On Friday 10 December 2010, Stefan G. Weichinger wrote: > Am 09.12.2010 18:21, schrieb Volker Armin Hemmann: > > Put /boot on raid1, / on raid6. Don't bother with lvm - it is just > > another layer that can go wrong. > > You mean "don't use lvm for /" ? ... for other stuff it's very useful, > isn't it?
no, I mean don't use lvm. It is a very compley, easily broken layer reducing data safety. There is no need for lvm with bind mounting and ln -s. > > > If Raid6 is like raid5 you should be > > able to have the kernel auto assemble everything, so no initrd is > > needed. Pay attention to the metadata format when creating the raid. > > Also have a look at stripe sizes. And stripe_cache_size. > > Thanks for your reminders. > What exactly do you think of with stripes and sizes? > You point at the performance-impact? large files vs. small files etc? stripe size has nothing to do with big and small files. But choosing the wrong stripe size can impact your performance very, very badly. We are talking about abysmal performance, Challenger depht abysmal. XFS and ext4 - for both is a lot of documentation available about choosing the right stripe size. stripe_cache_size can be set in /sys and has a 4-5x performance impact on raid5 (where I tried it). A good size for me is 8192. For example.
