Should the following be possible: make a raid-1 with 2 disks, on top of that put lvm and after that create some filesystems in the volume group. I especially wonder about the lvm on top of the raid. I tried to do that with yast, but yast does not seem to be able to do that. I can configure the raid, I can go to create lvm -> but it shows the only the physical devices and not the raid. Is this a limit in yast? Is there a workaround? -- Richard Bos Without a home the journey is endless
On Thursday 19 May 2005 05:05 pm, Richard Bos wrote:
Should the following be possible:
make a raid-1 with 2 disks, on top of that put lvm and after that create some filesystems in the volume group.
I especially wonder about the lvm on top of the raid. I tried to do that with yast, but yast does not seem to be able to do that.
I can configure the raid, I can go to create lvm -> but it shows the only the physical devices and not the raid. Is this a limit in yast? Is there a workaround?
-- Richard Bos Without a home the journey is endless
The short answer is ... yes. You don't say which version of SuSE you are using. I was very happy to see the 9.3 installer handle this perfectly. In previous versions it would switch the boot loader to Lilo and/or have trouble with this combination. I would set this up manually using a method I've posted here in the past. When you created the RAID device, did you format it (you shouldn't)? If the RAID device is unformated and unmounted, the Yast LVM module should show it as a usable device. This does all work through Yast. -- Louis Richards
On Fri, May 20, 2005 at 08:06:24AM -0400, Louis Richards wrote:
On Thursday 19 May 2005 05:05 pm, Richard Bos wrote:
Should the following be possible:
make a raid-1 with 2 disks, on top of that put lvm and after that create some filesystems in the volume group.
I especially wonder about the lvm on top of the raid. I tried to do that with yast, but yast does not seem to be able to do that.
I can configure the raid, I can go to create lvm -> but it shows the only the physical devices and not the raid. Is this a limit in yast? Is there a workaround?
-- Richard Bos Without a home the journey is endless
The short answer is ... yes.
Good to know, that I'm on the right path :)
You don't say which version of SuSE you are using. I was very happy to see the 9.3 installer handle this perfectly. In previous versions it would switch the
It's suse-9.3
boot loader to Lilo and/or have trouble with this combination. I would set this up manually using a method I've posted here in the past.
Can you post it again?
When you created the RAID device, did you format it (you shouldn't)? If the RAID device is unformated and unmounted, the Yast LVM module should show it as a usable device.
This does all work through Yast.
It's during initial installation, so nothing is there it's all virtual.I have to devices hda and hdc. I assign both (the whole disk for the moment) to the raid. This works fine. After that I start to create the lvm. This pops up a window telling that there are no devices left for the lvm. It does not "see" the /dev/md0 device :( Should lvm see the /dev/md0 device? -- Richard
On Friday 20 May 2005 08:44 am, radoeka wrote: <SNIP>
It's during initial installation, so nothing is there it's all virtual.I have to devices hda and hdc. I assign both (the whole disk for the moment) to the raid. This works fine. After that I start to create the lvm. This pops up a window telling that there are no devices left for the lvm. It does not "see" the /dev/md0 device :( Should lvm see the /dev/md0 device?
-- Richard
Your going to need to create more partitions. Your boot partition and swap will not be LVM. Create three partitions on each drive. The suggested scheme will give you an idea as to what size to make the swap partition, probably 1G. I used 100M for my /boot device and it is plenty. You will end up with 3 RAID devices. make one formated for swap, one /boot and formated (reiser or ext3), and a third device that is not formated or mounted anywhere. If your RAID device is formated and/or given a mount point, it will not show up in LVM. It's hard to tell from here, but I'm guessing your RAID device is listed as mounting at /. I think this is the default. Change this to be blank. I just installed 9.3 to a system with three disks and software RAID 5. I made three partitions on each disk. I did this to end up with three large equal sized partitions. hda1 and hdb1 = /dev/mdo = /boot hdc1 and hda2 = /dev/md1 = swap hdb1 and hdc2 = /dev/md2 = swap hda3 and hdb3 and hdc3 = /dev/md3 = LVM = / (RAID 5) HTH, -- Louis Richards
On Fri, 2005-05-20 at 16:08 -0400, Louis Richards wrote:
On Friday 20 May 2005 08:44 am, radoeka wrote: <SNIP>
Your going to need to create more partitions. Your boot partition and swap will not be LVM. Create three partitions on each drive. The suggested scheme will give you an idea as to what size to make the swap partition, probably 1G. I used 100M for my /boot device and it is plenty. You will end up with 3 RAID devices. make one formated for swap, one /boot and formated (reiser or ext3), and a third device that is not formated or mounted anywhere. If your RAID device is formated and/or given a mount point, it will not show up in LVM.
It's hard to tell from here, but I'm guessing your RAID device is listed as mounting at /. I think this is the default. Change this to be blank.
