On 3/7/2010 12:33 AM, Michael Evans wrote:
On Sat, Mar 6, 2010 at 11:03 PM, Timothy D. Lenz<tlenz@xxxxxxxxxx> wrote:
On 3/5/2010 11:43 PM, Michael Evans wrote:
On Fri, Mar 5, 2010 at 8:51 PM, Timothy D. Lenz<tlenz@xxxxxxxxxx> wrote:
On 3/5/2010 1:22 PM, Michael Evans wrote:
On Fri, Mar 5, 2010 at 11:00 AM, Timothy D. Lenz<tlenz@xxxxxxxxxx>
wrote:
Current setup, 3 500gb sata drives, each with 3 partitions.
The first partition of each drive make up raid1 md0 boot and most
software
The next partition of each drive make up raid1 md1 swap
The 3rd partition of each drive make up raid5 md2 main data storage
There is also a 40gb ide drive with 2 partitions, boot/software and
swap.
It
was used for install and setup. But I never got boot changed over to
md0.
So
currently md0 is not in use. md0 and md2 are mounted to folders on the
40gb
so a precopy to md0 could be made before booting with a cd and copying
what
ever is left that needs coping. and to use md2.
Current
# /etc/fstab: static file system information.
#
#<file system> <mount point> <type> <options>
<dump>
<pass>
proc /proc proc defaults 0 0
/dev/hda1 / ext3 defaults,errors=remount-ro 0
1
/dev/hda5 none swap sw 0 0
/dev/md0 /mnt/md0 ext3 defaults 0 0
/dev/md2 /mnt/md2 ext3 defaults 0 0
/dev/hdb /media/cdrom0 udf,iso9660 user,noauto 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto 0 0
I want to change md0 and md1 from 3 drive mirriors to 2 drive mirrors.
Finish changing over to booting from md0, move swap to md1 and move the
mount point for md2 to md0
Remove the the ide drive to free up space for the 4th 500gb drive.
Copy md2 over to the new 500gb temparally.
Get rid of the current md2 freeing up the 3rd drive since it was
already
taken out of the mirrors above.
Make a new md2 raid1 with the remaining space of the first 2 sata
drives.
Move the data from the 4th drive back to the new md2
Repartition the 3rd drive to 1 partition same as the 4th drive.
Make raid1 md3 from the 3rd and 4th drives.
It's the steps/commands to change md0 and md1 from 3 drive mirrors to 2
drive mirrors that I'm not sure about. Though now looking at fstab I
see
I
never even switched over the swap. So I guess, those to arrays would be
rebuilt. So it's more how to do that without messing with md2.
The computer is still on grub1. I haven't updated it it.
So you have:
[3-devices]
Raid 1: Unused
Raid 1: Unused
Raid 5: Used - 3 disks
[1-device]
Boot + swap
Just swapoff the raid-swap you want to re-create, then:
mdadm -S /dev/md(swap)
mdadm -S /dev/md(boot)
mdadm --zero-superblock /dev/devices in those arrays
Repartition those two areas of the disks as necessary.
Create new boot and swap partitions.
For boot make SURE you use either -e 0.90 OR -e 1.0 . Given the
nature of /boot I'd say use -e 0.90 on it.
For everything else, including swap use -e 1.1 and optionally
write-intent bitmaps.
At this point you should be able to move /boot and your swap off of
the 40gb drive; just remember to re-install grub and that your BIOS
likely sets the boot drive as bios-drive 0 regardless of which SDA/HDA
linux sees it as. This is what the device.map file is used to tell
grub.
I lost exactly what you wanted the result to look like amid a long
list of steps you /thought/ you needed to make to get there and
references to md numbers that only have meaning to you. However it
seems that you were mostly stuck getting to this point, so you might
be able to determine a plan using the data you've yet to share with
the rest of us with that 40gb drive out of the equation.
Remember that you can't reshape raid10 yet, but you can start raid10
with 'missing' devices (and add in the spares later).
can't make it much clearer, and I don't know where you got raid10 from.
ARRAY /dev/md0 level=raid1 num-devices=3
UUID=e4926be6:8d6f08e5:0ab6b006:621c4ec0
ARRAY /dev/md1 level=raid1 num-devices=3
UUID=eac96451:66efa3ab:0ab6b006:621c4ec0
ARRAY /dev/md2 level=raid5 num-devices=3
UUID=a7ed721e:04b10ab6:0ab6b006:621c4ec0
md 0 and 1 I want to change to 2 deivces.
Then get it booting from md0 which I think I know how to do as I got
another
computer working that way. Then I can dump the ide drive making room for
another 500gb sata. It will be used to store the data from md2 while md2
is
remade from a 3 device raid5 to a 2 device raid1. This frees up a drive
giving me 2 500gb drives to make another 2 device raid1. Its the
seperating
out 1 device from each of the current raid1's, md0 and md1 that I was
asking
about.
