Software RAID on Fedora

gh0st87 · 07-09-2011, 10:53 AM

Hi guys, our small server at work ran out of space so I bought two 3TB WD Caviars and I'm trying to create a RAID matrix.

I've created two gpt partitions with parted (and succeeded):

Code:

(parted) print
Model: ATA WDC WD30EZRX-00M (scsi)
Dysk /dev/sdd: 3001GB
Rozmiar sektora (logiczny/fizyczny): 512B/512B
Tablica partycji: gpt

Numer  Początek  Koniec  Rozmiar  System plików  Nazwa  Flaga
 1     17,4kB    3001GB  3001GB   ext3           vg01   lvm

Code:

(parted) print
Model: ATA WDC WD30EZRX-00M (scsi)
Dysk /dev/sdf: 3001GB
Rozmiar sektora (logiczny/fizyczny): 512B/512B
Tablica partycji: gpt

Numer  Początek  Koniec  Rozmiar  System plików  Nazwa  Flaga
 1     17,4kB    3001GB  3001GB   ext3           vg02   lvm

Now I'm trying to include these two partitions in a RAID1 matrix, this is the command I'm using and the output:

Code:

[root@ftp2 ~]# mdadm -C -v /dev/md2 --level=1 -n 2 /dev/sdd1 /dev/sdf1
mdadm: Defaulting to version 1.-1 metadata
mdadm: /dev/sdd1 appears to contain an ext2fs file system
    size=-1364700748K  mtime=Sat Jul  9 15:52:45 2011
mdadm: /dev/sdf1 appears to contain an ext2fs file system
    size=-1364700748K  mtime=Thu Jan  1 01:00:00 1970
mdadm: size set to 2930266412K
Continue creating array? y
mdadm: ADD_NEW_DISK for /dev/sdd1 failed: Device or resource busy

the /dev/sdd1 is not mounted anywhere

Code:

[root@ftp2 ~]# umount -l /dev/sdd1
umount: /dev/sdd1: not mounted
[root@ftp2 ~]# umount -l /dev/sdf1
umount: /dev/sdf1: not mounted

I've ran partprobe just in case - still nothing.

What am I missing? I'm running:
Linux version 2.6.26.8-57.fc8 (mockbuild@x86-3.fedora.phx.redhat.com) (gcc version 4.1.2 20070925 (Red Hat 4.1.2-33)) #1 SMP Thu Dec 18 19:19:45 EST 2008

jefro · 07-09-2011, 12:12 PM

I don't get the reason for this. Why make a raid on a single disk? About the only use software raid has is to create a mirror on two disks. It is not very fast or useful for any other use.

gh0st87 · 07-09-2011, 12:16 PM

I'm not creating a RAID on a single disk.
I have /dev/sdd with /dev/sdd1 and /dev/sdf with /dev/sdf1 and I'm trying to create a RAID1 with /dev/sdd1 & /dev/sdf1.

ok, an update:

Code:

[root@ftp2 ~]# mkfs.ext3 /dev/sdf1
mke2fs 1.40.4 (31-Dec-2007)
Etykieta systemu plików=
Typ OS: Linux
Rozmiar bloku=4096 (log=2)
Rozmiar fragmentu=4096 (log=2)
366280704 i-węzłów, 732556876 bloków
36627843 bloków (5.00%) zarezerwowanych dla superużytkownika
Pierwszy blok danych=0
Maksymalna liczba bloków systemu plików=0
22356 grup bloków
32768 bloków w grupie, 32768 fragmentów w grupie
16384 i-węzłów w grupie
Kopie zapasowe superbloku zapisane w blokach:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000, 214990848, 512000000, 550731776, 644972544

Zapis tablicy i-węzłów: zakończono
Tworzenie kroniki (32768 bloków): wykonano
Zapis superbloków i podsumowania systemu plików: wykonano

Ten system plików będzie automatycznie sprawdzany co każde 32 montowań
lub co 180 dni, zależnie co nastąpi pierwsze. Można to zmienić poprzez
tune2fs -c lub -i.
[root@ftp2 ~]# mdadm -C -v /dev/md2 --level=1 -n 2 /dev/sdd1 /dev/sdf1
mdadm: /dev/sdd1 is too small: 0K
mdadm: /dev/sdf1 appears to contain an ext2fs file system
    size=-1364739792K  mtime=Thu Jan  1 01:00:00 1970
mdadm: create aborted

Sorry for the Polish output from mkfs, but: according to mdadm, 41 years ago I've created a partition with negative size.

WTH?

rtguille · 07-11-2011, 05:28 PM

After creating the partitions with parted, did you execute 'partprobe'?

# partprobe /dev/sd{d,e}

Since you created a 3TB partition, i will asume that the hard disks were partitioned as GPT

The tool to use for GPT disks is gdisk or parted and not fdisk. (you used parted).

# gdisk -l /dev/sd{d,e}

The GPT partitions for mdadm usage should be type FD00. (linux raid)
The GPT normal data partiton type is 0700 and for swap 8200.