[sclug] Partitioning schemes

[Will Dickson]

Alex Butcher wrote:

> Here's my filesystem layout:
> 
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/Volume01/root     4031680   1453764   2373116  38% /
> /dev/md0                 99470     55082     39252  59% /boot
> /dev/md1                 99470      4127     90207   5% /boot-spare
> /dev/Volume01/home     3048336   2545360    348148  88% /home
> /dev/Volume00/opt      1032088    881024     98636  90% /opt
> none                    257332         0    257332   0% /dev/shm
> /dev/Volume01/scratch
>                       17091652  15171028   1226272  93% /scratch
> /dev/Volume00/tmp      1032088     35452    944208   4% /tmp
> /dev/Volume00/usr      6128320   5504264    375020  94% /usr
> /dev/Volume01/usrlocal
>                        6379400   6107008     13200 100% /usr/local
> /dev/Volume00/usrsrc   4128448   3608940    435624  90% /usr/src
> /dev/Volume00/var      1032088     93892    885768  10% /var
> /dev/Volume01/varlib    396672    174695    201497  47% /var/lib
> /dev/Volume01/varspool
>                        1007896    807524    149172  85% /var/spool
> /dev/hde1              4087964   2174940   1913024  54% /dosc
> /dev/hdg1              4087964   2121476   1966488  52% /dosd
> /dev/hde7              8175980   6180892   1995088  76% /dose
> /dev/hdg7              8175980   7618972    557008  94% /dosf
> 
> This is a system running RH8, plus booting to W98 for games and hardware
> setup occasionally. Note that I'm using both RAID0 and RAID1 over the two
> discs, /dev/hde and /dev/hdg. I've rather craftily got two 40G partitions
> RAID1'd (mirrored) and two 15G partitions RAID0'd (striped). I run LVM on
> top of them (giving /dev/Volume01 and /dev/Volume00, respectively) so that I
> can dynamically re-allocate space between partitions on those volumes as
> demand shifts. Important stuff (/home, /var/spool, ...) is on filesystems
> contained within the RAID1 volume group, and less important stuff (/usr,
> /tmp, ...) is on the RAID0 volume group. If a disc dies, I've got a system
> rebuild to do, but at least my data should be safe. If I had more disc
> space, I'd go solely with RAID1.

Whoa! That all looks a bit hairy for me :-) What 
filesystem(s) do you use? The reason I ask is that, unless 
I've completely got the wrong end of the stick, you need to 
be able to resize the filesystem in order for LVM to be of 
use, and resize_reiserfs is still marked as beta. Granted, 
that group seem very conservative about their code quality, 
so their beta is probably equivalent to some other 
organisations' gold (or service pack 1), but even so.

> 
> 
> Life's too short for statically-sized partitions. If you've only got a
> single-user machine, don't want to use LVM, and don't mind doing a full
> backup/restore during OS upgrades, then a large / is probably the next best
> thing.

How does LVM save me having to do backup/restores during OS 
upgrades?

Ta,

Will.