[CentOS] Booting back into CentOS-6

Fri May 29 13:58:41 UTC 2015
philburt stortsky <philburtstortsky at writeme.com>

This, IMHO, is one of the more annoying bugs with the newer GRUB (which i assume is the bootloader you are using).  Specifically the newer grub can't, won't boot from a drive other than the one grub is on.  suggest you revert to grub 0.97 or, if any boot loader is or can be put on the drive with the 6.5 distro you can make that drive the boot drive in the bios, which is how i do it.  i.e. i just put grub on any drive i might want to boot from and install etc. with the drive i want to be able to boot to set as the boot drive in the bios.  of course, depending on how you are mounting drives this may break links etc. since the bios will have different names for the drives due to the different order of the boot media list in the bios.  hope that helps, it is highly annoying.

"We kill when we close our eyes to poverty, affliction or infamy. We kill when, because it is easier, we countenance or pretend to approve of atrophied social, political, educational and religious institutions instead of resolutely combating them."
- Hesse

> Message: 13
> Date: Fri, 29 May 2015 02:23:44 +0100
> From: Timothy Murphy <gayleard at eircom.net>
> To: centos at centos.org
> Subject: [CentOS] Booting back into CentOS-6
> Message-ID: <mk8f30$lf1$1 at ger.gmane.org>
> Content-Type: text/plain; charset="ISO-8859-1"
> 
> I'm currently running CentOS-7,
> but I'd like to re-boot into CentOS-6.5
> which I have on another partition.
> Although this OS is in the grub list when I boot,
> if I try to run it I get a segfault.
> I guess this is something to do with the change from grub to grub2?
> 
> In any case, I'm wondering if there is any simple way
> of booting into both CentOS-6 and CentOS-7?
> 
> -- 
> Timothy Murphy  
> gayleard /at/ eircom.net
> School of Mathematics, Trinity College, Dublin
> 
> 
> 
> 
> ------------------------------
> 
> Message: 14
> Date: Fri, 29 May 2015 02:52:53 +0100
> From: Timothy Murphy <gayleard at eircom.net>
> To: centos at centos.org
> Subject: [CentOS] Using Mariadb databases from old server
> Message-ID: <mk8gpm$ea1$1 at ger.gmane.org>
> Content-Type: text/plain; charset="ISO-8859-1"
> 
> I'm running CentOS-7, but I left some MySQL databases
> on my old CentOS-6.5 partition which I'd like to retrieve. 
> I assume they are contained in the file /var/lib/mysql/ibdata1 ?
> 
> Could I just copy this file to /var/lib/mysql in CentOS-7?
> Or is there some way Mariadb or phpMyAdmin can import mysql databases
> from a server that is no longer running?
> 
> -- 
> Timothy Murphy  
> gayleard /at/ eircom.net
> School of Mathematics, Trinity College, Dublin
> 
> 
> 
> 
> ------------------------------
> 
> Message: 15
> Date: Thu, 28 May 2015 19:55:41 -0700
> From: Gordon Messmer <gordon.messmer at gmail.com>
> To: CentOS mailing list <centos at centos.org>
> Subject: Re: [CentOS] New controller card issues
> Message-ID: <5567D52D.5060108 at gmail.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
> 
> On 05/28/2015 03:02 PM, Valeri Galtsev wrote:
> >
> > If I get you correctly you are saying that 3ware RAID cards are prone to
> > hardware failures - as opposed to software RAID which is not (as it does
> > not include hardware, so never has a hardware failures), right? No this is
> > a joke of course. But it's the one one asked for ;-)
> 
> Software RAID uses whatever controller the disks are connected to. 
> Often, that's the AHCI controller on the motherboard.  And those 
> controllers are almost always more reliable than 3ware.  Seriously.  No 
> joke.
> 
> > Again, I don't know your statistics: i.e. how many did you use,
> 
> Hundreds of systems, both with 3ware and with software RAID.
> 
> > how many
> > of them died (failed as hardware).
> 
> Not many, but some.  A handful of data corruption cases (maybe 5?  I 
> don't have logs).  One BBU failure that resulted in a system that 
> wouldn't boot until it was removed (and a couple of hours down time 
> while 3ware techs worked that ticket).  A couple of times when we really 
> wanted to move an array of disks and couldn't.
> 
> Vs zero reliability issues with software RAID.
> 
> > How well surge-free the power is.
> 
> We always used trusted UPS hardware.
> 
> > How
> > well the guys who installed your cards into your boxes followed static
> > discharge precautions
> 
> Our systems were built by a professional VAR.  Employees always wore 
> ground straps.  There were other anti-static measures in place as well. 
