My Software RAID 1 was working fine as Long as the two disks were 2TB each.
Upgrading to 4TB disks turned into a nightmare.
I need to use GPT of course with these disks.
The straightforward Approach
remove one of the old disks and build in the new one
create the partitions with FD00 id (RAID)
mdadm /dev/md… -a /dev/sd… and let the system do a resync of the mirror
worked fine overnight.
Then let grub2 write the bootsector of the new disk (yast2 bootloader, enable redundancy for MD array) works fine as well.
Take out the second “old” disk and have the computer restarted.
IT DOES NOT BOOT!
OK, I found that I need a partition /boot/efi and all that stuff.
Now it works with:
GPT fdisk (gdisk) version 0.8.7Partition table scan:
BSD: not present
APM: not present
Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 5860533168 sectors, 2.7 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): 62C8ACD2-3E46-47F2-B99A-B68116C7D645
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 2048-sector boundaries
Total free space is 10658669 sectors (5.1 GiB)
Number Start (sector) End (sector) Size Code Name
1 2048 321535 156.0 MiB EF00 Primary
2 321536 8722431 4.0 GiB FD00 Primary
3 8722432 5849876479 2.7 TiB FD00 Primary
Same for /dev/sdb
/dev/sda1 & /dev/sdb1/ form /dev/md1 serving as swap.
/dev/sda2 & /dev/sdb2/ form /dev/md0 mounted as /.
The /boot/efi (/dev/sda1) is not “raided” - I had to copy it to /dev/sdb1 doing a “dd”.
GRUB issues a message “Perl-Bootloader: 2014-04-01 18:16:43 <3> yast-0309.1 MBRTools::examineMBR.189: Error: Examine MBR cannot open /dev/md” on the command line while you start up “yast2 bootloader”.
No clue what this wants me to tell. Finally there is no MBR with GPT / EFI boot.
There is not way without re-installing from scratch to use larger disks beyond the 2TB if you did use MBR before.
YASTs Support for RAID with GPT is lousy. It is missing a proposal for the RAID partitioning scheme completely.
Anybody with a solution for 1) ?
Anybody with an idea for 2) ?
It is possible to do MBR booting with GPT, and grub installed in the MBR (the protective MBR). You need to create a BIOS Boot partition (“gdisk” type code is EF02, as I recall). It is typically created to use sectors 34-2047.
The issue IS NOT if to EFI boot or to MBR boot.
The issue IS that you need the EF02-type partition (BIOS) or the EF00-type Partition (EFI) which both cannot be “raided”. And one like these you need in any case, EFI or MBR boot.
If you have “zero experience with RAID” why waste your, my and our time with your posting?
Sorry, I do not want to be rude, but it is annoying to get replies wthout any substance.
Sorry, but when you do not want to be rude, then you better do nothing that is even near to it.
All people here try to help as good as they can. Sometimes this is more straightforward then at other opportunities, but it is never to spoil your time. People try to gather information and to give information in the hope that a common action might be usefull.
And about spoiling time. You spoil our time by not even telling in the first place which version of openSUSE you use.
What I did on one system of mine was boot from an SD card with just /boot and leave the system as mbr with the raided disks gpt, then set the system to boot via the sd card. You could also use a usb device instead, either method adds minimal delay to the system booting.
You have got a point there.
As you can see from my location English is not my mother language.
I might have lacked to notice that something which is absolutely political correct if expressed in German may have a tendency to rudeness if expressed in another language. I promise to care about that from now on.
With the two posts here (I am a newcomer to the forum) my experience is, however, that I did not get any reply of some use in spite of the fact that there had been immediate responses.
I could not agree more with your statement that “All people here try to help as good as they can.”
From the major part of the threats here an impression comes up, however, that many posters are extremely superficial, some seem not to have read what was posted or did not have understood.
A reply with the line “zero knowledge about RAID” to a threat which is asking a question about RAID is self-explanatory. (Hope this is now political correct and not rude again).
BTW: I have solved all the problems laid down at the start of my thread in the mean time. Should any one be interested in the solution please let me know.
My system is an openSuSE 13.10 with latest patch levels (188.8.131.52).
You are absolutely right regarding duplicate filesystem UUID. I forgot that after the “dd” “sgdisk -G /dev/sdb1” is needed to create a new (randomized) partition GUID. Your Approach, however, is much better than mine. THANKS!
I have not tried any secure boot yet - I am not using Windows… But your hint is very much appreciated.
**3) Sorry for my stupidness about the kernel parameter. I thought it would pass a reference to /dev/sda which is actually not the case. All the disk swap actions are obsolete because (as you have clarified pefectly) the parameter to the kernel is referening /dev/m1. So this can remain identical on both disks.
**Thanks for your explanation about “shouting in the Forum”, “feature request” etc. Unfortunately I am not familiar with either the programming language YAST is written in nor with the YAST implementation itself. So I am afraid I have very little chance to implement the feature by myself. But let me think about it.
My friends call my by name, others call me by value.