François Patte writes > I would like to change my linux install and I need to modify /home which > is now like this: > > __________________________|__________ > sdc1 sdb2 = 4126 extends > > If I reduce /home by 4127 extends may I be sure that /home will now stay > on sdc1 only? > I am not an expert. Here is a set of instructions how to do it, step-by-step. I have used them in the past. The aim, I understand is to set up a logical volume for /home, that contains no other disk than sdc1. Let /dev/sdc1 be 100 gibabytes large, for illustration 1. check your volume. Say, it's called vg1-lv1, and say it's ext2 or ext3 e2fsck -f -y /dev/mapper/vg1-lv1 2. resize the file system resize2fs -pf /dev/mapper/vg1-lv1 100G where 100 is the size of home, assumed here. That resizes the file system with ext, of course, if you use another file system type there will be another command. 3. reduce the logical volume lvreduce -L 100G /dev/vg1/lv1 4. Now look at pvdisplay 5. If sdb2 is 0% used, go to step 6, else run pvmove /dev/sdb2 6 you can now reduce the disk from the volume. vgreduce vg1 /dev/sdb2 > Was it possible to be aware of this before discoring it after > install? I guess this is an issue of the O/S you are using. > What happens if sdb disk crashes? Shall I loose all my data in > /home? Not necessarily. If you find that /dev/sdb2 is getting bad, you get read/write errors, or you perform a badblock check on it, say, you can recover by reducing as described about. I have done this several times with good results. The big problem occurs of the first disk /dev/sdc1 is in a bad shape such that you can not get to the filesystem anymore. This is what happened to me. I still have not fixed my problem, compounded by the fact that this accident occured shortly after I erased my backup by mistake. Unless you are a real disk expert, and you know lvm very well, I would only use lvm for building large disks to hold backup, and only when you are sure you are having two backups. Bonne chance! Thomas Krichel http://openlib.org/home/krichel RePEc:per:1965-06-05:thomas_krichel phone: +7 383 330 6813 skype: thomaskrichel _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