I just installed 9.3 to a system with three disks and software RAID 5. I made three partitions on each disk. I did this to end up with three large equal sized partitions.
hda1 and hdb1 = /dev/mdo = /boot hdc1 and hda2 = /dev/md1 = swap hdb1 and hdc2 = /dev/md2 = swap hda3 and hdb3 and hdc3 = /dev/md3 = LVM = / (RAID 5)
You really should not put swap into a software raid as it will actually make swap run slower and since there is no filesystem in swap that needs saving why bother. YMMV -- Ken Schneider UNIX since 1989, linux since 1994, SuSE since 1998 "The day Microsoft makes something that doesn't suck is probably the day they start making vacuum cleaners." -Ernst Jan Plugge
Ken Schneider wrote:
On Fri, 2005-05-20 at 16:08 -0400, Louis Richards wrote:
On Friday 20 May 2005 08:44 am, radoeka wrote: <SNIP>
Your going to need to create more partitions. Your boot partition and swap will not be LVM. Create three partitions on each drive. The suggested scheme will give you an idea as to what size to make the swap partition, probably 1G. I used 100M for my /boot device and it is plenty. You will end up with 3 RAID devices. make one formated for swap, one /boot and formated (reiser or ext3), and a third device that is not formated or mounted anywhere. If your RAID device is formated and/or given a mount point, it will not show up in LVM.
It's hard to tell from here, but I'm guessing your RAID device is listed as mounting at /. I think this is the default. Change this to be blank.
I just installed 9.3 to a system with three disks and software RAID 5. I made three partitions on each disk. I did this to end up with three large equal sized partitions.
hda1 and hdb1 = /dev/mdo = /boot hdc1 and hda2 = /dev/md1 = swap hdb1 and hdc2 = /dev/md2 = swap hda3 and hdb3 and hdc3 = /dev/md3 = LVM = / (RAID 5)
You really should not put swap into a software raid as it will actually make swap run slower and since there is no filesystem in swap that needs saving why bother. YMMV
I hear the advice quoted often, with varying volume, about the pros and cons of putting swap on RAID. While yes, performance will be less (as it would generally be with most (equal reads and writes, etc) types of software RAID), it ~will~ save you from a crash should you lose a disk holding the swap. The data in swap ~does~ need saving as long as the machine is running and swapping. -- --Moby They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety. -- Benjamin Franklin First they came for the Jews and I did not speak out because I was not a Jew. Then they came for the Communists and I did not speak out because I was not a Communist. Then they came for the trade unionists and I did not speak out because I was not a trade unionist. Then they came for me and there was no one left to speak out for me. -- Pastor Martin Niemöller
Op vrijdag 20 mei 2005 22:08, schreef Louis Richards:
It's hard to tell from here, but I'm guessing your RAID device is listed as mounting at /. I think this is the default. Change this to be blank.
This is the one! After this I could start configuring the LVM.
hdc1 and hda2 = /dev/md1 = swap hdb1 and hdc2 = /dev/md2 = swap
BTW: why do you have 2 swaps and not just 1?
hda1 and hdb1 = /dev/mdo = /boot hda3 and hdb3 and hdc3 = /dev/md3 = LVM = / (RAID 5)
According to the suse documentation and guidelines in yast sideline, the "/" partition should not be on LVM. In your case "/" is on LVM, what /boot isn't. Should I conclude from that, that the suse documentation should be read as the /boot partition should not be on LVM? I can imagine that it is better/safer to have "/" not on LVM, it prevents an additional layer that can break... -- Richard Bos Without a home the journey is endless
On Friday 20 May 2005 05:01 pm, Richard Bos wrote:
Op vrijdag 20 mei 2005 22:08, schreef Louis Richards:
It's hard to tell from here, but I'm guessing your RAID device is listed as mounting at /. I think this is the default. Change this to be blank.
This is the one! After this I could start configuring the LVM.
Great! I'm glad that you got it going.
hdc1 and hda2 = /dev/md1 = swap hdb1 and hdc2 = /dev/md2 = swap
BTW: why do you have 2 swaps and not just 1?
Well, there are lots of differing thoughts on swap setups. I would love to claim some fancy technical reason for this setup, but I can't. I had three drives and RAID requires equal sized partitions. A single boot and a swap is two partitions. A single swap and two swaps is three. This was simply easier to make even sized mirrors across the three drives. My boot device ended up being larger than needed, but that's OK.
hda1 and hdb1 = /dev/mdo = /boot hda3 and hdb3 and hdc3 = /dev/md3 = LVM = / (RAID 5)
According to the suse documentation and guidelines in yast sideline, the "/" partition should not be on LVM. In your case "/" is on LVM, what /boot isn't. Should I conclude from that, that the suse documentation should be read as the /boot partition should not be on LVM?
I can imagine that it is better/safer to have "/" not on LVM, it prevents an additional layer that can break...
I have not had a problem using RAID and/or LVM on the root partition as long as boot is separate (boot can be RAID 1 at most AFAIK). You will hear even more ideas on partitioning than you will about swap setups. Unfortunately, there are valid reasons for most of the setups, making the decisions harder. LVM has made it easier to go with simpler schemes. Depending on how you plan to use this machine, you should probably at least create a home partition as well. This will make future upgrades much easier. The above setup was used on a machine that mounted home from another machine.
-- Richard Bos Without a home the journey is endless
-- Louis Richards It's not the destination ... it's the ride.
participants (5)
-
Ken Schneider -
Louis Richards -
Moby -
radoeka -
Richard Bos