Centos7 Server with Raid5 Array(3Disks) does not start any more

[ghainz]

Hello,
I am a beginner regarding Linux.
I own a Dell T20 Server with an 250GB SSD and a 3 disk Raid5 array with 4TB each.
After a centos update I restartet the server but it did not really start, it showed an emergency screen, where I can login.
I copied the startup log with the help of you.
I attach it because it is too big to copy it intothis text.


Please help me to repair it, if this is possible.
Thanks

[TrevorH]

Pick the older kernel from the grub menu and see if that works. If it does then check you have free space on /boot and then yum reinstall the latest kernel.

[ghainz]

I did that but it started to the emergency screen.
Boot has 50G, 39G are free.

[TrevorH]

You need to look through the console log for errors. Use Shift-PgUp to scroll the output.

[ghainz]

I thought I attached the console log in my first post, but it was too big.
So I now send a zipfile.
As a beginner I have no idea where to search.

So here it is:

abcd.zip

(20 KiB) Downloaded 94 times

[TrevorH]

That's from 2 days ago and is unlikely to be the current log as everything I could see there is working. If it won't boot then it probably can't write to that log either so you need to use the console.

[ghainz]

I again started the server today and it took a while, first it showed for some time the light green screen with the 7 on it.
Then the emergency screen appeared.
There I found the command:"journalctl -xb" to view the console start messages. I redirected them to abc1.txt.
I hope this helps.
Here it is:

abc1.zip

(19.69 KiB) Downloaded 56 times

[TrevorH]

Sep 14 11:43:28 centos systemd[1]: Job dev-md0.device/start timed out.
Sep 14 11:43:28 centos systemd[1]: Timed out waiting for device dev-md0.device.

Your md device appears to be showing up as md127 not md0. If you reference it in /etc/fstab by device name - /dev/md0 - then I would suggest changing that to use either LABEL= or UUID= so that the device name can change as it feels.

[ghainz]

you are right, it was: /dev/md0 /Raid5_Data ext4 defaults 1 2
I wanted to use the LABEL entry for fstab, but what is the label of the 3 disks?
There are also 3 UUIDs .
I am stuck.

[TrevorH]

Run blkid