Thank you to everyone who responded and contributed to this topic. I appreciate it greatly! On 9/2/2011 12:03 PM, Devin Reade wrote: > You've already received some good responses so I won't rehash a > lot of what was said. However here are few more comments without > a lot of backing detail (but it should give you enough info to > google for detail): > > 1. Despite the RedHat link someone provided, I think the advice of > putting almost everything on the root filesystem is a lot of > bunk, at least for servers. The old arguments for separate > filesystems still apply. I suspect that the single filesystem > perspective is coming from desktop scenarios, and especially > laptop users and those coming from MS Windows. > > 2. Putting /boot on its own filesystem and using LVM for everything > else is a generally good idea from both the management and > snapshot perspectives as someone previously described. However be > aware that most (if not all) LVM configurations will disable > write barriers -- this is probably mostly of interest for when > you're running a database. You need to put on your combined > DBA and sysadmin hat, have a look at your underlying disks, > disk controller, filesystem stack, database, UPS/powerfail > monitoring, and budget to see where your balancing point is. > Yes, I have databases on LVM on top of RAID on top of SATA; > but it's better to know your risks rather than having them > be a surprise. > > 3. Pay attention to whether your disks are using the old 512 byte > sector size or the new 4k sector size (sometimes called advanced > disk format), and whether or not your disks lie to the OS about > the sector size. The RAID, other MD layers, and filesystem > need to know the truth or you can run into performance and/or > lifespan issues. > > 4. Regarding swap: Yes, having it is still a good idea under most > circumstances. The old "2 * physical memory" rule no longer applies. > Follow the sizing guidelines from RedHat that someone posted. > The kernel is smart enough to use it when necessary and avoid it > otherwise. Having it can get your server through unusual circumstances > without crashing but you should have enough memory that you're not > paging under normal circumstances. See also point #6. > > 5. Consider encrypting swap. See crypttab(5), including the comments > about using /dev/urandom for the key. > > 6. Putting /tmp on tmpfs is a good idea in that it ensures that it > gets cleaned out at least when the system reboots. (Running cron > jobs to clear it out periodically can cause problems; under some > circumstances.) This is a good argument to have swap; you can > use tmpfs without a significant impact of /tmp using up physical > RAM. Also see the 'tmp' option in crypttab(5). > > 7. Under CentOS 5 having less than 2G for /var could cause problems > with updates, especially between minor versions. I've increased > my minimum to 4G under RHEL6 due to kdump concerns. > > Devin > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos