[ale] LVM: fumble fingered idiot problem

Dow Hurst dphurst at uncg.edu
Fri Sep 7 13:21:30 EDT 2012


Matt,
You've had to deal with LVM a lot more than I have so I'm asking for some
thoughts.  I plugged up an external USB drive to the fileserver to create a
partition table, format, and copy data over on to the USB drive.  Well, I
looked at /proc/partitions and ran fdisk on /dev/sda instead of the right
device, /dev/sdd.  I created a DOS partition table, created a single
primary partition, synced and exited fdisk.  Then, I realized that /dev/sdd
was the right device and it already had partitions and data.  Great.  So,
I'm trying to figure out what the hell I just did to the file server.  It's
still up and running but a reboot would probably be disastrous.  Anyway I
have several pieces of data below relating to the devices, partitions, and
lvm data.  I may have wiped out the system lvm data off of /dev/sda.  The
fs1 volume shows but the system volume doesn't.  Does that make sense?  Is
there a way to rewrite the lvm data?  Just remember that /dev/sda didn't
have any partition table or partition, as shown below, before this moment.
 I also think that the devices dm-0, sda, and lvm system are the same
filesystem/devices that make up the /home where all the critical data is.
 Sure, I have backups of the most important user directories using bacula,
but not a mirror copy of everything as is.  I have archived copies of older
data that would make up the difference, but what a stupid pain to have
committed.  I'm wondering if this can be like grub, where reinstalling the
master boot record doesn't harm the system.  How do you rewrite the lvm
data without wiping out the mounted filesystem?

Ubuntu 8.04

//fs1> show

Ctl   Model        (V)Ports  Drives   Units   NotOpt  RRate   VRate  BBU
------------------------------------------------------------------------
c0    9550SXU-8LP  8         8        3       0       1       3      -
//fs1> /c0 show

Unit  UnitType  Status         %RCmpl  %V/I/M  Stripe  Size(GB)  Cache
 AVrfy
------------------------------------------------------------------------------
u0    RAID-5    VERIFY-PAUSED  -       0       64K     1862.61   ON     ON

u1    SINGLE    VERIFY-PAUSED  -       0       -       465.651   ON     ON

u2    RAID-1    VERIFY-PAUSED  -       0       -       232.82    ON     ON


Port   Status           Unit   Size        Blocks        Serial
---------------------------------------------------------------
p0     OK               u0     465.76 GB   976773168     WD-WCANU1733818

p1     OK               u0     465.76 GB   976773168     WD-WCANU1733754

p2     OK               u0     465.76 GB   976773168     WD-WCANU1735394

p3     OK               u0     465.76 GB   976773168     WD-WCANU1888007

p4     OK               u0     465.76 GB   976773168     WD-WCANU1735961

p5     VERIFYING        u1     465.76 GB   976773168     WD-WCANU1731650

p6     OK               u2     233.76 GB   490234752     WD-WCANY2372724

p7     OK               u2     233.76 GB   490234752     WD-WCANY2774785

root at fs1:/etc/lvm/backup# cat /proc/partitions
major minor  #blocks  name

   8     0 1953083392 sda
   8     1 1953078246 sda1
   8    16  488270848 sdb
   8    32  244129792 sdc
   8    33     248976 sdc1
   8    34          1 sdc2
   8    37  243874701 sdc5
 254     0 1932738560 dm-0
 254     1  240799744 dm-1
 254     2    3072000 dm-2
   8    48  488386584 sdd
   8    49  488384001 sdd1

root at fs1:/etc/lvm/backup# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/fs1-root  228G   17G  201G   8% /
varrun                501M   84K  501M   1% /var/run
varlock               501M     0  501M   0% /var/lock
udev                  501M   68K  501M   1% /dev
devshm                501M     0  501M   0% /dev/shm
/dev/sdc1             236M   26M  198M  12% /boot
/dev/mapper/system-home
                      1.8T  1.7T   71G  96% /home
/dev/sdd1             459G   18G  418G   5% /mnt

root at fs1:/etc/lvm/backup# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sdc5
  VG Name               fs1
  PV Size               232.58 GB / not usable 2.89 MB
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              59539
  Free PE               0
  Allocated PE          59539
  PV UUID               PjgniS-zP39-TvRu-EabS-wv1Q-Un5g-ROMg6c


root at fs1:~/tw# pvdisplay -m
  --- Physical volume ---
  PV Name               /dev/sdc5
  VG Name               fs1
  PV Size               232.58 GB / not usable 2.89 MB
  Allocatable           yes (but full)
  PE Size (KByte)       4096
  Total PE              59539
  Free PE               0
  Allocated PE          59539
  PV UUID               PjgniS-zP39-TvRu-EabS-wv1Q-Un5g-ROMg6c