>   I had been to the facility.
> 
> And I'll throw you a curveball:
> 
> I've argued that software RAID is more reliable than 3ware cards, 
> specifically.  In the world of ZFS and btrfs, you absolutely should not 
> use hardware RAID.  As you mentioned earlier, hardware RAID volumes 
> should scan disks regularly.  However, scanning only tells you if disks 
> have bad sectors.  It can also detect data (parity) errors, but it can't 
> repair them.  Hardware RAID cards don't have information that can tell 
> them which sectors are correct.  ZFS and btrfs, on the other hand, 
> checksum their data and metadata.  They can tell which sectors are 
> damaged in the case of corruption such as bit flips, and which sector 
> should be used to repair the data.
> 
> Now, btrfs and ZFS are completely different from software RAID.  I'm not 
> comparing the two.  But hardware RAID simply has too many deficiencies 
> to justify its continued use.  It should go away.
> 
> 
> ------------------------------
> 
> Message: 16
> Date: Thu, 28 May 2015 21:22:45 -0700
> From: Keith Keller <kkeller at wombat.san-francisco.ca.us>
> To: centos at centos.org
> Subject: Re: [CentOS] New controller card issues
> Message-ID: <l56l3cxekb.ln2 at goaway.wombat.san-francisco.ca.us>
> Content-Type: text/plain; charset=us-ascii
> 
> On 2015-05-28, Valeri Galtsev <galtsev at kicp.uchicago.edu> wrote:
> >
> > I do use both LSI and 3ware.
> 
> Both are now owned by Avago.  (Not sure when that happened, last I
> looked LSI was its own company.)
> 
> > For me big advantage of 3ware is transparent
> > interface. By which I mean web interface. There is command line interface
> > for both and 3ware command line interface may be less confusing for me.
> 
> I find the 3ware CLI a little clunky but easy to understand.  I find the
> LSI CLIs (both MegaCLI and storcli) incredibly confusing, and the GUI
> interface is not intuitive (and I think doesn't expose all the
> information about the controller; the Nagios LSI plugin found errors
> that I could find no trace of in the GUI).
> 
> > Sorry for long comment. I did feel 3ware deserves more respect than one
> > might draw from this thread otherwise.
> 
> Agreed; I'll share some of my experiences in another post.
> 
> --keith
> 
> -- 
> kkeller at wombat.san-francisco.ca.us
> 
> 
> 
> 
> ------------------------------
> 
> Message: 17
> Date: Thu, 28 May 2015 21:36:31 -0700
> From: Keith Keller <kkeller at wombat.san-francisco.ca.us>
> To: centos at centos.org
> Subject: Re: [CentOS] New controller card issues
> Message-ID: <fv6l3cx8ub.ln2 at goaway.wombat.san-francisco.ca.us>
> Content-Type: text/plain; charset=us-ascii
> 
> On 2015-05-28, Valeri Galtsev <galtsev at kicp.uchicago.edu> wrote:
> >
> > Now, seriously: of more than a couple of dozens of cards I used during
> > last about 13 years not a single one died on me.
> 
> I have had a couple dozen hardware RAID controllers over the years.  I
> have not had the success you've had, but I've had very few hard
> failures.  I have had one data loss event, where a bad BBU was causing
> problems with an old controller (of course I had backups, as should
> everyone).  I've had two other controllers just die, but replacing it
> was easy, and the new controller recognized the arrays immediately.
> This includes moving two different disk arrays from two different 9650s
> to two different 9750s, so whoever wrote that arrays are not compatible
> across different models is at least partly incorrect.
> 
> I do also have an LSI controller, which has been fine, but it's only one
> controller so it's not enough data points to draw any conclusions.  I also
> have an md RAID array (on a very old 3ware controller which doesn't
> support RAID6), and it's also been fine.  It hasn't suffered through any
> major catastrophes, though I do think it's had one or two fatal kernel
> panics, and once or twice had a hard reset done.  It's still fine even
> with a small number of really crappy "green" drives still in the array
> (I learned that lesson the hard way--don't use green drives with a hardware
> RAID controller!).
> 
> --keith
> 
> -- 
> kkeller at wombat.san-francisco.ca.us
> 
> 
> 
> 
> ------------------------------
> 
> Message: 18
> Date: Fri, 29 May 2015 08:32:47 +0300
> From: Todor Petkov <zakk at online.bg>
> To: CentOS mailing list <centos at centos.org>
> Cc: Timothy Murphy <gayleard at eircom.net>
> Subject: Re: [CentOS] Using Mariadb databases from old server
> Message-ID: <62128b8c308448402a65c2b760d4d88c at online.bg>
> Content-Type: text/plain; charset=US-ASCII; format=flowed
> 
> On 29/05/2015 04:52 AM, Timothy Murphy wrote:
> > I'm running CentOS-7, but I left some MySQL databases
> > on my old CentOS-6.5 partition which I'd like to retrieve.
