Red Hat GLOBAL FILE SYSTEM 5.0, Руководство администратора

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/dev/sdb1(0)
[groupfs_mlog] vg lwi-ao 4.00M
/dev/sdc1(0)
[root@link-08 ~]# lvs -a -o +devices
LV VG Attr LSize Origin Snap% Move Log
Copy% Devices
groupfs vg mwi-a- 752.00M groupfs_mlog
100.00 groupfs_mimage_0(0),groupfs_mimage_1(0)
[groupfs_mimage_0] vg iwi-ao 752.00M
/dev/sda1(0)
[groupfs_mimage_1] vg iwi-ao 752.00M
/dev/sdb1(0)
[groupfs_mlog] vg lwi-ao 4.00M i
/dev/sdc1(0)
In this example, the primary leg of the mirror
/dev/sda1
fails. Any write activity to the mirrored
volume causes LVM to detect the failed mirror. When this occurs, LVM converts the mirror into a
single linear volume. In this case, to trigger the conversion, we execute a
dd
command
[root@link-08 ~]# dd if=/dev/zero of=/dev/vg/groupfs count=10
10+0 records in
10+0 records out
You can use the
lvs
command to verify that the device is now a linear device. Because of the
failed disk, I/O errors occur.
[root@link-08 ~]# lvs -a -o +devices
/dev/sda1: read failed after 0 of 2048 at 0: Input/output error
/dev/sda2: read failed after 0 of 2048 at 0: Input/output error
LV VG Attr LSize Origin Snap% Move Log Copy% Devices
groupfs vg -wi-a- 752.00M /dev/sdb1(0)
At this point you should still be able to use the logical volume, but there will be no mirror
redundancy.
To rebuild the mirrored volume, you replace the broken drive and recreate the physical volume.
If you use the same disk rather than replacing it with a new one, you will see "inconsistent"
warnings when you run the
pvcreate
command.
[root@link-08 ~]# pvcreate /dev/sda[12]
Physical volume "/dev/sda1" successfully created
Physical volume "/dev/sda2" successfully created
[root@link-08 ~]# pvscan
PV /dev/sdb1 VG vg lvm2 [67.83 GB / 67.10 GB free]
PV /dev/sdb2 VG vg lvm2 [67.83 GB / 67.83 GB free]
PV /dev/sdc1 VG vg lvm2 [67.83 GB / 67.83 GB free]
Chapter 6. LVM Troubleshooting
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