Vinum deprecation for FreeBSD 14 - are there any remaining Vinum users?

[Doug Ambrisko]

On Thu, Apr 01, 2021 at 11:20:44AM +0300, Lev Serebryakov wrote:
| On 01.04.2021 2:39, Doug Ambrisko wrote:
| 
| > | > I can only state that I use it only occasionally, and that when I do. I
| > | > have had no problems with it. I'm glad that it's there when I need it.
| > |
| > | Thanks for the reply. Can you comment on your use cases - in
| > | particular, did you use mirror, stripe, or raid5? If the first two
| > | then gmirror, gconcat, gstripe, and/or graid are suitable
| > | replacements.
| > |
| > | I'm not looking to deprecate it just because it's old, but because of
| > | a mismatch between user and developer expectations about its
| > | stability.
| > 
| > It would be nice if graid got full support for RAID5 alteast I'm not sure
| > how much the others are used for that are not fully supported (RAID4,
| > RAID5, RAID5E, RAID5EE, RAID5R, RAID6, RAIDMDF) according to the man
| > page.  I started to hack in RAID5 full support and try to avoid writes
| > if members didn't change.  This limits our VROC support.
|   My experience, as co-author and maintainer of `sysutil/graid5`, 
|   shows, that it is very non-trivial task. It contains many subtle
|   problems.
| 
|   `graid5` still has some undiscovered problems, and I don't think it 
|   worth fixing in 2021, when we have ZFS for many years.

The only advantage I see of graid supporting raid5 would be better support
for VROC and people like RAID5.  I don't like RAID5 for SSD's since it
adds to write amplification issues but people like it.  RAID5 had
terrible write performance in Linux with concurrent I/O.  I wanted to
see if FreeBSD could do better.

Intel seems to be pushing VMD since we recently had a FreeBSD user
need newer VMD support since they couldn't turn it off in the BIOS.
VMware doesn't support VROC.  We support it a bit in that VMD allows
graid to access the drives and deals with the Intel meta data.  It
doesn't read the info. from the EFI runtime.  So in RAID 0, 1 and 10
should work.  It would be nice if someone could install FreeBSD on
working Linux config.  No-one has asked for it so it doesn't seem
very important.

Thanks,

Doug A.