Hardware Raid Expansion and LVM

[Seann Clark]

Roberto Ragusa wrote:
> Seann Clark wrote:
>   
>>    I am looking for a little help on finding out the best way to do
>> this. I had a 4 disk 1.4TB RAID 5 array, and extended that to an 8 disk
>> 3.18TB array, on a 64 bit system.The Raid card handled the migration of
>> the disks well, and everything on that side is up and running as it
>> should. Problem is I don't know how to extend LVM to a larger size,
>> without doing the whole adding of physical drives, and so forth, and the
>> pv display doesn't show more than the 1.4TB that I started with. Most
>> documentation details software RAID procedures that don't really work
>> with this. I figure I am doing something(lots of things) wrong.
>>     
>
> Have a look at the thread called "lvm resizing and shifting" (23/8/2008).
> The issue is similar and my proposal worked in that case.
> Your problem is that you have a 3TB disk (sdb) containing just
> a 1.4TB partition (sdb1, which is your pv).
>   
I will check out that thread, that should be pretty interesting of a 
read, I had to have missed it when I was reviewing the list email.
> I obviously have to recommend to be very careful when doing these
> operations. You have a backup of your data, right?
>   
I don't have a backup for this server right now, so I will be getting 
that ready to start working (I hope) on this system. My problem is that 
I have 1.2TB of this filled.
> I'm also a bit concerned about the fact that you will break the 2TB
> per partition barrier; I don't know if that limit has been totally
> removed nowadays.
>
>   
Is the 2TB issue still in place for ext3 filesystems in 64bit? I am not 
sure, I don't really see mention of this so I might have missed it. If 
that is the case, I will just set my controller to autocarve and set up 
two partitions for this.It shouldn't be a problem with the hardware RAID
> Alternatively, you can add a sdb2 and then pvcreate, vgextend, lvextend.
>
>   
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] 20971519 512-byte
>> hardware sectors (10737 MB)
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] Write Protect is off
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] Write cache: enabled,
>> read cache: disabled, doesn't support DPO or FUA
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] 20971519 512-byte
>> hardware sectors (10737 MB)
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] Write Protect is off
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] Write cache: enabled,
>> read cache: disabled, doesn't support DPO or FUA
>> Oct  9 11:58:39 haruhi kernel: sda: sda1 sda2
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:0: [sda] Attached SCSI disk
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] Very big device. Trying
>> to use READ CAPACITY(16).
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] 6814820353 512-byte
>> hardware sectors (3489188 MB)
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] Write Protect is off
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] Write cache: enabled,
>> read cache: disabled, doesn't support DPO or FUA
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] Very big device. Trying
>> to use READ CAPACITY(16).
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] 6814820353 512-byte
>> hardware sectors (3489188 MB)
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] Write Protect is off
>> Oct  9 11:58:39 haruhi kernel: sd 0:0:0:1: [sdb] Write cache: enabled,
>> read cache: disabled, doesn't support DPO or FUA
>>     
>
> The important information is just the line you have not included
> (sdb: sdb1, sdb2?).
> What about /proc/partitions?
The drive in question is sdb(1)
What is in /proc/partitions:

major minor  #blocks  name

   8     0   10485759 sda
   8     1     200781 sda1
   8     2   10281600 sda2
   8    16 3407410176 sdb
   8    17 1454324256 sdb1
 253     0 1462468608 dm-0
 253     1    2031616 dm-1