Re: Deb10 installer can't install grub

[Dan Ritter <dsr@randomstring.org>]

Felix Miata wrote: 
> Andrei POPESCU composed on 2021-03-03 17:50 (UTC+0200):
> 
> > Felix Miata wrote:
> 
> >> To start with, RAID1 is marginally slower than ordinary filesystems on partitions.
> 
> > This is true for some workloads, for others it can be significantly 
> > faster.
> 
> > https://arstechnica.com/information-technology/2020/04/understanding-raid-how-performance-scales-from-one-disk-to-eight/
> 										
> I wrote not RAID, but RAID1, very purposely. I found no mention of RAID1 in any of
> the graphs there, and the subject of RAID1 barely touched, basically describing
> its purely mirror topology and little else. I can't recall any graph there that
> described performance of anything other than single disk, RAID6, and RAID10. Do
> you know of, or can you provide a reference to, any way RAID1 performance can be
> better than single disk?

Sure.

https://calomel.org/zfs_raid_speed_capacity.html

First two lines of the first table of results:

1x 4TB, single drive,          3.7 TB,  w=108MB/s , rw=50MB/s  , r=204MB/s 
2x 4TB, mirror (raid1),        3.7 TB,  w=106MB/s , rw=50MB/s , r=488MB/s 

Which is as theory predicts: slight reduction in write
performance (write being dominated by disk cache -> disk, not
system -> disk cache), and approximate doubling in read
performance.

-dsr-