  --- Physical Segments ---
  Physical extent 0 to 58788:
    Logical volume /dev/fs1/root
    Logical extents 0 to 58788
  Physical extent 58789 to 59538:
    Logical volume /dev/fs1/swap_1
    Logical extents 0 to 749


root at fs1:/etc/lvm/backup# cat fs1
# Generated by LVM2: Tue Mar 29 17:45:03 2011

contents = "Text Format Volume Group"
version = 1

description = "Created *after* executing '/sbin/vgcfgbackup'"

creation_host = "fs1" # Linux fs1 2.6.24-19-server #1 SMP Wed Aug 20
18:43:06 UTC 2008 x86_64
creation_time = 1301435103 # Tue Mar 29 17:45:03 2011

fs1 {
id = "7uN1mJ-igIG-pPaN-bpGX-bux9-uDzG-4FnyA9"
 seqno = 3
status = ["RESIZEABLE", "READ", "WRITE"]
 extent_size = 8192 # 4 Megabytes
max_lv = 0
 max_pv = 0

physical_volumes {

pv0 {
id = "PjgniS-zP39-TvRu-EabS-wv1Q-Un5g-ROMg6c"
 device = "/dev/sdc5" # Hint only

status = ["ALLOCATABLE"]
dev_size = 487749402 # 232.577 Gigabytes
 pe_start = 384
pe_count = 59539 # 232.574 Gigabytes
 }
}

logical_volumes {

 root {
id = "cIME9h-qhSB-HupF-KWVM-osd6-gVjA-xoHrQb"
 status = ["READ", "WRITE", "VISIBLE"]
segment_count = 1

segment1 {
start_extent = 0
 extent_count = 58789 # 229.645 Gigabytes

type = "striped"
stripe_count = 1 # linear

stripes = [
"pv0", 0
 ]
}
 }

swap_1 {
 id = "Gd7qqR-ns4G-NaKW-ys57-vdXs-hm7N-1vFHRf"
status = ["READ", "WRITE", "VISIBLE"]
 segment_count = 1

segment1 {
 start_extent = 0
extent_count = 750 # 2.92969 Gigabytes

type = "striped"
stripe_count = 1 # linear

stripes = [
"pv0", 58789
 ]
}
 }
}
}

root at fs1:/etc/lvm/backup# cat system
# Generated by LVM2: Tue Mar 29 17:45:03 2011

contents = "Text Format Volume Group"
version = 1

description = "Created *after* executing '/sbin/vgcfgbackup'"

creation_host = "fs1" # Linux fs1 2.6.24-19-server #1 SMP Wed Aug 20
18:43:06 UTC 2008 x86_64
creation_time = 1301435103 # Tue Mar 29 17:45:03 2011

system {
id = "VbCivG-iIUw-lPGB-6mT3-iUFd-p86P-pr7H52"
 seqno = 2
status = ["RESIZEABLE", "READ", "WRITE"]
 extent_size = 8192 # 4 Megabytes
max_lv = 0
 max_pv = 0

physical_volumes {

pv0 {
id = "N7YakG-Gi8X-0bt1-j8Uc-42GX-D8kU-RfOaR8"
 device = "/dev/sda" # Hint only

status = ["ALLOCATABLE"]
dev_size = 9223372036854775807 # 4 (null)
 pe_start = 384
pe_count = 476826 # 1.81895 Terabytes
 }
}

logical_volumes {

 home {
id = "FAnBXD-wDB7-0dbx-Hl0V-bwTu-Jace-a6pG0M"
 status = ["READ", "WRITE", "VISIBLE"]
segment_count = 1

segment1 {
start_extent = 0
 extent_count = 471860 # 1.8 Terabytes

 type = "striped"
stripe_count = 1 # linear

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



Sincerely,
Dow
________________________________________________
Dow Hurst, Research Scientist
340 Sullivan Science Bldg., Dept. of Chem. and Biochem.
University of North Carolina at Greensboro
PO Box 26170 Greensboro, NC 27402-6170
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.ale.org/pipermail/ale/attachments/20120907/af5a8956/attachment-0001.html 


More information about the Ale mailing list