> > I assume they are contained in the file /var/lib/mysql/ibdata1 ?
> > 
> > Could I just copy this file to /var/lib/mysql in CentOS-7?
> > Or is there some way Mariadb or phpMyAdmin can import mysql databases
> > from a server that is no longer running?
> 
> The C6 partition is part of the new server, so you are able to mount it 
> and copy files from it, is this correct? Have you done something with 
> the MariaDB or it's still clean installation?
> 
> 
> 
> ------------------------------
> 
> Message: 19
> Date: Fri, 29 May 2015 09:45:24 +0200
> From: G?tz Reinicke - IT Koordinator 	<goetz.reinicke at filmakademie.de>
> To: CentOS <centos at centos.org>
> Subject: [CentOS] NSS Tools certutil buggy ? Centos 6 nss-tools-3.18.0
> Message-ID: <55681914.1040504 at filmakademie.de>
> Content-Type: text/plain; charset="utf-8"
> 
> Hi,
> 
> I try to add a certificate to a fresh certificate db, but the trust
> attributes are not set as expected. Neither can I change tham.
> 
> The cert/pem is valid and double checked :)
> 
> 
> 	Any idea/suggestion?
> 
> 
> certutil -N -d certdb-test
> 
> certutil -A -n "foobar" -t "u,u,u" -d certdb-test/ -i foobar.pem
> 
> certutil -L -d certdb-test/
> 
> 
> Certificate Nickname                            Trust Attributes
>                                                 SSL,S/MIME,JAR/XPI
> foobar                                         ,,
> 
> 
> 
> certutil -M -n "foobar" -t "u,u,u" -d /tmp/certdb-test/
> 
> 
> certutil -L -d certdb-test/
> 
> Certificate Nickname                            Trust Attributes
>                                                 SSL,S/MIME,JAR/XPI
> foobar                                         ,,
> 
> 
> 
> 
> 
> 	Thanks and regards . G?tz
> 
> -- 
> G?tz Reinicke
> IT-Koordinator
> 
> Tel. +49 7141 969 82 420
> E-Mail goetz.reinicke at filmakademie.de
> 
> Filmakademie Baden-W?rttemberg GmbH
> Akademiehof 10
> 71638 Ludwigsburg
> www.filmakademie.de
> 
> Eintragung Amtsgericht Stuttgart HRB 205016
> 
> Vorsitzender des Aufsichtsrats: J?rgen Walter MdL
> Staatssekret?r im Ministerium f?r Wissenschaft,
> Forschung und Kunst Baden-W?rttemberg
> 
> Gesch?ftsf?hrer: Prof. Thomas Schadt
> 
> 
> ------------------------------
> 
> Message: 20
> Date: Fri, 29 May 2015 12:00:07 +0100
> From: Timothy Murphy <gayleard at eircom.net>
> To: centos at centos.org
> Subject: Re: [CentOS] Using Mariadb databases from old server
> Message-ID: <mk9gro$pq3$1 at ger.gmane.org>
> Content-Type: text/plain; charset="ISO-8859-1"
> 
> Todor Petkov wrote:
> 
> >> I'm running CentOS-7, but I left some MySQL databases
> >> on my old CentOS-6.5 partition which I'd like to retrieve.
> >> I assume they are contained in the file /var/lib/mysql/ibdata1 ?
> >> 
> >> Could I just copy this file to /var/lib/mysql in CentOS-7?
> >> Or is there some way Mariadb or phpMyAdmin can import mysql databases
> >> from a server that is no longer running?
> > 
> > The C6 partition is part of the new server, so you are able to mount it
> > and copy files from it, is this correct? Have you done something with
> > the MariaDB or it's still clean installation?
> 
> I did add something to Mariadb on the new CentOS-7 system,
> but I don't mind deleting it and starting again.
> I can mount the partition with the old mysql files on it.
> Could I just copy the contents of /mnt/var/lib/mysql
> to the new system?
> There are files with the same name, eg ibdata1, on both systems.
> Could I have an ibdata2 ?
> 
> Any suggestions gratefully received.
> 
> -- 
> Timothy Murphy  
> gayleard /at/ eircom.net
> School of Mathematics, Trinity College, Dublin
> 
> 
> 
> 
> ------------------------------
> 
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> 
> End of CentOS Digest, Vol 124, Issue 29
> ***************************************
>