On Sat, August 8, 2009 11:11 am, Goswin von Brederlow wrote: > Tapani Tarvainen <raid@xxxxxxxxxxxxxxxxxx> writes: > >> On Thu, Aug 06, 2009 at 08:08:47PM -0400, Harold Pritchett >> (harold@xxxxxxx) wrote: >> >>> Mirrored Linux Mini How-to >> >> A few quick observations: >> >>> Install linux on two identical disk drives in such a way that the >>> failure >>> of either of the drives will allow the system to be recovered without >>> any >>> loss of data >>> >>> Both of the drives are partitioned exactly the same: >>> 1. 3 primary partitions >>> 2. Partition 1 - size - 1GB format as Linux Raid (fd) >>> 3. Partition 2 - size = real memory size, format as linux swap >>> (82) >>> 4. Partition 3 = size = remainder of disk, format as linux raid >>> (fd) >> >> If I read correctly, you are not only leaving swap out of lvm, >> you are not mirroring it at all - which would make the system >> crash if the swap disk breaks. >> Putting swap on lvm would also allow growing it easily as needed. > > On the other hand don't forget that raid1 is buggy with swap and the > page contents might change between writes to the first and second > disk. Or has that been fixed? There is no bug here. The behaviour is a little unexpected but it is perfectly "correct" in that there is never any risk to data. NeilBrown > >> Another point is that sometimes it is useful to have multiple >> partitions separately mirrored and then combined with lvm: >> it allows things like changing the raid configuration from >> two-disk raid1 to three-disk raid5 without moving data >> via backup and yet avoiding windows of vulnerability >> to single-disk failure during the transition. >> (Perhaps not common enough to be worth mentioning here, >> but I've found it useful.) > > You can transform raid1 to raid5 without loss of redundncy so I don't > quite see what you mean here. > > MfG > Goswin > -- > 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
