I will do a completely new setup of my system and need to have a few questions answered.
The setup will be /boot and then LVM encrypted. HOWEVER, I need space to be partitioned for another OS.
Now my questions: the install guide about LVM is not very clear when it comes to sizing and to the position of the partition.
If you run the expert dialog during installation, any free hard disk space is also listed and automatically selected. To provide more disk space to openSUSE®, free the needed space starting from the bottom toward the top of the list (starting from the last partition of a hard disk toward the first). For example, if you have three partitions, you cannot use the second exclusively for openSUSE and retain the third and first for other operating systems.
All cases are described in which openSUSE is the second OS to be installed. This is not my case. I wish opensSUSE to be installed as the first OS and to maintain available space to install and may change from time to time another OS or in which to experiment maybe the Factory version, just to do an example.
when the installer makes the proposal of the LVM it attributes the entire disk. How can I avoid this? IF I did well understand the guide, openSUSE must be together with /boot on the last
partitions of the disk? So do I have to define another partition and format it with whatever, in order to have the installer taking the rest and simply performing the standard setup proposal? - if I leave this space not formatted (or formatted) and at a time I install the new OS, will Grub in /boot still be available (we speak e.g. of another Linux distribution or of a beta of openSUSE) after the installation of another OS into this partition? If not, how could I reactivate it?
where should I install the bootloader when installing with this intention (please motivate your advice and be explicit about the consequences of this choice, my understanding is currently that it is better to avoid MBR and to use /boot. Is this correct? The root partition is encrypted and therefore not applicable AFAIK. Again all this is with the thought of having a kind of playground allowing for the installation of one supplemental OS for testing / didactic purposes without virtualizing the thing. Virtualization made me not really happy, KVM is quite complicated to setup and virtualbox is also no option to me. So I am looking for a hardware solution.
is this feasible at all or maybe this is not possible any more or never was in this configuration? Maybe it is known to cause too many problems?
Can I use trusted grub instead of Grub2 at install time? (Grub2 I do not see it to give me any advantage if I am using no UEFI bios). I am asking that because when I tried to install grub in substitution of grub2, in the old configuration I had, it failed and although yast indicated grub legacy installed, grub 2 continued to be present, could not be uninstalled and continued to be the default bootloader (one of the reasons why I try the new install - together with the space problem). Symptoms where that when installing it stopped at 100% of install and blocked yast.
Size of swap. I do not understand what is the right amount of swap. The system has 8GB of RAM. Now people say that 2 GB is enough and the automated proposal is such. But if I would be running a virtual machine or a bigger monolitical app (like STATA or similar) and the system - a laptop - goes "suspend to RAM and after a while suspend to disk, would the size of swap not have to be identical to the size of RAM to avoid surprises? So I would need to define a swap of 8GB?
Do not accept this proposal and create partitions/crypto/LVM manually
(Grub2 I do not see it to give me any advantage if I am using no UEFI bios).
Actually the main advantage of grub2 is when you do not have EFI. EFI makes booting quite simple.
would the size of swap not have to be identical to the size of RAM to avoid surprises? So I would need to define a swap of 8GB?
If you want to be absolutely sure under any conditions you will need separate suspend partition (vollume) equal to RAM. swap may not have free space at the time you want to suspend.
Which advantages would I have with Grub2? I am running a machine with TMP module. with all the precedent editions that did work fine with trusted grub. I was astonished that Grub2 could not be substituted and ask myself if this is a technical issue or a damage that the original system had with the bootloader. Does Grub2 make any use of the TPM module? If I set a password in Grub2 is this setting “safe” and equivalent to trusted grub? The question is there because, when you choose grub2 (after having had grub legacy selected) there is still a warning message that Grub2 is “beta”. So I am confused, I thought this is not the case anymore.
Creating crypto/LVM:
Physical Extend Size. This value defines the size of a physical block in the volume group
. What are the consequences of this choice? How big / small should a physical block be?
Creating encrypted LVM by hand:
Let me see if I get this right.
I create the PVs corresponding to the size I want to attribute.
I do not format but put “filesystem ID 0x8E Linux LVM”
Then I have to create the VG (volume group) system.
Choose “physical extend size”
Once done this I attribute the PVs to the VG. *Do I have to encrypt now or at step3? *
And then I define the LVs (that is I tell the OS what will be used for what: /root /swap /home).
So mainly I do am still confused what physical block size is best to be used and when the encryption step comes in.
Thank you.
It does not depend on knowing BIOS disk order. Which is something you generally have no way to find out as soon as you have more than one disk.
Does Grub2 make any use of the TPM module?
Not that I know of.
when you choose grub2 (after having had grub legacy selected) there is still a warning message that Grub2 is “beta”.
grub2 was released shortly before openSUSE 12.2 was released so I guess nobody had time to remove it. Also release status of software and release status of integration of this software into distribution does not necessarily coincide. I think there is bug report about it, you may check current status.
Creating crypto/LVM: . What are the consequences of this choice? How big / small should a physical block be?
I do not know. It is up to you. I usually follow rule - if I do not know answer, use default.
Well, this is the difficulty. I found various indications on the web. Apparently for the LVM standard it was important at the beginning because the default was 4M and that would give you PVs to a max of 256GB. But then I found threads claiming that this was outdated and that LVM2 substantially had 32M as default and had no problems even if lower sizes where chosen because LVM2 had no restrictions on the maximum number of physical extensions (or at least supports a very high number). If I well understand it would be more important for extending after the creation the LVM, which would not be applicable because if you use the encrypted LVM it is no more possible to alter sizes.
In short: a lot of contradictory info on the net and not many clear indications of the importance and the best size for a laptop or PC. More questions on 11-100TB discs with LVM for servers…