forget upgrade, what to save and blend with new install
Ralph Shumaker
rafazap at cwnet.com
Sat Nov 5 11:26:42 PST 2005
Excellent detail! And you mentioned a few things that I never would
have thought of on my own. Thank you for taking the time to type it up.
I do have a few questions though:
DJA wrote:
> Ralph Shumaker wrote:
>
>> Ever since I've upgraded my friend's pc (from rh9 to fc3), the pc has
>> been experiencing wierd problems. I would like to chuck it all,
>> except for the stuff I should keep.
>>
>> I figure I should keep /home, but what else?
>>
>> Now, just for the sake of argument, let's say that I'm keeping only
>> "/home" and "/stuff". Should I first wipe the drive, do the fresh
>> install, and *then* dump /home and /stuff back in? Or should I dump
>> them back in *before* doing the fresh install.
>
>
> Here are a few helpful things (in no particular order) I've learned
> over the years about upgrading/reinstalling Redhat and Fedora Core on
> home systems.
>
> 1) Re-installing works out better than upgrading. I format all
> partitions except /home and occasionally /usr/local. I also
> backup /etc (home file servers with gobs of disk space are
> wonderful!).
Yeah, I used the new HDD that I bought for my system (but not yet
installed) and did "dd if=/dev/hda of=/dev/hdg". Then, after verifying
as best I could, I wiped hda, installed, and copied /home back on top of
it. The old installation was chopped up into various partitions. But I
dispensed with that (for the most part) and threw everything into one
partition (except for swap obviously). The way I had chopped it up
before left too much space in the wrong places. (I will reply (below)
to your comment about LVM.)
> 2) There is little point in preserving existing apps. At least the more
> pedestrian ones. By the time you upgrade to a newer version of the
> OS, most if not all of those apps are likely more out of date the the
> OS itself. Plus often enough, you'll find the latest versions some
> apps don't play well with older incarnations of the kernel or some
> library or six. Fedora Core (FC) comes with a decent enough selection
> of apps that you don't really need to keep cruft around. Which brings
> up the next point.
"the more pedestrian ones"? What does that mean?
> 3) Each successive version of FC has included fewer and fewer apps in
> the standard distribution, so as to fit the entire distro on only
> four CD's (I'm guessing so as to keep the burning and mailing costs
> down for repackagers).
Yeah, I wish they would include these on CDs, maybe called "Optional
Extras".
> 4) *DO NOT* create any user accounts from within the FC installer unless
> you don't mind UID/GID pairs based on some goof ball Redhat lunacy
> (IMHO). This is especially true if you are preserving /home and any
> apps owned by non-system, non-root users.
>
> Any user you create from within the installer (and also with
> System-config-user) will create a UID of n and a GID of n+1, starting
> with UID=501. So the UID/GID list will start 501/502, 503/504,
> 505/506, etc. Maybe there is some esoteric or security reason for
> this, but I like my UID/GID pairs to match e.g. 506/506.
>
> If you create users from within the installer (i.e. using the GUI),
> you are given no control over either UID/GID or home directory
> locations or names. It's a PITA to fix this after the installation,
> especially if the user has already logged in, and even worse if that
> user has run X. In fact, you have to be careful in creating users
> in System-config-users also, because its defaults make the same mess.
>
> Use the CLI tool to create the users and groups, and then the GUI
> tool to maintain them if you like. If you use the GUI tool to create
> new users, make sure you create their group first or you might not
> get what you want, and the GUI tool won't let you remove or rename a
> group unless you first remove its users. Also the GUI tool doesn't
> handle passwords as flexibly.
I created them from the graphical interface (not during the install,
except for maybe the user that was 501 on the old installation). Before
creating *any* of the users on the new install, I noted from the old
install all the user and group info from the users and groups gui. I
had no trouble creating the same sets on the new install. I did not
create groups. It automatically created the groups (correctly) when I
created the users. But, maybe this process was helped by my having
copied /home before doing this. Actually, I do not recall when I copied
/home, whether before or after. I knew each user's password, so I don't
remember if I entered this information when setting up the users or if
it didn't even ask me.
> 5) Password and Shadow files seem to migrate just fine. Keep a copy of
> the more complex configuration files, including but not limited
> to, fstab, smb.conf, hosts, or any other fancy shit you hand-tweaked.
> These are handy for reference if nothing else.
Not knowing what to keep, I temporarily used my new HDD (which was
supposed to be replacing my other HDD but delayed by this) and kept it
all. But all I copied back in (so far) is /home .
> 6) A re-install is a perfect time to do some repartitioning. I prefer
> to switch to the console and run Fdisk for that rather than
> Disk Druid, although I prefer Disk Druid for establishing mount
> points. I also prefer Disk Druid for setting up Logical Volumes -
> which I recommend BTW. I put everything into an LV except /, and
> /boot (drat that italicizing notation!).
How does one invoke Disk Druid outside of the install process?
Are you saying that you even put swap into an LV?
I've never done anything with LVs. Are they easy for the non-initiated?
And what is the reasoning behind partitioning, anyway? Either I never
understood this, or I have just plain forgotten.
