Re: [opensuse] Questions for Partitioning guru's
On Thu, 2007-09-13 at 00:47 -0400, Bob S wrote:
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I am interested/concerned about LVM and have a few questions for you.
Besides what the other posts said I didn't see anyone with a setup similar to mine. I'm using 3 disk (was using 5 for a while, 3 ide & 2 sata) and at my peak I had MS Win, opensuse 10.0, 10.1, suse desktop beta and 2 versions Mandrake installed.
You could do something like:
disk1p1 M$ Win disk1p2 /boot # 200Mb common boot for everyone disk1p3 swap # swap common to everyone
OK those first 3 are primary partitions, correct? I understand the concept of the swap for all OS's /boot for everyone? Correct
disk1p5 / # everyday Linux 1 (one you can fall back to) disk1p6 / # everyday Linux 2 (one you plan to move to) disk1p8 LVM disk2p1 LVM disk3p1 LVM
Now these are logical on an extended partition right? P5 & 6 are "regular" e.g. ext3, whatever. The rest of disk one becomes LVM and you put LVM on the remaining disks. yes. I keep around enough non-lvm stuff to be able to run single user mod somewhere but that's about it.
LVM: collection of all partitions marked LVM (=all disks become one huge virtual disk)
Right, now when I installed 10.0 I used LVM. It was fine. When I went to install 10.2 I was going to use LVM again but when I saw that it was going to combine the new volumes with the old ones it frightened me and I backed out used the standard partitioning scheme. Now,since you seem to have everything mixed together, how do you uninstall anything? lvremove /dev/vg/s102lv lvremove /dev/vg/s102varlv lvremove /dev/vg/s102usrlv
It must be a mess. And how about naming volumes, they all have to be unique no? So what does /etc or /var or whatever become when you install. Or do you just make disk1p5 and disk1p6 large enough to hold everything? And what about ubuntuor fedora or whatever. They all have /home, /var, etc. etc. If you think about it, it's not that much different then when using plain partitions. When you have one disk you are forced to call every partition sda1, sda2 and so on up to sda15. If you now install 4 different os versions, how do you keep track of what partition that is /var for each os? With lvm you have the flexibility to name each "partition" something more meaningful so where you now have "sda13" you can name it "s103b3varlv".
homelv # common home dir for all installs (see note above) datalv # common data like install packages, mp3, movies etc NLDlv # root partition for NLD testing SLESlv # root partition for SLES testing fclv # root partition for fedora testing
A common /home? for everything?
You could but may need to keep the users separated so you don't get config files mixed up. I have /home common between everything inlcuding M$ win but that's done by NFS/samba fs on a separate server (which also runs ldap for accounts) so I need to keep track of what user I have for different distro tests. What I end up doing is that for my "stable" day2day use I use my nfs home and when I want to test some other distro I create a small /home for that distro (many times left on / since I don't put anything of value in my test env).
I can see a common /data because that is all it is. And then is accesible from anything you have installed. Good.
<SNIP>
and you can even add a new disk and expand it without problem. If I need to replace a disk with a bigger one/remove one I can use a single "pvmove /dev/hdb" to move data around and get it done without tons of repartition and fs moves.
Yes, but I found it to be confusing when I went to install 10.2
Besides all the other lvm doc on google it's a presentation of lvm at http://www.techwiz.ca/~peters/presentations/lvm/ . It's a little old in that it was done before online resizing of ext3 was available but it tries to explain the basics of filesystems and lvm and that is still valid. The .sxi has a few notes added also so enable "notes" view. Yes, like everything it's confusing until you understand it. In simple terms you can say that you collect all available disk space you have ("LVM" above), concatenate them back to back and call that "vg01". #put a lvm signature on the partitions pvcreate /dev/sda8 /dev/sdb1 #create a new volume group vgcreate vg01 /dev/sda8 /dev/sdb1 After that you can almost treat that as one big disk but instead of using fdisk/cfdisk/yast partitioner/sfdisk to create partitions you use "lvcreate" (or yast partitioner) . lvcreate --size 10G --name datalv vg01 # creates 10G /dev/vg01/datalv mkfs /dev/vg01/datalv mount /dev/vg01/datalv /data As you see it's not that different from plain disk partitions. What happens under the hood is that if the first disk only have 2G free it will allocate the rest from the second disk and this without you even knowing about it. If you run out of space on /data you can then lvextend --size +10G /dev/vg01/datalv resize2fs /dev/vg01/datalv And move on with life with a 20G /data If you completely run out of diskspace and decide to add another disk pvcreate /dev/sdc1 vgextend vg01 /dev/sdc1 And then the new disk is added to the pool of free space.
One thing is that since /boot and /boot/grub/menu.lst is common for all installs you need to manually manage that area. I found that each os version have there own version numbering like vmlinuz-2.6.18.8-0.5-default/initrd-2.6.18.8-0.5-default so there is no conflict but they normally replace /boot/grub/menu.lst so I make sure I have a copy of menu.lst somewhere and then I manually merge the old and new menu.lst after each install.
