Am 11.06.2014 22:17, schrieb thegeezer: > On 06/11/2014 07:57 PM, Stefan G. Weichinger wrote: >> looks promising: >> > > awesome. i did have a look through the diff, there are lots of scsi > drivers selected, storage (block) cgroups but i think the crucial factor > was the HZ was set at 100 previously and 1000 now. i guess it has > helped kernel-io though maybe a kernel hacker in here might give a more > authoritative answer
The help suggests to choose 100 for servers ... the 1000 comes from the sysresccd-setup, yes. I wonder if chosing the "Processor Family" also had an influence. And I even wonder more if I have some bad choices in my desktop's kernel as well ;-) it's a grown setup over years ... For now it looks good ... I will configure the current kernel as a fallback kernel and maybe play with some options. >> One big fat hw-RAID10 might be better? >> But losing the wrong 2 drives makes it crash again ... afaik. > yeah you could argue with raid6 you can _only_ lose two disks, whereas > if you lose the right disks with raid01 you can lose 3 and still rebuild. > raid 0+1 (as opposed to raid10, slightly different) gives you great > speed and at least one drive you can lose. > however, you are not protected by silent bit corruption but then you are > using btrfs elsewhere. ... for the OS, yes ... and maybe for the target of virt-backup. > myself i would use lvm to partition and then at least you can move > things around later; btrfs lets you do the same afaiu > _always_ have your hotspare in the system, then it takes less time to > come back up to 100% > nothing is quite as scary as having a system waiting on the post and a > screwdriver before rebuild can even start good suggestion, sure. That would mean rebuilding the arrays to a RAID6 over 4 or 5 disks and keeping one aside. >> time for a break here. > i'd strongly recommend such monitoring software as munin to have running > -- this way you can watch trends like io times increasing over time and > act on them before things start feeling sluggish I will take a look into it and check how much time I need to learn and set up. > well earned break :) ;-) S
