Raid5:- not booting after removing the first disk that is sda

nitinm · 11-19-2018, 04:00 AM

what should happen if i remove d first drive from raid 5 that is sda.
When i did it my sytem did not boot, but connecting it back physically it boots in and status shows removed.
what should be the problem? Why it does not boot when i disconnect the very first disk even after having 2 more disk in raid?

Thanks

berndbausch · 11-19-2018, 07:39 AM

Without any other information, I would guess that the disk blocks required for booting are not sync’ed to the other disks yet. Or that the BIOS or UEFI expects to boot from sda. Or that any phase in the boot process expects sda to be present.

It would be useful to know how you created the RAID, at what stage does the boot process fail, and what error messages you see.

nitinm · 11-19-2018, 10:43 AM

actually while booting the device sda must be physically connected because the boot loader is in firts disk that is sda.

Thanks

Berndbaush

TenTenths · 11-20-2018, 05:11 AM

Quote:

Originally Posted by nitinm

Why it does not boot when i disconnect the very first disk even after having 2 more disk in raid?

Most likely because you're using a fake/software RAID rather than a proper RAID controller.

nitinm · 11-20-2018, 05:23 AM

Yes i am using software raid

TenTenths · 11-20-2018, 05:31 AM

Quote:

Originally Posted by nitinm

Yes i am using software raid

So you've now discovered one of the fundamental flaws with fake/software RAID, it has a reliance on the boot mechanism to start before the actual "RAID" will work. Keep this in mind before relying on this type of "RAID" for a production environment.

Indeed, I'd go so far as to say that nobody should use this type of "RAID" on anything that's production critical.