Am 2010-12-10 16:41, schrieb Volker Armin Hemmann: > 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.
ok .... hmmm > There is no need for lvm with bind mounting and ln -s. I don't fully get that yet ... >>> 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. Ah, yes, already found that and I will check that out soon. Thanks!