That sounds like a smart idea. Would have saved me some heartache after I installed 10.2
Let me tell you what happened to me. After the 10.2 install both of the OS's were working fine. When I upgraded the kernel in 10.2 with Yast it replaced the old kernel and broke 10.0.
One last question; how big do you normally make the regular partitions andthe volumes? And I assume you do not leave any unused space, and must you assign it all? At home I have a mixed environment with a central nfs server where I store most of my stuff but when I build systems what I go with is
/boot, 100Mb, hd partition only created when I have raid1 or multiboot. If I just install one os I don't create /boot at all. / 10G, hd partition I wan't it to be big enough to hold base os including /usr but not /var. I don't really want the whole /usr but /usr/bin, /usr/sbin & /usr/lib are good to have when you need to recover from problems. If / fills up parts (like /usr/share) or the whole of /usr can be moved to lvm. LVM, Rest of disk /tmp, 1/2 ram(default), ramdisk (tmpfs) /var, 2G, LVM The size depends a lot on what I'm going to use the system for, but I want it away from / since it contains swap, =Phys ram, LVM This can as well a flat file and the size depends on total ram and you have lots of schools for the formula. 2xRAM was good when you had 4Mb but today you migth have 64G in a system and then you would almost never use swap and definitly not several G of swap. I put =Phys ram since I use ram/swap for /tmp and my systems are between 512Mb and 6G. /home, /data, /... All on lvm but the size depends on system usage. "must assign all", I do assign all hard disk space to something but I do not use up all my lvm space directly. That way I can expand the partition I made to small later without first shrinking something (shrinking is possible but it is a pain to do).
Bob S.
/ps -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Friday 2007-09-14 at 00:06 -0400, Peter Sjoberg wrote:
It must be a mess. And how about naming volumes, they all have to be unique no? So what does /etc or /var or whatever become when you install. Or do you just make disk1p5 and disk1p6 large enough to hold everything? And what about ubuntuor fedora or whatever. They all have /home, /var, etc. etc. If you think about it, it's not that much different then when using plain partitions. When you have one disk you are forced to call every partition sda1, sda2 and so on up to sda15. If you now install 4 different os versions, how do you keep track of what partition that is /var for each os?
You can label plain partitions, and use the label for mounting instead of the device name. In fstab: LABEL=320_home1 /home xfs noatime,nodiratime 1 2 LABEL=320_home2 /home2 reiserfs noatime,nodiratime,user,acl,user_xattr 1 2 - -- Cheers, Carlos E. R. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFG6nNmtTMYHG2NR9URAmweAJ46avwknm3p5wXnbFmPvx9VuBfVzwCfRlfg OKssqjtlW+vdZ/2eNg3GcTc= =KwwS -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Friday 14 September 2007 07:41, Carlos E. R. wrote:
The Friday 2007-09-14 at 00:06 -0400, Peter Sjoberg wrote:
It must be a mess. And how about naming volumes, they all have to be unique no? So what does /etc or /var or whatever become when you install. Or do you just make disk1p5 and disk1p6 large enough to hold everything? And what about ubuntuor fedora or whatever. They all have /home, /var, etc. etc.
If you think about it, it's not that much different then when using plain partitions. When you have one disk you are forced to call every partition sda1, sda2 and so on up to sda15. If you now install 4 different os versions, how do you keep track of what partition that is /var for each os?
You can label plain partitions, and use the label for mounting instead of the device name. In fstab:
LABEL=320_home1 /home xfs noatime,nodiratime 1 2 LABEL=320_home2 /home2 reiserfs noatime,nodiratime,user,acl,user_xattr 1 2
-- Cheers, Carlos E. R.
OK Peter & Carlos. We shall see. Bob S -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On 2007/09/14 21:44 (GMT-0400) Bob S apparently typed:
On Friday 14 September 2007 07:41, Carlos E. R. wrote:
You can label plain partitions, and use the label for mounting instead of the device name. In fstab:
LABEL=320_home1 /home xfs noatime,nodiratime 1 2 LABEL=320_home2 /home2 reiserfs noatime,nodiratime,user,acl,user_xattr 1 2
OK Peter & Carlos.
We shall see.
It's how my Factory system's fstab and grub are setup to boot. Partition labels are required in Fedora 7. -- "It yet remains a problem to be solved in human affairs, whether any free government can be permanent, where the public worship of God, and the support of religion, constitute no part of the policy or duty of the state in any assignable shape." Chief Justice Joseph Story Team OS/2 ** Reg. Linux User #211409 Felix Miata *** http://mrmazda.no-ip.com/ -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (4)
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Bob S
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Carlos E. R.
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Felix Miata
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Peter Sjoberg