Nvidia MCP55 Raid Supported?

[spiffywiffy]

Hi All,

Gentoo 2007.0 hardened, kernel 2.6.21 on Tyan Transport GT24 with Thunder n3600R motherboard.

We have built a Raid 5 array using the Raid Bios but Gentoo only sees the drives individually. Does anyone know if this chipset is supported for Raid?

Thanks.

[NeddySeagoon]

spiffywiffy,

Welcome to Gentoo.

This sounds like a BIOS or fakeraid setup. It should be supported by dmraid. However, the only use for fakeraid is when both Windows and Linux must share the raid. If you are not doing that, use kernel raid.

To continue with fake raid, boot with the dodmraid option
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[spiffywiffy]

Hi NeddySeagoon:

First of all, thanks for the help.

Yes.. guess this is not true hardware RAID - boooo. We are only running Gentoo on this box, so kernel raid it is.

We are not attempting to boot from the array or run any of the O/S from the array. The array is only for /home at this point. So...

I restarted, disabled NVRAID in the BIOS and deleted the array that was built there. Our config is 1x74GB for OS, 3 x 500GB for RAID-5 /home -- all SATA.

emerged mdadm and ran:

mdadm --create --verbose /dev/md0 --level=5 --raid-devices=3 /dev/sdb /dev/sdc /dev/sdd

This was the output I received:

mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 64K
mdadm: size set to 488386496K
mdadm: array /dev/md0 started.

A current snapshot of /proc/mdstat:

Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sdd[3] sdc[1] sdb[0]
976772992 blocks level 5, 64k chunk, algorithm 2 [3/2] [UU_]
[==========>..........] recovery = 51.2% (250445696/488386496) finish=65.9min speed=60096K/sec

unused devices: <none>


So, everything appears to be chugging along. I assume the only remaining step is to add the new device to fstab, mtab and restart?

What's your opinion on write-intent bitmapping?

Thanks!

[NeddySeagoon]

spiffywiffy,

You should have created partitions on your drives to be raided, then raided the partitions. No matter, it works both ways provided you don't want root on the raid. Be aware that other raid users will be expecting you to have used partitions when you ask for advice.
e.g. auto starting the raid depends on the partitions being type 0xfd. As you don't have partition tables, you can't set partition types.

write-intent bitmapping is AGoodThing. It saves time when you get an unclean shutdown - only parts of the drive in the write-intent bitmap have to by synced, not the whole volume.

You only add the raid to /etc/fstab mtab is maintained by the mount command.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[spiffywiffy]

Yes, I realised that mistake after writing and did create partitions type fd. I actually did make them initially and forgot to "w"rite the table.

Everything is working great. Thanks.