Re: Installing grub2 with /boot on software raid

[Wesley PA4WDH]

Hi All,

Since i don't have any clue on how to troubleshoot this any further, i started 
reading the grub source code.
As far as i can see it scans partitions at boot time to detect all partitions 
and devices. Is there a place where i can limit it to only scan /dev/sda1, 
/dev/sda2, /dev/sdb1 and /dev/sdb2 ?
Since i don't need any of the other devices at boot time it doesn't make sense 
to scan them and i don't want any of those device to influence the boot 
stability as it does now.

Best regards,
Wesley




----- Original Message -----
> From: Wesley PA4WDH <address@hidden>
> To: help-grub <address@hidden>
> Cc: 
> Sent: Tuesday, July 16, 2013 10:01 PM
> Subject: Re: Installing grub2 with /boot on software raid
> 
> Hi All,
> 
> To be able to troubleshoot this issue i decided to remove the new array's 
> one by one and reboot after a delete to see if it makes a difference.
> That didn't take long, because right after removing md9 only booting already 
> started working again. As soon as i create it again booting fails in the same 
> way as described ealier.
> 
> Just for reference:
> To delete an array i use:
> mdadm --zero-superblock /dev/sda9
> mdadm --zero-superblock /dev/sdb9
> I don't actually delete the partitions, just doing this makes the system 
> boot.
> To create it again:
> mdadm --create -l 1 -n 2 --metadata=0.9 /dev/md9 /dev/sda9 /dev/sdb9
> (and wait for 2 hours for the sync proces :-) )
> 
> 
> Any suggestions on how to proceed ?
> 
> Best regards,
> Wesley
> 
>> ________________________________
>>  From: Wesley PA4WDH <address@hidden>
>> To: help-grub <address@hidden> 
>> Sent: Sunday, July 14, 2013 3:08 PM
>> Subject: Re: Installing grub2 with /boot on software raid
>> 
>> 
>> Hi All,
>> 
>> I just hit a new problem with my setup.
>> 
>> Since boot and root where working fine i started to use the rest of the 
> disk. I created some extra partitions and created raid's from them:
>> 
>> These are the partitions of sda, sdb is the same:
>> Disk /dev/sda: 1000.2 GB, 1000204886016 bytes, 1953525168 sectors
>> Units = sectors of 1 * 512 = 512 bytes
>> Sector size (logical/physical): 512 bytes / 4096 bytes
>> I/O size (minimum/optimal): 4096 bytes / 4096 bytes
>> Disk identifier: 0xf96d7342
>> 
>>    Device Boot      Start         End      Blocks   Id  System
>> /dev/sda1            2048      264191      131072   fd  Linux raid 
> autodetect
>> /dev/sda2          264192     8652799     4194304   fd  Linux raid 
> autodetect
>> /dev/sda3         8652800  1953525167   972436184    5  Extended
>> /dev/sda5         8654848   428085247   209715200   fd  Linux raid 
> autodetect
>> /dev/sda6       428087296   847517695   209715200   fd  Linux raid 
> autodetect
>> /dev/sda7       847519744  1266950143   209715200   fd  Linux raid 
> autodetect
>> /dev/sda8      1266952192  1686382591   209715200   fd  Linux raid 
> autodetect
>> /dev/sda9      1686384640  1953525167   133570264   fd  Linux raid 
> autodetect
>> 
>> Sda3 upto sda9 are new.
>> 
>> These are the md devices from /proc/mdstat:
>> md1 : active raid1 sdb2[1] sda2[0]
>>       4194240 blocks [2/2] [UU]
>> 
>> md5 : active raid1 sdb5[1] sda5[0]
>>       209715136 blocks [2/2] [UU]
>> 
>> md6 : active raid1 sdb6[1] sda6[0]
>>       209715136 blocks [2/2] [UU]
>> 
>> md7 : active raid1 sdb7[1] sda7[0]
>>       209715136 blocks [2/2] [UU]
>> 
>> md8 : active raid1 sdb8[1] sda8[0]
>>       209715136 blocks [2/2] [UU]
>> 
>> md9 : active raid1 sdb9[1] sda9[0]
>>       133570176 blocks [2/2] [UU]
>> 
>> md0 : active raid1 sdb1[1] sda1[0]
>>       131008 blocks [2/2] [UU]
>> 
>> All md5 upto md9 are all formatted with ext3, that not how i want to use 
> them, but i just wanted to make sure there's a valid filesystem on them.
>> 
>> When i reboot i end up in a rescue shell, and this a log such a rescue 
> session:
>> 
>> GRUB loading.
>> Welcome to GRUB!
>> 
>> error: file `/grub2/i386-pc/normal.mod' not found.
>> Entering rescue mode...
>> grub rescue> ls
>> (md/md8) (md/md7) (md/md6) (md/md5) (md/md1) (md/md0) (md/md9) (hd0) 
> (hd0,msdos
>> 9) (hd0,msdos8) (hd0,msdos7) (hd0,msdos6) (hd0,msdos5) (hd0,msdos2) 
> (hd0,msdos1
>> ) (hd1) (hd1,msdos9) (hd1,msdos8) (hd1,msdos7) (hd1,msdos6) (hd1,msdos5) 
> (hd1,m
>> sdos2) (hd1,msdos1) (hd2) (hd3) (hd4) (hd5) (hd6) (hd7) (hd8) (hd9) (hd10) 
> (hd1
>> 1) (hd12) (hd13) (hd14) (hd15)
>> grub rescue> ls (md/md0)/
>> error: unknown filesystem.
>> grub rescue> ls (hd0,1)/
>> ./ ../ lost+found/ grub2/ boot vmlinuz-3.8.13 .keep vmlinuz-3.8.13-64bit
>> grub rescue> set prefix=(hd0,1)/grub2
>> grub rescue> insmod normal
>> grub rescue> normal
>> grub> ls (md/md0)/
>> error: unknown filesystem.
>> grub> insmod mdraid09
>> grub> ls (md/md0)/
>> error: unknown filesystem.
>> grub> ls (hd0,1)/
>> lost+found/ grub2/ boot vmlinuz-3.8.13 vmlinuz-3.8.13-64bit
>> grub> linux (hd0,1)/vmlinuz-3.8.13-64bit $kernel_parameters
>> grub> boot
>> 
>> 
>> $kernel_parameters is a variable i set with all required kernel parameters: 
> root=/dev/md1 console=ttyS0,19200n8 clocksource=hpet
>> 
>> Somehow it's unable to read the md devices, but it is able to read from 
> hd0,1 (the real partition for /boot). I did try to re-install grub2 but that 
> didn't change the behavior.
>> 
>> Any suggestions on how to fix this ?
>> 
>> Thanks in advance.
>> 
>> Wesley
>> 
>> 
>> 
>