>>> On 10/10/2012 at 11:35 AM, "Duerbusch, Tom" <[email protected]> >>> wrote:
> Just speaking to LVM... > > Striping the data across multiple volumes (which in modern dasd is already > stripped in the Raid array), would give you the best performance. > Especially if you can strip across multiple DS8000 (or other dasd > subsystems). > > But you can also use LVM as a pool of DASD, with no striping involved. > > In case 1, if you need to expand the LVM pool, it is a hassle. It might > mean backing up, reformatting and reloading the data. In any case, it > involves a knowledgeable person and most likely, downtime. This is simply not true. Expanding a striped LV can be done dynamically with no downtime. The only aspect that is different from a non-striped LV is that you have to have enough free space on as many different PVs as the number of stripes you have. That is, if you did an "lvcreate -i 2" then when you do an lvextend/lvresize, you have to have free space available on 2 different PVs in the pool. An "lvcreate -i 3" means you need free space on 3 PVs, etc. A lot of people tend to add space to a volume group one PV at a time. If you're using striped LVs, that won't work unless you make sure that the existing PVs have enough free space on them to accommodate additional stripes being allocated. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