> 7) *BACK UP EACH USER'S MOZILLA AND/OR FIREFOX DIRECTORIES AND FILES*.
> While FC still includes Mozilla, Firefox and Thunderbird are now the
> default browser and email apps, respectively. And they don't
> completely migrate existing folders and files from your existing
> older Mozilla or Netscape configuration.
I took care of this by selecting Mozilla in the install list. It was
not selected by default, but it was there (fc3).
> You very likely will find some or all of the mail folders missing
> for each user in Thunderbird (TB). The data is still intact, but has
> to be manually copied from the old .<email_client_folder> to TB. Make
> sure you look at /all/ your existing folders (e.g. Sent, Saved,
> In Box, etc.) before you use that account in TB or you'll play hell
> trying to merge stuff back in later. I recommend you compress all
> existing mail folders before the migration.
>
> Firefox doesn't seem to import Tab Sets reliably from Mozilla.
> So you'll have to recreate those again from scratch. I didn't have
> any problems with bookmarks.
Is there any advantage to using TB and FF over mozilla?
> 8) Do a 'yum -y update' immediately after the initial install. This will
> actually take significantly longer with FC1-FC3 than the install. FC4
> is not so bad as there haven't been as many updates, and the default
> app list is much smaller.
>
> Don't forget to change the Yum default repository lists to faster
> sites. Also, Fedora (Yum?) has changed where it looks for the list
> repositories:
>
> [dallen at proteus miscellaneous]$ ls -la /etc/yum.repos.d/
> total 56
> -rw-r--r-- ... 233 Nov 1 2004 fedora-devel.repo
> -rw-r--r-- ... 931 May 24 22:21 fedora.repo
> -rw-r--r-- ... 280 Nov 1 2004 fedora-updates.repo
> -rw-r--r-- ... 282 Nov 1 2004 fedora-updates-testing.repo
>
> These are now pointed to by /etc/yum.conf.
How do I change them to "faster sites"? How do I know what is "faster"?
> 9) Redhat (Fedora) no longer includes any software which is encumbered
> (i.e. is not OSF compatible), including most multimedia stuff, so
> you'll have to get that from its maintainers. Freshrpms used to
> include a lot of those apps, but the list has shortened
> considerably.
>
> 10) I've found that with disk space being so cheap now that it's less
> hassle for me to just do a full install (i.e. Install Everything)
> rather than cherry pick which stuff I want and don't want.
>
> I did do a "Server Configuration" on my file server, but that was
> the exception. Installing everything seems to lessen my having to
> chase around for the odd missing library or other dependency when
> adding some new app on a desktop box.
>
> Of course doing a full install means you /will/ have to turn off more
> unneeded services afterwards (why does Redhat think that just because
> I installed Canna, I need it running?). Naturally, laptops are an
> obvious exception to my own rule (unless, of course like me, your
> laptop came with 100 GB hard drive. :-D
>
> 11) If you are moving from RH9 and older, then I see little reason to go
> with anything less than Fedora Core 4 (FC4). If you are overly
> cautious, FC3 will do, but FC4 seems more than stable enough for me,
> and I expect FC5 won't be far off now. FC4 also seems to handle
> things like USB storage and wireless better.
FC4 did not work on my PC for some reason. IIRC, the install went
smoothly but first boot would freeze. What I do remember vividly is
that the freeze was consistent. The same place, the same info, the same
everything, every time.
> 12) If you cant' find your CD/DVD drive, look in /etc/media. This is
> where FC now mounts removable media. Autodetecting of these devices
> (USB Flash drives, etc.) works nicely in FC4. There's not even any
> need to create a mount directory anymore as it's now done on the fly
> once the drive is detected, and it's removed once the drive is
> unmounted.
>
> Redhat-config-<service_name> has been changed to
> system-config-<service_name>.
>
> There are a few other changes of directory names and file
> relocations. Redhat seems to like to do that with nearly every new
> version. But then I /like/ adventure.
>
> 13) If you've got an AMD64, don't forget to get the 64-bit ISO's rather
> than the x86 ISO's. I have heard that some games don't play nice in
> the 64-bit FC4 - NeverWinter Nights being one example - so I've
> stuck with the x86 version for now.
>
> 14) SCSI support seems to get worse and worse on my Tyan K7 Thunder
> mobo with each new kernel. I've filed a couple of Bugzilla reports
> with Fedora but have yet to receive any solutions. But I think that
> is a kernel issue rather than a distro problem. Or at least I like
> to think so. It's probably not relevant here as regards Fedora Core,
> but it's been a nagging problem since kernel 2.6.12.
>
> Others may have tips or workarounds which contradict what I've
> mentioned here. And I may have forgotten something which will either
> hand you a shovel or a ladder. I'm by no means an admin type, and no
> doubt there are all kinds of clever little tricks to squashing each of
> the items above. This is just info based on what works, or not, for me
> such that I now have a mostly workable and less painful job when it
> comes time to update my Fedora boxen.
>
> So, if none of this helps - tough!
>
>
Thanks again for going into such detail.
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