Dotaz: LVM RAID1 recovery

[BigWrigley]

Příloha:

• Screenshot--dev-sdb - GParted.png (58326 bytů)

Zdravim,

kolegovi odeslo do kremikoveho nebe toto: http://support.wdc.com/product/kb.asp?groupid=901&lang=en - 2TB verze se dvema disky po 1TB. Disky jsou, jak se zda OK. Protoze jsem si zatim s LVM jen hral a tady je to navic s raidem, chtel bych pozadat o radu, jak postupovat pri obnove. Pokud by to byl jen raid, bylo by to snadne, s LVM potrebuji postouchnout.

Partition table jednoho disku vypada takto: (priloha) Obnova bude probihahat na Ubuntu 9.04 serverova verze, vzdalene, kolega mi pripoji disky do ssh pristupneho pc.

Mate nejaka doporuceni? Lze to vubec obnovit? Predpokladam, ze ano.

Diky vsem.

Ales

Odpovědi

[BigWrigley]

Oprava linku: http://support.wdc.com/product/kb.asp?groupid=901

[iji]

Zajima te particie /dev/sdb4.
Pokud bude disk pripojeny pri bootu, LVM si konfiguraci z disku "slizne" samo, pokud se pripoji za chodu (pres USB box), staci spustit vgscan. Po tomto kroku by melo LVM vedet o preparovanem disku, overit pres vgdisplay (popripade pvdisplay). Muze se stat, ze LV v VG nebudou dostupne, coz se zmeni pres vgchange -a y /dev/jmeno_gorupy/jmeno_volume. Pak uz jen staci klasicky mount pro jistotu jen read only a data prekopirovat jinam. mount si bude nejspise schopen sam zjistit typ FS z hlavicky LV.

Disky lze samozdrejme pouzivat v tomto "docasnem" stavu navzdy, jsou to obycejne desktop disky.

[BigWrigley]

A co kdyz vubec vgscan ten pripojeny disk vubec nevidi a zobrazuje jen stavajici konfiguraci LVM, ktera je pouzita v tom Ubuntu? Da se nejak "postvat" na konkretni disk?

root@komp:~# vgdisplay
  --- Volume group ---
  VG Name               komp
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               148.81 GB
  PE Size               4.00 MB
  Total PE              38095
  Alloc PE / Size       38095 / 148.81 GB
  Free  PE / Size       0 / 0
  VG UUID               5GuAOx-1uVM-0Vgm-U0Ro-Kl21-iZyl-QvLZtF

root@komp:~#                                                  

[BigWrigley]

Jinak fdisk reportuje toto:

root@komp:~# fdisk -l  /dev/sda

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x233b355b

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1          26      208844+  fd  Linux raid autodetect
/dev/sda2              27         156     1044225   fd  Linux raid autodetect
/dev/sda3             157         182      208845   fd  Linux raid autodetect
/dev/sda4             183      121601   975298117+  fd  Linux raid autodetect

[BigWrigley]

A podarilo se mi primountovat sda1, kde v konfiguraci LVM /etc/lvm/backup je toto

            Line 1 Col 0       1046 bytes                                                                  100%
# Generated by LVM2: Wed Apr  1 15:20:30 2009

contents = "Text Format Volume Group"
version = 1

description = "Created *after* executing '/sbin/lvcreate -l 238060 -n lv0 vg0'"

creation_host = "WDShareSpace"  # Linux WDShareSpace 2.6.12.6-arm1 #30 Wed Nov 12 14:45:36 CST 2008 armv5tejl
creation_time = 1238592030      # Wed Apr  1 15:20:30 2009

vg0 {
        id = "HnF29L-nv4X-Qo4V-Ap6Q-TTqX-EYFk-hLEu8Q"
        seqno = 2
        status = ["RESIZEABLE", "READ", "WRITE"]
        extent_size = 8192              # 4 Megabytes
        max_lv = 255
        max_pv = 255

        physical_volumes {

                pv0 {
                        id = "i1usil-1vIi-LeWT-lgRs-w45V-hYby-S5cXf1"
                        device = "/dev/md2"     # Hint only

