 1's got Grub2 installed in BOTH MBR & boot sector of both 
> RAID disks; system 2's got it only installed in MBR.
> 
> So a couple of questions:
> 
> (a) how SHOULD grub2 be installed in this config?  MBR &/or boot sector?

MBR. You actually cannot install grub2 in partition in this
configuration, at least using grub2 native tools.

> (b) whatever way it should be installed, how do I change the 'wrong on' to be 
> correct?
> 

Just install it in MBR. How to make it persist depends on your distribution.

> What did I miss or forget?
> 
> JerryG
> 
> p.s.  Here's the bootinfo script output that I'm talking about for each 
> system.
> 
> (1) System1
> ------------------------
> cat /proc/mdstat
>       Personalities : [raid1]
>       md1 : active raid1 sda2[0] sbd2[1]
>             487205888 blocks super 1.2 [2/2] [UU]
>             bitmap: 1/4 pages [4KB], 65536KB chunk
> 
>       md0 : active raid1 sbd1[1] sda1[0]
>             1048512 blocks super 1.0 [2/2] [UU]
>             bitmap: 0/1 pages [0KB], 65536KB chunk
> 
>       unused devices: <none>
> 
> mount | grep boot
>       /dev/md0 on /boot type ext4 (rw,noatime,data=ordered)
> 
> 
> cat /root/RESULTS.txt 
>                 Boot Info Script 0.75      [14 November 2016]
> 
> 
> ============================= Boot Info Summary: 
> ===============================
> 
>  => Grub2 (v1.99-2.00) is installed in the MBR of /dev/sda and looks at 
> sector 
>     1 of the same hard drive for core.img, but core.img can not be found at 
>     this location.
>  => Grub2 (v1.99-2.00) is installed in the MBR of /dev/sdb and looks at 
> sector 
>     1 of the same hard drive for core.img, but core.img can not be found at 
>     this location.
> 

Could you make full output available (pastebin or similar)? What
distribution do you use? Could you send me content of post-MBR gap from
both sda and sdb (assuming it is 1MB - dd if=/dev/sda bs=1M count=1
of=sda.mbr)?

> sda1: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  Grub2 (v1.99-2.00)
>     Boot sector info:  Grub2 (v1.99-2.00) is installed in the boot sector of 
>                        sda1 and looks at sector 290367 of the same hard drive 
>                        for core.img, but core.img can not be found at this 
>                        location.
> 
> sda2: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  -
>     Boot sector info: 
> 
> sdb1: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  Grub2 (v1.99-2.00)
>     Boot sector info:  Grub2 (v1.99-2.00) is installed in the boot sector of 
>                        sdb1 and looks at sector 290367 of the same hard drive 
>                        for core.img, but core.img can not be found at this 
>                        location.
> 
> sdb2: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  -
>     Boot sector info: 
> 
> ------------------------
> 
> 
> (2) System 2
> ------------------------
> cat /proc/mdstat
>       Personalities : [raid1]
>       md0 : active raid1 sda1[0] sdb1[1]
>             1047552 blocks super 1.2 [2/2] [UU]
>             bitmap: 0/1 pages [0KB], 65536KB chunk
> 
>       md1 : active raid1 sda2[0] sdb2[1]
>             975581888 blocks super 1.2 [2/2] [UU]
>             bitmap: 1/8 pages [4KB], 65536KB chunk
> 
>       unused devices: <none>
> 
> mount | grep boot
>       /dev/md0 on /boot type ext4 (rw,noatime,data=ordered)
> 
> cat /root/RESULTS.txt 
>                 Boot Info Script 0.75      [14 November 2016]
> 
> 
> ============================= Boot Info Summary: 
> ===============================
> 
>  => Grub2 (v1.99-2.00) is installed in the MBR of /dev/sda and looks at 
> sector 
>     1 of the same hard drive for core.img, but core.img can not be found at 
>     this location.
>  => Grub2 (v1.99-2.00) is installed in the MBR of /dev/sdb and looks at 
> sector 
>     1 of the same hard drive for core.img, but core.img can not be found at 
>     this location.
> 
> sda1: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  -
>     Boot sector info: 
> 
> sda2: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  -
>     Boot sector info: 
> 
> sdb1: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  -
>     Boot sector info: 
> 
> sdb2: 
> __________________________________________________________________________
> 
>     File system:       linux_raid_member
>     Boot sector type:  -
>     Boot sector info: 
> 
> ------------------------
> 
> 
> _______________________________________________
> Help-grub mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/help-grub
>