Am Mittwoch, 9. Mai 2007 schrieb Alfred von Campe: > The recent thread on Anaconda and RAID10 made me start to think about > how to partition a server I'm about to set up. I have two 146GB SCSI > drives on an IBM x3550. It will be used as a build system. As such, > there is no critical data on these systems, as the source code will > be checked out of our source control system, and the build results > are copied to another system. I usually build my systems with > Kickstart, so if a disk dies, I can rebuild it quickly. > > Given all that, how would you partition these disks? I keep going > back and forth between various options (HW RAID, SW RAID, LVM, > etc.). I guess speed is more important to me than redundancy. I'm > tempted to install the OS on one drive and use the entire second > drive for data. This way I can rebuild or upgrade the OS without > touching the data. But that will waste a lot of disk space, as the > OS does not need 146GB. > > The only thing I'm pretty sure of is to put 2GB of swap on each > drive, but after that everything is still in the air. I am looking > for any and all suggestions from the collective wisdom and experience > of this list. Ask yourself this question: Does the company loose money when the build system is down for restore? How much? How long does a restore take? Mirroring disks is not a replacement for backup. It is a way to improve availability of a system (no downtime when a disc dies), so it might even be interesting when there is no important data on the machine. If this is important for you use RAID-1 for the entire discs. If decreased availability is not a problem for you (you can easily afford a day of downtime when a disc dies) use RAID-0 for the entire discs. It will give you a nice performance boost. Especially on a build host people will love the extra performance of the disc array. A combination of RAID-0 and RAID-1 may also be an option: Make a small RAID-1 partition for the operating system (say 20GB) and a big RAID-0 partition for the data. This way you will get maximum performance on the data partition, but when a disc dies you do not need to reinstall the operating system. Just put in a new disc, let the RAID-1 rebuild itself in the background and restore your data. This can reduce the downtime (and the amount of work for you) when a disc dies considerably. HW vs SW RAID: Kind of a religious question. HW has some advantages when using RAID-5 or RAID-6 (less CPU load). When using RAID-0 or RAID-1 there should not be any difference performance wise. HW RAID gives you some advantages in terms of handling, i.e. hotplugging of discs, nice administration console, RAID-10 during install ;-), etc. It's up to you to decide whether it is worth the money. Plus you need to find a controller that is well supported in Linux. regards, Andreas Micklei P.s. Putting lots of RAM into the machine (for the buffer cache) has more impact than RAID-0 in my experience. Of course that depends on your filesystem usage pattern. P.p.s. Creating one swap partition on each disc is correct, because swapping to RAID-0 is useless. Only if you decide to use RAID-1 for the whole disc you should also swap to RAID-1. -- Andreas Micklei IVISTAR Kommunikationssysteme AG Ehrenbergstr. 19 / 10245 Berlin, Germany http://www.ivistar.de Handelsregister: Berlin Charlottenburg HRB 75173 Umsatzsteuer-ID: DE207795030 Vorstand: Dr.-Ing. Dirk Elias Aufsichtsratsvorsitz: Dipl.-Betriebsw. Frank Bindel