That was concise enough to be worth reading through to get your desired
result.
I already told you how to do the safe portion of your last operation.
Actually, I can see one benefit from two raid 1s over raid10; you
could stripe them using LVM and for very little extra cost have a lot
more flexibility.
After you've followed my last email to get the system booting off your
raid devices, you can replace the 40 with a 500, and then use the
/new/ 500 to start a raid 1 with one device set as 'missing'.
StartSlower but totally safe way:
However what I'd do if I were you is get everything I could off of the
40gb drive; it would only take 10 DVDs at worse case; presuming it
won't fit within ~500gb.
1) Duplicate all your data from the raid5 on to the single disk in a
raid 1 + missing configuration.
* you now have 1 copy with parity, and 1 copy waiting for mirroring.
(two copies and some parity)
2) Fail one of the partitions from the raid5, --zero superblock it.
* you now have 1 copy without parity, and 1 copy waiting for
mirroring, and one free drive. (two copies)
3) --add the previous parity partition as part of the mirror set; IT
MUST BE>= the size of the other partition in that mirror.
* You have 1 copy without parity, 1 full copy being mirrored in to two
copies.
4) WAIT for the mirroring operation to finish.
5) Optionally 'check' the mirror copy.
* You now have 1 copy without parity, 1 fully mirrored copy (3 copies
of your data)
6) With a fully safe copy of your data, and two partitions you can
start a wider range of procedures.
You could create two more raid 1 + missing arrays
setup LVM with striping across them
copy your data over in to one logical volume
++THEN AGAIN in to a second logical volume
(Manually creating two copies of your data; this won't protect against
drive failure but it will protect against individual failed sectors,
which may be good enough.)
Finally one at a time fail out members of the intact raid1 set and add
them to the new raid 1s.
Or probably proceed through other ideas; though none seems as
appealing to me as what I just wrote; 4 drives isn't enough to
seriously consider raid 5 or 6, and with the size of the drives you'd
really be better off with going for raid 6, which is much slower and
only slightly less risky than raid 1 + striping via LVM.
I don't need to combine the two large arrays. They are mostly for storing
recordings for vdr. With vdr, the storage folders are video0, video1,
video2,... and you provide the path to video0 with the others being in the
same parent folder. When it records, it sends the file to the folder with
the most free space and if that is not video0, then video0 gets a link to
where it really is.
I don't understand where "For boot make SURE you use either -e 0.90 OR -e
1.0 ." comes in. When I partitioned the drives, I set them all to type fd.
and made the first partition of each drive bootable. To create the arrays I
used:
sudo mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1
--spare-devices=1 /dev/sdc1
sudo mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2
--spare-devices=1 /dev/sdc2
And to format them:
sudo mkfs.ext3 /dev/md0
sudo mkswap /dev/md1
Latter I used grow to change from a spare to a 3 way mirror.
Please, reply to ALL or manually add the list back to the message.
You'll want the two types I specified for any boot device since it
then appears to be a normal partition that happens to have an exact
copy on another partition, except for a little bit at the end which is
where the raid metadata is.
For that same reason, using mdadm 1.1 or 1.2 would be preferable for
any devices which are not directly used for boot. Those place the
data at the beginning thus ensuring that any set of layering
(raid/lvm/filesystems) gets unpacked in the correct order since there
is no question how they are stacked.
Also, I don't really see how that changes the directions for getting
your smaller drive out of the system so that you can proceed. It
sounds like you'll probably be able to adapt the steps to suit your
needs and you've not actually told any of us what you're confused
about or still have a problem with.
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First, with the other list I'm on, simply doing a reply replies back to
the list. This one for some reason forwards the responders email for the
reply to. I was in a hurry and forgot to put the right address back
Next, you have now confused me with the part:
> You'll want the two types I specified for any boot device since it
> then appears to be a normal partition that happens to have an exact
Two types of what? To make both drives of the boot array bootable I have
been doing:
sudo grub
grub>device (hd0) /dev/sda
grub>root (hd0,0)
grub>setup (hd0)
grub>device (hd0) /dev/sdb
grub>root (hd0,0)
grub>setup (hd0)
That was done after the array was made. That worked for the other
computer I setup which has 2 sata drives and raid1 for all 3 partitions.
It has been booting ok for nearly a year. I did just update it from
lenny to testing and started the change to grub2. It is now booting
using chain to grub1.
And what I was asking about in the last message was when you said:
"For boot make SURE you use either -e 0.90 OR -e 1.0 ."
Are those mdadm switches to use older version methods?
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