Re: Move a SL6 server from md software raid 5 to hardware raid 5
(privately) There is another factor I did not mention called IPAHS, Innate
Perversity of Animate Homo Sapiens. We may be faced with that at this time.
{^_-}
On 2011/12/20 17:14, Jason Bronner wrote:
There is something to be said for minimizing downtime, but every time i've tried
getting tricky with something like that something else goes horribly wrong. i
believe IPIO was mentioned and Murphy probably has something else to say about
it, too.
Re: Move a SL6 server from md software raid 5 to hardware raid 5
There is something to be said for minimizing downtime, but every time i've tried getting tricky with something like that something else goes horribly wrong. i believe IPIO was mentioned and Murphy probably has something else to say about it, too.
Re: Move a SL6 server from md software raid 5 to hardware raid 5
Trying to rush this kind of procedure generally leads to much greater
downtime and lost data.
The technical name for those who take this risk without a backup is "foolish".
{o.o}
On 2011/12/20 06:22, Felip Moll wrote:
Thank you for your answers!.
Regarding to the backups I have an external backup system with bacula + tapes
and another with NFS, so it should not be a problem. The problem is that I want
to do all this process in a short period time to minimize the downtime.
Be sure that your e-mails will be useful to me. Thank you.
2011/12/20 Nico Kadel-Garcia mailto:nka...@gmail.com>>
On Tue, Dec 20, 2011 at 5:52 AM, Jason Bronner mailto:jason.bron...@gmail.com>> wrote:
> Felip.
>
> always always always: back up the array. create the new array. move the
old
> array to the new array. destroy the old array.
Amen. Also, in making the backup, consider using "star" if you use
SELinux. rsync and normal tar do not preserve SELinux attributes.
It is a good time to consider your backup policy. RAID is *not*
backup, and the white paper from Google at
http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/archive/disk_failures.pdf
Re: Move a SL6 server from md software raid 5 to hardware raid 5
Thank you for your answers!. Regarding to the backups I have an external backup system with bacula + tapes and another with NFS, so it should not be a problem. The problem is that I want to do all this process in a short period time to minimize the downtime. Be sure that your e-mails will be useful to me. Thank you. 2011/12/20 Nico Kadel-Garcia > On Tue, Dec 20, 2011 at 5:52 AM, Jason Bronner > wrote: > > Felip. > > > > always always always: back up the array. create the new array. move the > old > > array to the new array. destroy the old array. > > Amen. Also, in making the backup, consider using "star" if you use > SELinux. rsync and normal tar do not preserve SELinux attributes. > > It is a good time to consider your backup policy. RAID is *not* > backup, and the white paper from Google at > > http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/archive/disk_failures.pdf >
Re: Move a SL6 server from md software raid 5 to hardware raid 5
On Tue, Dec 20, 2011 at 5:52 AM, Jason Bronner wrote: > Felip. > > always always always: back up the array. create the new array. move the old > array to the new array. destroy the old array. Amen. Also, in making the backup, consider using "star" if you use SELinux. rsync and normal tar do not preserve SELinux attributes. It is a good time to consider your backup policy. RAID is *not* backup, and the white paper from Google at http://static.googleusercontent.com/external_content/untrusted_dlcp/research.google.com/en/us/archive/disk_failures.pdf
Re: Move a SL6 server from md software raid 5 to hardware raid 5
Felip. always always always: back up the array. create the new array. move the old array to the new array. destroy the old array.
Re: Move a SL6 server from md software raid 5 to hardware raid 5
Not as I see it. You take a backup to a large disk, or disks as the case
may be. That is your safety net. Then you try the md disks in the hard raid
controller. If they work, Bob's your uncle. If they do not work then create
the proper raid configuration on the hardware controller with the md disks
and copy in the backup. Perform the copying using a live CD to the extent
you can. At no time do you end up with twin RAID arrays. Of course, if you
have enough disks simply copy the md raid as an disk to the hard raid as a
disk. "tar" or "dd" imaging can work. If you use different disks in the
RAIDs then use tar or even cpio to copy the files rather than copy a pure
image. That will tend to optimize the partitioning to use the drive's
actual internal block size for creating partition boundaries.
{^_^}
On 2011/12/19 15:43, Felip Moll wrote:
Doing it this way seems to be a high risk operation.
