From: David Hull (David_Hull@Jabil.com)
Date: Mon Feb 03 2003 - 09:00:54 EST
I'm not experienced with LSM, but I've already RTFM and gotten some
pointers, still I'm having capacity issues (aren't we all? :). I've got an
external 7-slot storage unit attached to an Alpha workstation running 5.1.
I've got 6 18GB drives in it from which I'm trying to create a RAID5 array.
I've added all of the disks to the LSM rootdg, as evidenced by:
# voldisk list
DEVICE TYPE DISK GROUP STATUS
dsk0 sliced - - unknown
dsk1d simple - - online invalid
dsk3c simple dsk3c rootdg online
dsk4c simple dsk4c rootdg online
dsk5c simple dsk5c rootdg online
dsk6c simple dsk6c rootdg online
dsk7c simple dsk7c rootdg online
dsk8c simple dsk8c rootdg online
#
(dsk0 is swap and /var, dsk1 is O/S and swap - the rest are in the external
unit) but when I try to creat the RAID5 set, it won't use all of the
capacity. I don't need a hotspare, and I don't think I need logging (at
least, I don't want to lose an entire disk to it - this is not a mission
critical workstation!) If I set in the /etc/default/volassist file
layout=raid5, the maxsize gives me:
# volassist -g rootdg maxsize
Maximum volume size: 71120896 (34727 Mb)
and it will only add 4 of the disks to the RAID5 set, dsk3, dsk4, dsk5, and
dsk6.
If I change the /etc/default/volassist file to layout=raid5,nolog, then I
get:
# volassist -g rootdg maxsize
Maximum volume size: 142243840 (69445 Mb)
Without any options in the /etc/default/volassist file, I get:
# volassist -g rootdg maxsize
Maximum volume size: 213364736 (104182 Mb)
And that's more like it - so it's seeing all the drives, but creating a
RAID5 set from them severely reduces my effective capacity - more than just
losing 1 drive to parity.
I've tried creating another disk group, but that didn't seem to work. So,
can someone shed some light on what I'm doing wrong here, please?
Regards,
David Hull
SAP Basis Administrator
Jabil Circuit, INc.
+1.727.803.3855
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