RAID 1 on hp proliant ml110 g5

hector · Sep 28, 2011

Hello everybody!
I'm trying to configure a RAID 1 on a HP Proliant ml110 g5 server with FreeBSD 8.2. Is it possible to do it through hardware?

The server has two identical HDDs. I'd installed a running FreeBSD and I could see the disks as [ad0] and [ad2], then when I enabled the SATA RAID option on the BIOS and now the HDDs appears as [ad4] and [ad6]. I just changed the /etc/fstab file to match with the new HDD name and FreeBSD is still running. Does it mean that RAID 1 is running? How could I know it? Doesn't it have to show just one HDD?

Thank in advance.

mav@ · Sep 29, 2011

After enabling RAID in BIOS you should also create RAID volume there (be careful how to do it to not loose your data). After doing that you should find ar0 device on FreeBSD boot in addition to discrete ad4 and ad6 devices. That ar0 device is what you should use.

Sylhouette · Sep 29, 2011

You're probably going to lose your data when you create the mirror.

You could also create a gmirror of the drives. When doing so try to load the ahci module. In /boot/loader.conf add the line:

Code:

ahci_load="YES"

Your devices are then recognized as ada0 and ada1. I do not know if you use the hardware raid if the device changes when adding the ahci module. But be prepared to lose your data, so back up your data if you go the hardware raid way.

regards.
Johan Hendriks

hector · Sep 30, 2011

Thanks for answer...
I've just created the RAID 1 volume. It took about 6 hours!!! I did it with clearing method, I also set the volume as bootable and set the write cache too. Now when installing FreeBSD appears [ad4], [ad6], an finally [ar0]. I think tomorrow I'll install it.

Sylhouette: I had not important data in the server now, I'm installing from scratch.

Then I'll tell you how's going.

hector · Oct 4, 2011

Hello again, I'm here with another question. Is it possible to partition [ar0] into [ar0s1] and [ar0s2]?
Would RAID 1 volume work OK? Would it change the performance or something?

Sylhouette · Oct 5, 2011

You can use ar0 like any other disk. So partition all you want. There will be no extra performance penaties as far as I know.

regards
Johan

hector · Oct 6, 2011

Hello!
I just installed FreeBSD on ar0, the RAID 1 volume, and it seemed everything was ok. I made two partitions, one for the OS that I set as bootable, and the other one that I put different labels as I needed it. I have to say that the RAID 1 volume ar0 behaves like any drive, as Sylhouette said. The thing is that I get some disturbing messages on my logs when booting the system.

Code:

# cat /var/log/messages | egrep "ad4|ad6|ar0"
Oct  6 10:54:46 turing kernel: ad4: 476940MB <GB0500EAFJH HPGA> at ata2-master UDMA100 SATA 3Gb/s
Oct  6 10:54:46 turing kernel: ad6: 476940MB <ST500DM002 1BC142 JC4B> at ata3-master UDMA100 SATA 3Gb/s
Oct  6 10:54:46 turing kernel: GEOM: ad4s1: geometry does not match label (255h,63s != 16h,63s).
Oct  6 10:54:46 turing kernel: ar0: writing of DDF metadata is NOT supported yet
Oct  6 10:54:46 turing kernel: ar0: 476804MB <DDF RAID1> status: READY
Oct  6 10:54:46 turing kernel: ar0: disk0 READY (master) using ad4 at ata2-master
Oct  6 10:54:46 turing kernel: ar0: disk1 READY (mirror) using ad6 at ata3-master
Oct  6 10:54:46 turing kernel: GEOM: ad4s2: geometry does not match label (255h,63s != 16h,63s).
Oct  6 10:54:46 turing kernel: GEOM: ad6s1: geometry does not match label (255h,63s != 16h,63s).
Oct  6 10:54:46 turing kernel: GEOM: ad6s2: geometry does not match label (255h,63s != 16h,63s).
Oct  6 10:54:46 turing kernel: Trying to mount root from ufs:/dev/ar0s1a

Do I have to worry about that? Is there a way to fix it?

hector · Oct 6, 2011

This shows the not matching situation:

fdisk /dev/ad4

Code:

******* Working on device /dev/ad4 *******
parameters extracted from in-core disklabel are:
cylinders=969021 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=969021 heads=16 sectors/track=63 (1008 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 63, size 167766732 (81917 Meg), flag 80 (active)
	beg: cyl 0/ head 1/ sector 1;
	end: cyl 1023/ head 254/ sector 63
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 167766795, size 808728165 (394886 Meg), flag 0
	beg: cyl 1023/ head 255/ sector 63;
	end: cyl 1023/ head 254/ sector 63
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

fdisk /dev/ad6 shows exactly the same as on ad4

Code:

******* Working on device /dev/ad6 *******
parameters extracted from in-core disklabel are:
cylinders=969021 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=969021 heads=16 sectors/track=63 (1008 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 63, size 167766732 (81917 Meg), flag 80 (active)
	beg: cyl 0/ head 1/ sector 1;
	end: cyl 1023/ head 254/ sector 63
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 167766795, size 808728165 (394886 Meg), flag 0
	beg: cyl 1023/ head 255/ sector 63;
	end: cyl 1023/ head 254/ sector 63
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

fdisk /dev/ar0 on the RAID 1 volume

Code:

******* Working on device /dev/ar0 *******
parameters extracted from in-core disklabel are:
cylinders=60784 heads=255 sectors/track=63 (16065 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=60784 heads=255 sectors/track=63 (16065 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 63, size 167766732 (81917 Meg), flag 80 (active)
	beg: cyl 0/ head 1/ sector 1;
	end: cyl 1023/ head 254/ sector 63
The data for partition 2 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 167766795, size 808728165 (394886 Meg), flag 0
	beg: cyl 1023/ head 255/ sector 63;
	end: cyl 1023/ head 254/ sector 63
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

We can see the RAID 1 volume ar0 doesn't match in cylinders, heads, and blks/cyl values.

kpa · Oct 6, 2011

Last time heads and cylinders were meaningful was some some 10 years ago. Now that everything uses LBA addressing there is no way to determine the real geometry of a disk drive. I have no idea why FreeBSD still keeps those geometry checks in place, they serve absolutely no purpose anymore.