On Thu, 14 Apr 2011 11:57:47 +0400 CoolCold <coolthecold@xxxxxxxxx> wrote: > On Thu, Apr 14, 2011 at 12:55 AM, David Brown <david.brown@xxxxxxxxxxxx> wrote: > > On 13/04/11 22:21, David Miller wrote: > >> > >> From: "Matthew Tice"<mjtice@xxxxxxxxx> > >> Date: Wed, 13 Apr 2011 13:38:39 -0600 > >> > >>> So of course it technically doesn't matter but are there certain > >>> (non-apparent) repercussions for choosing one over the other? It seems > >>> to > >>> save a couple steps by using the whole disk (not having to partition) - > >>> but > >>> is that it? One thing I'm thinking about the pros of using partitions is > >>> if > >>> all your disks (or some) are different sizes - then you can set the > >>> partition sizes the same. > >> > >> First, you sent this to "linux-raid-owner" instead of just > >> "linux-raid". The former goes to me, not to the mailing list. > >> > >> I've corrected it in the CC: > >> > >> Second, to answer your question, for some disk label variants you > >> risk over-writing the disk label if you use the whole device > >> as part of your RAID volume. This definitely will happen, for > >> example, with Sun disk labels. > > > > Using whole disks in the raid will make it easier for replacing disks - you > > don't have to worry about partitioning them. You can just plug them in and > > use them. If you have some sort of monitoring scripts and hot plug disks, > > you may be able to avoid any interaction at all on disk replacement. > > > > On the other hand, using partitions gives you lots more flexibility. You can > > do things such as use a small partition on each disk to form a raid10 array > > for swap, while using a bigger partition for data. Or perhaps you want a > > very small partition on each disk as a wide raid1 mirror, for your /boot > > (not that you need so much safety for /boot, but that it's easier to boot > > from a raid1 with metadata format 0.90 than from other raid types). > Just my 2 cents: I've faced problems when newer disk was smaller than > old disk two or three times, so using partitions now with setting some > free space at the end - something near 80 or 100 megabytes. You don't need partitions to do this. Just use the --size option to mdadm. NeilBrown > > If your system is located on the same disks which holds useful data, > it might be useful to split data into another mountpoint/block device > and let system skip fs check on startup and produce booted server, > which is helpful in case of system crash/powerloss and dirty > fs/breaked raid. RAID assembly problems may be caused by crappy > controller like lsi 1068e which was hanging the whole system and > desync data writes on disks on SMART request or completely on it's > own. > > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
