[Starcluster] enlarge volume
Justin Riley
jtriley at MIT.EDU
Fri Aug 13 15:39:52 EDT 2010
Hi Guys,
Not sure what the issue is for you, but I just resized one of my testvolumes in 5 min like so:
1. Snapshot the volume you wish to resize
2. Create a new, larger volume based off the snapshot in step 1
3. Attach the new volume to an instance in the same zone as the new volume (on /dev/sdz for this example)
4. Login as root
5. fdisk /dev/sdz, remove the partition, recreate the partition using all cylinders
6. e2fsck -f /dev/sdz1
7. resize2fs -p /dev/sdz1
8. fdisk -l and confirm that blocks/1024 == the new volume size
8. mkdir /mnt/ebs
9. mount /dev/sdz1 /mnt/ebs
10. cd /mnt/ebs/
11. ls and see that your data is there on the new larger volume
I did this using the standard 32bit StarCluster Ubuntu 9.10 Karmic AMI.
Austin, I noticed that you're using the same echo/sfdisk command that I used inside of createvolume. I'm not sure how, if at all, this would be different from running fdisk manually given that fdisk worked for me no problems but if it works for you, great. I agree that it would be good to create an expandvolume command that creates a new larger volume automatically. The sfdisk route is the only way to do the partitioning non-interactively so this would certainly be the approach needed in expandvolume similar to createvolume. If you already have something, I'd be interested in merging the code on github assuming you do this in your fork, otherwise I will create it when I get time.
~Justin
________________________________________
From: starcluster-bounces at MIT.EDU [starcluster-bounces at MIT.EDU] On Behalf Of Austin Godber [godber at uberhip.com]
Sent: Thursday, August 12, 2010 8:31 PM
To: starcluster at mit.edu
Subject: Re: [Starcluster] enlarge volume
Alright, I have it running, here's the short version, commands only, no output, run as root, disk is attached at /dev/sdf with one partition:
Check the filesystem (might want to use -f to force a real check)
# fsck /dev/sdf1
Repartition with sfdisk, start at the first cylinder end at the last
# echo ",,L" | sfdisk /dev/sdf
Resize the ext3 filesystem
# resize2fs /dev/sdf1
Recheck the filesystem
# fsck -f /dev/sdf1
Now mount and check that the data is there and the size is correct with df -h.
Let me know if it works for you.
- Austin
Here is my verbose version, with output.
# fsck /dev/sdf1
fsck from util-linux-ng 2.16
e2fsck 1.41.9 (22-Aug-2009)
/dev/sdf1: clean, 11/196608 files, 29901/785176 blocks
# sfdisk -l /dev/sdf
Disk /dev/sdf: 652 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sdf1 0+ 390 391- 3140707 83 Linux
/dev/sdf2 0 - 0 0 0 Empty
/dev/sdf3 0 - 0 0 0 Empty
/dev/sdf4 0 - 0 0 0 Empty
# echo ",,L" | sfdisk /dev/sdf
Checking that no-one is using this disk right now ...
OK
Disk /dev/sdf: 652 cylinders, 255 heads, 63 sectors/track
Old situation:
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sdf1 0+ 390 391- 3140707 83 Linux
/dev/sdf2 0 - 0 0 0 Empty
/dev/sdf3 0 - 0 0 0 Empty
/dev/sdf4 0 - 0 0 0 Empty
New situation:
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0
Device Boot Start End #cyls #blocks Id System
/dev/sdf1 0+ 651 652- 5237189+ 83 Linux
/dev/sdf2 0 - 0 0 0 Empty
/dev/sdf3 0 - 0 0 0 Empty
/dev/sdf4 0 - 0 0 0 Empty
Warning: no primary partition is marked bootable (active)
This does not matter for LILO, but the DOS MBR will not boot this disk.
Successfully wrote the new partition table
Re-reading the partition table ...
If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)
to zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1
(See fdisk(8).)
# resize2fs /dev/sdf1
resize2fs 1.41.9 (22-Aug-2009)
Resizing the filesystem on /dev/sdf1 to 1309297 (4k) blocks.
The filesystem on /dev/sdf1 is now 1309297 blocks long.
# fsck -f /dev/sdf1
fsck from util-linux-ng 2.16
e2fsck 1.41.9 (22-Aug-2009)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/sdf1: 11/327680 files (0.0% non-contiguous), 38511/1309297 blocks
On 08/12/2010 08:01 PM, Dan Yamins wrote:
Let me add one more thing to this thread:
Even on ubuntu, even with my original volume, you can't do "e2fsck" of the "device" , e.g.
$ e2fsck /dev/sdz
Couldn't find ext2 superblock, trying backup blocks...
e2fsck: Bad magic number in super-block while trying to open /dev/sdo
...
Is that to be expected? In a number of tutorials on resizing EBS volumes, i have seen this done with the devices itself. Is the reason this is failing because its a partitioned drive?
On Thu, Aug 12, 2010 at 6:43 PM, Dan Yamins <dyamins at gmail.com<mailto:dyamins at gmail.com>> wrote:
Do you have a snapshot? I have used parted and e2resizefs to expand an ext3 filesystem without trouble.
So I'm trying parted on a new, clean volume created from the snapshot, attached to /dev/sdm As I explained before, I can't do
$ parted /dev/sdm
[root at domU-12-31-39-0E-B2-61 ~]# parted /dev/sdm
Error: Error initialising SCSI device /dev/sdm - Invalid argument
AUstin, when you did this did you get that same error?
I CAN do parted on the path:
$ parted /dev/sdm1
GNU Parted 1.8.1
Using /dev/sdm1
Welcome to GNU Parted! Type 'help' to view a list of commands.
But then i get this error:
(parted) resize 1 0 500GB
Error: The location 500GB is outside of the device /dev/sdo1.
Which is course is true ...
(parted) print
Disk /dev/sdm1: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Number Start End Size File system Flags
1 0.00kB 21.5GB 21.5GB ext3
So I'm not sure where to go from here...
Dan
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