Formatting multi-disk raid config 6TB

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The.Ex-pat
Posts: 22
Joined: 2019/06/21 00:07:29

Formatting multi-disk raid config 6TB

Post by The.Ex-pat » 2020/07/11 05:36:42

I'm attempting to setup a 2 disk, raid 0, 6TB in size.

# fdisk -l

Code: Select all

Disk /dev/sda: 31.7 GB, 31675383808 bytes, 61865984 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000e8bf9

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    61865983    29883392   8e  Linux LVM

Disk /dev/sdc: 3000.6 GB, 3000592982016 bytes, 5860533168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1  4294967295  2147483647+  ee  GPT

Disk /dev/mapper/centos-root: 27.4 GB, 27426553856 bytes, 53567488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/centos-swap: 3166 MB, 3166699520 bytes, 6184960 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.

Disk /dev/mapper/nvidia_cfdeaaic: 6001.2 GB, 6001185914880 bytes, 11721066240 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 65536 bytes / 131072 bytes
Disk label type: gpt
Disk identifier: 8C0EA435-5042-4F21-ABC7-DA59DA42A0CC


#         Start          End    Size  Type            Name
 1         2048  11721064447    5.5T  Microsoft basic primary
the system is showing a 3TB drive @ sbc
I'm also seeing what I assume is the RAID formation @ /dev/mapper/nvidia_cfdeaaic

# parted /dev/mapper/nvidia_cfdeaaic
worked and I was able to set a single 6TB partition.

However, I can't get mkfs to format and xfs file system on that parititon

# mkfs.xfs /dev/mapper/nvidia_cfdeaaic

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mkfs.xfs: cannot open /dev/mapper/nvidia_cfdeaaic: Device or resource busy
I'm not sure what to do.... Also, I normally use # blkid and find the uuid to setup the entry in fstab. This array is not showing a uuid. I'm stumped dudes.

Edit:

Web search keeps giving me stuff about disabling the multi path.
# multipath -ll

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Jul 11 10:06:34 | DM multipath kernel driver not loaded
Jul 11 10:06:34 | /etc/multipath.conf does not exist, blacklisting all devices.
Jul 11 10:06:34 | A default multipath.conf file is located at
Jul 11 10:06:34 | /usr/share/doc/device-mapper-multipath-0.4.9/multipath.conf
Jul 11 10:06:34 | You can run /sbin/mpathconf --enable to create
Jul 11 10:06:34 | /etc/multipath.conf. See man mpathconf(8) for more details
Jul 11 10:06:34 | DM multipath kernel driver not loaded
I still can't seem to get anywhere with it.

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TrevorH
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Re: Formatting multi-disk raid config 6TB

Post by TrevorH » 2020/07/11 16:24:13

Start over. Go into your BIOS and turn off RAID in the setup for these disks. You may then need to use the dmraid -E -r command (check the man page for the correct syntax, do not trust my memory!) to remove the FakeRAID metadata from the disks before they can be used again. Once that's done you should see your disks as /dev/sd$whatever but when you try to use mdadm to create an array, it should be called something like /dev/md0 not /dev/mapper/nvidia_cfdeaaic which is an indicator that FakeRAID is in use.
CentOS 6 died in November 2020 - migrate to a new version!
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 is dead, do not use it.
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The.Ex-pat
Posts: 22
Joined: 2019/06/21 00:07:29

Re: Formatting multi-disk raid config 6TB

Post by The.Ex-pat » 2020/07/11 16:58:00

TrevorH wrote:
2020/07/11 16:24:13
Start over. Go into your BIOS and turn off RAID in the setup for these disks. You may then need to use the dmraid -E -r command (check the man page for the correct syntax, do not trust my memory!) to remove the FakeRAID metadata from the disks before they can be used again. Once that's done you should see your disks as /dev/sd$whatever but when you try to use mdadm to create an array, it should be called something like /dev/md0 not /dev/mapper/nvidia_cfdeaaic which is an indicator that FakeRAID is in use.
I'm going to do this, because obviously you know what your talking about, however I have a question about it.

I've always understood that you want to setup "Hardware Raid". In the hardware configuration. As it's "Faster" operationally.
Is this just some windows user garbage that's not true? I'm not questioning you, I'm trying to educate myself.

Thanks in advance

edit:
-r | --raid_devices
-E | --erase_metadeta
Last edited by The.Ex-pat on 2020/07/11 17:06:21, edited 1 time in total.

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TrevorH
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Re: Formatting multi-disk raid config 6TB

Post by TrevorH » 2020/07/11 17:04:51

The RAID you get on consumer motherboards is not hardware RAID, it's FakeRAID. All the RAID stuff is done in software, in the drivers in use on the operating system. On hardware RAID cards you have dedicated on-board processors and RAM that are used to help calculate the checksums etc needed to do RAID and to cache the data that is written (hopefully battery backed so it doesn't get lost on power failure). FakeRAID has none of these.
CentOS 6 died in November 2020 - migrate to a new version!
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 is dead, do not use it.
Full time Geek, part time moderator. Use the FAQ Luke

The.Ex-pat
Posts: 22
Joined: 2019/06/21 00:07:29

Re: Formatting multi-disk raid config 6TB

Post by The.Ex-pat » 2020/07/11 17:07:12

TrevorH wrote:
2020/07/11 17:04:51
The RAID you get on consumer motherboards is not hardware RAID, it's FakeRAID. All the RAID stuff is done in software, in the drivers in use on the operating system. On hardware RAID cards you have dedicated on-board processors and RAM that are used to help calculate the checksums etc needed to do RAID and to cache the data that is written (hopefully battery backed so it doesn't get lost on power failure). FakeRAID has none of these.
Copy that. Thank you.

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