Re: Custom partition layout corrupts install ? +MFS question

OK, problem solved. Using a 7.5GB ( < 8GB ) root partition
and my custom layout, as well as on-disk /var and /tmp, I no
longer run into this bug. This seems to confirm that it
was due to a too large root partition that corrupts the
bootloader's heap memory ? As suggested elsewhere.

Here is my current, working partition scheme :

# disklabel -p M wd0
# /dev/rwd0c:
type: ESDI
disk: ESDI/IDE disk
label: Samsung SSD 870
duid: 4b245bbda66d568c
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 969021
total sectors: 976773168 # total bytes: 476940.0M
boundstart: 532544
boundend: 976773135

16 partitions:
#                size           offset  fstype [fsize bsize   cpg]
   a:          7680.0M           532544  4.2BSD   2048 16384 12960 # /
   c:        476940.0M                0  unused
   d:          4096.0M         16261184  4.2BSD   2048 16384 12960 # /tmp
   e:         20191.0M         24649760  4.2BSD   2048 16384 12960 # /var
   f:         30720.0M         66000832  4.2BSD   2048 16384 12960 # /usr
   g:        237568.3M        170858432  4.2BSD   4096 32768 26062 # 
/var/www
   h:         61440.0M        657398400  4.2BSD   2048 16384 12960 # 
/usr/local
   i:           260.0M               64   MSDOS
   l:         94504.7M        783227520  4.2BSD   2048 16384 12960 # 
/home

On 2026-08-12 18:19, Sylvain Saboua wrote:
> On 2026-08-12 17:30, Brian Conway wrote:
>>> One thing that might be causing disturbances is that I want
>>> to put /var and /tmp on MFS, because it is said that constant
>>> effort put on an SSD disk might corrupt it faster. This is
>>> actually a question in its own right that I should ask as well:
>>> Is it a better practice with today's system and materials to
>>> put /var, /tmp and maybe others on virtual memory instead of
>>> disk ? Especially for a server that might run 24/7 ?
>> 
>> I can't speak to the errors you're getting (because I don't think you 
>> included them?),
> That's right, I haven't included the errors since this would have 
> required me to film my screen and upload a video. (And even with that, 
> I didn't run into the same errors once I re-installed with the default 
> partitionning anyway). From my (somewhat) extensive research I believe 
> the failure is actually due to an oversized root partition, that 
> apparently corrupts the heap memory of the bootloader. I'll try a 
> custom layout again formatting a < 8GB root partition.
> 
>> but given that the SSD you're using is a Samsung SSD 870 and not 
>> something generic/noname/garbage, I would not put the effort into 
>> moving paritions onto mfs in an attempt to protect disk writes. And I 
>> say that as someone that enjoys slinging around mfs mounts.
> Really, even for a 24/7 server ? I might do that then, as it reduces 
> the hassle.

-- 
Sylvain Saboua
looking for a PDP-11