Another note with regards to LVM: with our infrastructure we did some basic IOZone and bonnie++ tests and discovered that use of LVM causes up to a 10% performance hit for I/O operations in relation to using a native partition table. This convenience did not seem to be worth the hit in performance we found.
-Aaron On Mar 10, 2011, at 1:48 PM, Konstantin Olchanski wrote: > On Thu, Mar 10, 2011 at 05:35:30AM -0500, Robert P. J. Day wrote: >> >> first question -- is there any sane reason not to use LVM these >> days? the manual opens (predictably) with showing the student how to >> allocate fixed partitions during the install, and leaves LVM setup for >> later in the week as an "advanced" topic. i see it the other way >> around -- LVM should be the norm nowadays. >> > > > No reason to use LVM. The traditional "md" software raid is much simpler > and easier to manage (only one tool to learn - mdadm, compared > to the 100 lvm management programs). Historically, LVM is a knock-off > of XLV which was the companion partitionning tool to SGI's XFS filesystem. > > >> thoughts? i'll always allocate /boot as a regular partition but >> unless there are compelling reasons not to, i always recommend LVM as >> the standard. > > > Your /boot partition has to be mirrored across both of your system disks. > If it's only on one disk and it fails, you have an unbootable machine, > regardless of what tool you used (lvm or md). > > With "md" it is very simple, /dev/md0 is the system partition mirrored > across /dev/sda1 and /dev/sdb1, there is no need for separate /boot > partition, GRUB happily installs on both /dev/sda and /dev/sdb, and > your machine happily boots if either disk explodes. > > To do the same with LVM, you probably have to read a book and take > an advanced sysadmin class; and forget about getting it to actually > work without the help of this mailing list. > > > -- > Konstantin Olchanski > Data Acquisition Systems: The Bytes Must Flow! > Email: olchansk-at-triumf-dot-ca > Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada
