On Thursday 24 March 2011 12:19:39 Dale wrote: > J. Roeleveld wrote: > > On Thu, March 24, 2011 12:30 pm, Volker Armin Hemmann wrote: > >> On Thursday 24 March 2011 08:49:52 J. Roeleveld wrote: > >>> On Wed, March 23, 2011 5:43 pm, Volker Armin Hemmann wrote: > >>>> md raid devices can do barriers. Don't know about lvm. But lvm is > >>>> such > >>> > >>> a > >>> > >>>> can > >>>> of worms I am surprised people still recommend it. > >>> > >>> What is wrong with LVM? > >>> I've been using it successfully without any issues for years now. > >>> It does what it says on the box. > >> > >> it is another layer that can go wrong. Why take the risk? There > >> are enough cases of breakage after upgrades - and besides snapshots... > >> is the > >> amount of additional code running really worth it? Especially with > >> bind > >> mounting? > > > > There are always things that can go wrong and I agree, adding additional > > layers can increase the risk. > > However, the benefits of easily and quickly changing the size of > > partitions and creating snapshots for the use of backups are a big > > enough > > benefit to off-set the risk. > > > > Bind-mounting is ok, if you use a single filesystem for everything. I > > have partitions that are filled with thousands of small files and > > partitions filled with files are are, on average, at 1GB in size. > > I haven't found a filesystem yet that successfully handles both of these > > with identical performance. > > When I first tested performance I found that a simple "ls" in a > > partition > > would appear to just hang. This caused performance issues with my > > IMAP-server. > > I switched to a filesystem that better handles large amounts of small > > files and performance increased significantly. > > > > The way I do backups is that I stop the services, create snapshots and > > then restart the services. > > I then have plenty of time to backup the snapshot. > > If I were to do this differently, I'd end up having a downtime for over > > an hour just for a backup. > > Now, it's barely a minute of downtime. > > > > That, to me, is a very big bonus. > > > > -- > > Joost > > I have never used LVM but when it messes up after a upgrade, as has > happened to many others, see if you say the same thing. I hope your > backups are good and they can restore. > > Dale > > :-) :-)
Backups are good and I can restore. Usually need them when I mess things up and accidentally delete files I wanted to keep.... LVM may mess up if something goes wrong, but as the LVM-tools backup the metadata for LVM, it is trivial to restore and I have not lost any data because of issues like that. :) -- Joost