Furthermore I want not do this because then I will have two raids: one raid per
software (md) into one per hardware.. my thoughts are about copying manually the
dirs of the operating system, then modifying configurations.. I think it is a
"more secure" process.
Thanks for the answer jdow ;)
2011/12/20 jdow mailto:j...@earthlink.net>>
First take a complete backup of the md raid.
Then if the laws if Innate Perversity of Inanimate Objects you'll be able to
move the disks and have them just work. Your data is protected. (If you had
no backup IPIO would, of course, lead to the transition failing
expensively.)
Even if IPIO does not work you restore from the complete backup to the same
disks they were on after the hardware RAID assembles itself. (Despite the
numerous times IPIO seems to work, I still figure it's a silly superstition.
It does lead to a correct degree of paranoia, though.)
{^_^}
On 2011/12/19 09:18, Felip Moll wrote:
Well, I will remake my question to not scare possible "answerers":
How to move a SL6.0 system with md raid (raid per software), to another
server
without mantaining the raid per software?
Thanks!
2011/12/16 Felip Moll mailto:lip...@gmail.com>
>>
Hello all!
Recently I installed and configured a Scientific Linux to run as a
high
performance computing cluster with 15 slave nodes and one master. I
did this
while an older system with RedHat 5.0 was running in order
to avoid users to stop their computations. All gone well. I migrated
node to
node and now I have a flawlessly cluster with SL6!.
Well, the fact is that while migrating I used the node1 to install
SL6 while
the node0 was hosting the old master operating system. Node1 has
less ram
and no raid capabilities, so I configured a Raid5 per software when
installing, using md linux software (which comes per default to a
normal
installation when you select "raid"). Node0 has a Raid 5 hardware
controller.
Now I want to move the new master node1, into node0. I thought about
this
and I have to shutdown node1, node0, and with a LiveCD partition the
harddisk of node0 and copy the contents of the disk of node1 into
it. Then
make grub install.
All right but, what do you think that I should take in consideration
regarding to Raid and md? I will have to modify /etc/fstab and also
delete
/etc/mdadm.conf to avoid md running. Anything more?
Thank you very much!
Re: Move a SL6 server from md software raid 5 to hardware raid 5
Doing it this way seems to be a high risk operation.
Furthermore I want not do this because then I will have two raids: one raid
per software (md) into one per hardware.. my thoughts are about copying
manually the dirs of the operating system, then modifying configurations..
I think it is a "more secure" process.
Thanks for the answer jdow ;)
2011/12/20 jdow
> First take a complete backup of the md raid.
>
> Then if the laws if Innate Perversity of Inanimate Objects you'll be able
> to
> move the disks and have them just work. Your data is protected. (If you had
> no backup IPIO would, of course, lead to the transition failing
> expensively.)
>
> Even if IPIO does not work you restore from the complete backup to the same
> disks they were on after the hardware RAID assembles itself. (Despite the
> numerous times IPIO seems to work, I still figure it's a silly
> superstition.
> It does lead to a correct degree of paranoia, though.)
>
> {^_^}
>
>
> On 2011/12/19 09:18, Felip Moll wrote:
>
>> Well, I will remake my question to not scare possible "answerers":
>>
>> How to move a SL6.0 system with md raid (raid per software), to another
>> server
>> without mantaining the raid per software?
>>
>> Thanks!
>>
>>
>>
>> 2011/12/16 Felip Moll mailto:lip...@gmail.com>>
>>
>>
>>Hello all!
>>
>>Recently I installed and configured a Scientific Linux to run as a high
>>performance computing cluster with 15 slave nodes and one master. I
>> did this
>>while an older system with RedHat 5.0 was running in order
>>to avoid users to stop their computations. All gone well. I migrated
>> node to
>>node and now I have a flawlessly cluster with SL6!.
>>
>>Well, the fact is that while migrating I used the node1 to install SL6
>> while
>>the node0 was hosting the old master operating system. Node1 has less
>> ram
>>and no raid capabilities, so I configured a Raid5 per software when
>>installing, using md linux software (which comes per default to a
>> normal
>>installation when you select "raid"). Node0 has a Raid 5 hardware
>> controller.
>>
>>Now I want to move the new master node1, into node0. I thought about
>> this
>>and I have to shutdown node1, node0, and with a LiveCD partition the
>>harddisk of node0 and copy the contents of the disk of node1 into it.
>> Then
>>make grub install.
