Painted into a corner with i386 system and big FS ...

[UFS User]

Thanks for this response - see comments below...




> It appears that this is impossible to fsck - I have nudged up maxdsiz all the way to:
> kern.maxdsiz="3072000000"
> 
> and it's not enough. ?Any larger values cause the system to become unbootable.
> So, my plan is to boot 8.x amd64 FIXIT, and run fsck from the fixit environment.
> The issues I foresee are:
> 
> 1. Do I need to specify a maxdsiz in the 8.x fixit environment, or does this all just autoscale
> these days ?


> It does not autoscale.  You will need to set it manually at the loader
> prompt by entering 'set kern.maxdsiz="3072000000"' then 'boot'.



Ok, great.  And it's the same old process:

Type '?' for a list of commands, 'help' for more detailed help.
OK set kern.maxdsiz="3572000000"
OK boot

Yes ?


> 2. There is only 4 GB of physical in the system ... if I could grow to 3.072 GB process size in
> i386, then all else being equal, I should be able to grow to 3.5 in 8.x FIXIT, right ?


(snip)


>The 3.5GB value you came up with is equally as amusing.  How much you
>actually get greatly varies on hardware details and so on.  Your
>motherboard manufacturer should be able to tell you how much you'll get,
>as long as you provide them a full list of any PCI/PCI-X/PCIe devices
>you have installed in slots, and any system features you have enabled
>(AHCI, on-board SCSI, etc.).



Oh, sorry for the confusion - the installed OS is freebsd i386, BUT the underlying system is in fact a 64bit system.

It is the physical inaccessibility, and other logistical issues that prevent us from just upgrading the entire OS, etc.

So I will boot amd64 FreeBSD 8.x FIXIT, and will be running in a proper amd64 architecture, but the limitation is I
only have 4 GB physical ram.

So I am hoping that, all else being equal, if i386 can only see (from dmesg):

real memory  = 3489071104 (3327 MB)
avail memory = 3414245376 (3256 MB)

then an amd64 system would see (roughly) 500 megabytes more memory than that, and the 3.072 GB process size I get on i386
will then be (roughly) 3.572 on amd64.

A reasonable guess ?

I hope I don't have to swap, but if I do, presumably this will only grow to 3.8 or 4.0 or 4.2 GB in process size, so that's just the last 1/8 of the job
that will be slow...

Thanks again.