Q1. How to scan newly luns in linux?
1. Identify the existing disks
fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l
2. 2. Identify the number of adapters
# ls /sys/class/fc_host
host0 host1 host2 host3
scan the LUNs
echo "- - -" > /sys/class/scsi_host/host0/scan
echo "- - -" > /sys/class/scsi_host/host1/scan
3. Identify the new disks
fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l
Q2. How to create Software RAID 1 array?
1. Identify disks in system. I have used /dev/sdd /dev/sde disk for raid1 array.
RAID 1 uses redundancy with mirroring.
[root@linux01 ~]# fdisk -l
Disk /dev/sdd: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdd doesn't contain a valid partition table
Disk /dev/sde: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sde doesn't contain a valid partition table
2. Create raid array using mdadm command
[root@linux01 ~]# mdadm --create /dev/md0 --level=raid1 --raid-devices=2 /dev/sdd /dev/sde
mdadm: array /dev/md0 started.
[root@linux01 ~]#
To verify raid status:
[root@linux01 ~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sde[1] sdd[0]
2097088 blocks [2/2] [UU]
unused devices: <none>
We can format and mount disk /dev/md0
Q3. How to create LVM partition Software RAID 1 array?
We can create LVM partition on /dev/md0. Refer Q2 for creating raid 1 array.
[root@linux01 ~]# pvcreate /dev/md0
Physical volume "/dev/md0" successfully created
[root@linux01 ~]# pvs
/dev/hdc: open failed: No medium found
PV VG Fmt Attr PSize PFree
/dev/md0 lvm2 a- 2.00G 2.00G
/dev/sda2 VolGroup00 lvm2 a- 9.88G 0
[root@linux01 ~]# vgcreate -n raidvg /dev/md0
vgcreate: invalid option -- n
Error during parsing of command line.
[root@linux01 ~]# vgcreate raidvg /dev/md0
Volume group "raidvg" successfully created
[root@linux01 ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 7.88G
LogVol01 VolGroup00 -wi-ao 2.00G
[root@linux01 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup00 1 2 0 wz--n- 9.88G 0
raidvg 1 0 0 wz--n- 2.00G 2.00G
[root@linux01 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/md0 raidvg lvm2 a- 2.00G 2.00G
/dev/sda2 VolGroup00 lvm2 a- 9.88G 0
[root@linux01 ~]# lvcreate -L 500M -n raidlv01 /dev/raidvg
Logical volume "raidlv01" created
[root@linux01 ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 7.88G
LogVol01 VolGroup00 -wi-ao 2.00G
raidlv01 raidvg -wi-a- 500.00M
[root@linux01 ~]# mkfs -t ext3 /dev/raidvg/raidlv01
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
128016 inodes, 512000 blocks
25600 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67633152
63 block groups
8192 blocks per group, 8192 fragments per group
2032 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@linux01 ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
LogVol00 VolGroup00 -wi-ao 7.88G
LogVol01 VolGroup00 -wi-ao 2.00G
raidlv01 raidvg -wi-a- 500.00M
[root@linux01 ~]# mount /dev/raidvg/raidlv01 /mnt
[root@linux01 ~]# df -hP
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00 7.7G 6.4G 915M 88% /
/dev/sda1 99M 14M 81M 15% /boot
tmpfs 440M 0 440M 0% /dev/shm
none 440M 104K 440M 1% /var/lib/xenstored
/dev/mapper/raidvg-raidlv01 485M 11M 449M 3% /mnt
No comments:
Post a Comment