>>
>>All right but, what do you think that I should take in consideration
>>regarding to Raid and md? I will have to modify /etc/fstab and also
>> delete
>>/etc/mdadm.conf to avoid md running. Anything more?
>>
>>Thank you very much!
>>
>>
>>
Re: Move a SL6 server from md software raid 5 to hardware raid 5
First take a complete backup of the md raid.
Then if the laws if Innate Perversity of Inanimate Objects you'll be able to
move the disks and have them just work. Your data is protected. (If you had
no backup IPIO would, of course, lead to the transition failing expensively.)
Even if IPIO does not work you restore from the complete backup to the same
disks they were on after the hardware RAID assembles itself. (Despite the
numerous times IPIO seems to work, I still figure it's a silly superstition.
It does lead to a correct degree of paranoia, though.)
{^_^}
On 2011/12/19 09:18, Felip Moll wrote:
Well, I will remake my question to not scare possible "answerers":
How to move a SL6.0 system with md raid (raid per software), to another server
without mantaining the raid per software?
Thanks!
2011/12/16 Felip Moll mailto:lip...@gmail.com>>
Hello all!
Recently I installed and configured a Scientific Linux to run as a high
performance computing cluster with 15 slave nodes and one master. I did this
while an older system with RedHat 5.0 was running in order
to avoid users to stop their computations. All gone well. I migrated node to
node and now I have a flawlessly cluster with SL6!.
Well, the fact is that while migrating I used the node1 to install SL6 while
the node0 was hosting the old master operating system. Node1 has less ram
and no raid capabilities, so I configured a Raid5 per software when
installing, using md linux software (which comes per default to a normal
installation when you select "raid"). Node0 has a Raid 5 hardware
controller.
Now I want to move the new master node1, into node0. I thought about this
and I have to shutdown node1, node0, and with a LiveCD partition the
harddisk of node0 and copy the contents of the disk of node1 into it. Then
make grub install.
All right but, what do you think that I should take in consideration
regarding to Raid and md? I will have to modify /etc/fstab and also delete
/etc/mdadm.conf to avoid md running. Anything more?
Thank you very much!
Re: Move a SL6 server from md software raid 5 to hardware raid 5
Well, I will remake my question to not scare possible "answerers": How to move a SL6.0 system with md raid (raid per software), to another server without mantaining the raid per software? Thanks! 2011/12/16 Felip Moll > Hello all! > > Recently I installed and configured a Scientific Linux to run as a high > performance computing cluster with 15 slave nodes and one master. I did > this while an older system with RedHat 5.0 was running in order > to avoid users to stop their computations. All gone well. I migrated node > to node and now I have a flawlessly cluster with SL6!. > > Well, the fact is that while migrating I used the node1 to install SL6 > while the node0 was hosting the old master operating system. Node1 has less > ram and no raid capabilities, so I configured a Raid5 per software when > installing, using md linux software (which comes per default to a normal > installation when you select "raid"). Node0 has a Raid 5 hardware > controller. > > Now I want to move the new master node1, into node0. I thought about this > and I have to shutdown node1, node0, and with a LiveCD partition the > harddisk of node0 and copy the contents of the disk of node1 into it. Then > make grub install. > > All right but, what do you think that I should take in consideration > regarding to Raid and md? I will have to modify /etc/fstab and also delete > /etc/mdadm.conf to avoid md running. Anything more? > > Thank you very much! > >
Move a SL6 server from md software raid 5 to hardware raid 5
Hello all! Recently I installed and configured a Scientific Linux to run as a high performance computing cluster with 15 slave nodes and one master. I did this while an older system with RedHat 5.0 was running in order to avoid users to stop their computations. All gone well. I migrated node to node and now I have a flawlessly cluster with SL6!. Well, the fact is that while migrating I used the node1 to install SL6 while the node0 was hosting the old master operating system. Node1 has less ram and no raid capabilities, so I configured a Raid5 per software when installing, using md linux software (which comes per default to a normal installation when you select "raid"). Node0 has a Raid 5 hardware controller. Now I want to move the new master node1, into node0. I thought about this and I have to shutdown node1, node0, and with a LiveCD partition the harddisk of node0 and copy the contents of the disk of node1 into it. Then make grub install. All right but, what do you think that I should take in consideration regarding to Raid and md? I will have to modify /etc/fstab and also delete /etc/mdadm.conf to avoid md running. Anything more? Thank you very much!
