> > a) With my three partitions (666.2, 1001.5, 532.6mb each) What can I setup
> > to have the most space total? (Was it RAID 4 or 5 that worked w/ three
> > disks? and would I get access to the ~2 gig total?)
> make a raid0 array with your two smaller parts. the size will me close to
> your big one, so make /dev/md0 and /dev/sdaX (the big one) into /dev/md1
> with raid1.
Thus giving total available space of 1001.5Mb. Also, as the 532.6Mb partition was /,
Tom will have to get into root-RAID and will need to take a small slice out of one of
the partitions (one whose cylinders lie below the 1024 mark) for /boot. And (I think)
he'll need to play with his start-up scripts, as auto-recognition won't be able to
start the RAID-1 array for him. This is one way of providing redundancy, but it
doesn't maximise Tom's space, or provide enough explanation of what is involved.
One thing we need to know from Tom is whether his 3 partitions are on 3 separate
disks. If so, one idea might be to break the 666.2Mb partition into a 532.6Mb and a
131.6Mb partition and the 1001.4 Mb partition into a 532.6Mb, a 131.6Mb and a 334.2Mb
partition. He can put / on a RAID-1 of the 131.6Mb partitions. /usr could go on a
RAID-0 or RAID-5 of the 532.6Mb partitions, depending whether he wants redundancy for
/usr. RAID-0 would give a 1597.8Mb non-redundant array, RAID-5 would give a 1065.2Mb
redundant array. The 334.2Mb partition could be used for something non-essential (say
/usr/src or /var?). In total, this would give around 1500Mb to 2000Mb of storage.
(With this scheme, it will be necessary to take a small chunk out of the (for
example) 131.6Mb partitions for non-RAIDed /boot partitions.)
Of course, this all depends what he wants to do with the machine. If he will be doing
a lot of logging or sending a lot of mail and if this data is vital, then it won't do
to put /var on a non-redundant partition and there may not be room for it all on /.
In this case it might be best to use a RAID-5 of the 532.6Mb partitions as /, and
maybe RAID-0 the 131.6Mb partitions to maximise the remaining space. Or break the
532.6Mb partitions down further so that 2 RAID-0 or RAID-5 partitions can be created
for /usr and /var, with / staying on the RAID-1 of the 131.6Mb partitions. You could
take this even further if you had a lot of users and break each 532.6Mb partitions
into 3 parts to provide arrays for /home as well as /usr and /var. We really need to
know what the machine will be used for.
If the 3 partitions are not on separate disks, we need to know to which disks they
belong in order to make any useful suggestions.
Cheers,
Bruno Prior [EMAIL PROTECTED]