                        status = ["ALLOCATABLE"]
                        pe_start = 384
                        pe_count = 238060       # 929.922 Gigabytes
                }
        }

        logical_volumes {

                lv0 {
                        id = "5y2wwd-5OQN-vTwj-u3yV-la1o-nV5W-aKCYEn"
                        status = ["READ", "WRITE", "VISIBLE"]
                        segment_count = 1

                        segment1 {
                                start_extent = 0
                                extent_count = 238060   # 929.922 Gigabytes

                                type = "striped"
                                stripe_count = 1        # linear

                                stripes = [
                                        "pv0", 0
                                ]
                        }
                }
        }
}

[BigWrigley]

Tak vyreseno.

Postup byl nasledujici:

Nejdrive bylo nutne zprovoznit RAID1 alespon v degradovanem modu:

- scan raid partition:

mdadm --examine --scan /dev/sda4 >> /etc/mdadm/mdadm.conf

ARRAY /dev/md2 level=raid1 num-devices=2 UUID=c1bdd68c:f39cfb85:9de312f2:55a71978

- nastartovani raid zarizeni

mdadm -A -s

Vypis stavu raid zarizeni:

cat /proc/mdstat

root@komp:~# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sda4[0]
      975097920 blocks [2/1] [U_]

unused devices: none

lvmdiskscan uz pote vidi /dev/md2 jako LVM zarizeni

root@komp:~# lvmdiskscan
  /dev/ram0        [       64.00 MB]
  /dev/komp/root   [      145.94 GB]
  /dev/ram1        [       64.00 MB]
  /dev/komp/swap_1 [        2.87 GB]
  /dev/ram2        [       64.00 MB]
  /dev/md2         [      929.93 GB] LVM physical volume
  /dev/vg0/lv0     [      929.92 GB]
  /dev/ram3        [       64.00 MB]
  /dev/sda3        [      203.95 MB]
  /dev/ram4        [       64.00 MB]
  /dev/ram5        [       64.00 MB]
  /dev/ram6        [       64.00 MB]
  /dev/ram7        [       64.00 MB]
  /dev/ram8        [       64.00 MB]
  /dev/ram9        [       64.00 MB]
  /dev/ram10       [       64.00 MB]
  /dev/ram11       [       64.00 MB]
  /dev/ram12       [       64.00 MB]
  /dev/ram13       [       64.00 MB]
  /dev/ram14       [       64.00 MB]
  /dev/ram15       [       64.00 MB]
  /dev/sdb1        [      148.81 GB] LVM physical volume
  /dev/sdb5        [      243.14 MB]
  1 disk
  20 partitions
  0 LVM physical volume whole disks
  2 LVM physical volumes

Nasleduje vgascan:

root@komp:~# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "komp" using metadata type lvm2
  Found volume group "vg0" using metadata type lvm2
root@komp:~#                                         

Pote vgdisplay

root@komp:~# vgdisplay vg0
  --- Volume group ---
  VG Name               vg0
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                255
  Cur LV                1
  Open LV               1
  Max PV                255
  Cur PV                1
  Act PV                1
  VG Size               929.92 GB
  PE Size               4.00 MB
  Total PE              238060
  Alloc PE / Size       238060 / 929.92 GB
  Free  PE / Size       0 / 0
  VG UUID               HnF29L-nv4X-Qo4V-Ap6Q-TTqX-EYFk-hLEu8Q

root@komp:~#                                         

A pak uz jen namountovat (pro jistotu ro):

mount -o ro /dev/mapper/vg0-lv0 /disk4

A data vykopirovat....

Ales

[jsmach]

díky moc za návod, klekl mi HD s LVM a už jsem obrečel data, naštěstí se mi je podle thoto návodu podařilo bez problému dostat na jiný disk-