I took over a fairly simple server setup with the following RAID 1 config running Ubuntu 11.10 (Kernel 3.0.0-12-server x86_64):
=> ctrl all show config
Smart Array P410i in Slot 0 (Embedded) (sn: removed)
array A (SAS, Unused Space: 1335535 MB)
logicaldrive 1 (279.4 GB, RAID 1, OK)
physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SAS, 1 TB, OK)
physicaldrive 1I:1:2 (port 1I:box 1:bay 2, SAS, 1 TB, OK)
Initially there were two 300GB disks that got replaced by 1TB disks and I now have to extend the logical volume to use that extra space.
However, when trying to do so I get the following warning:
=> ctrl slot=0 ld 1 modify size=max
Warning: Extension may not be supported on certain operating systems.
Performing extension on these operating systems can cause data to
become inaccessible. See ACU documentation for details. Continue?
(y/n)
Is it safe to say yes or am I at risk of corrupting the file system / loosing data? Rearranging and extending the file system afterwards shouldn't be an issue as I can take the server offline and boot from a gparted live disk.
Here's the config of the RAID controller in use:
=> ctrl all show detail
Smart Array P410i in Slot 0 (Embedded)
Bus Interface: PCI
Slot: 0
Serial Number: removed
RAID 6 (ADG) Status: Disabled
Controller Status: OK
Hardware Revision: Rev C
Firmware Version: 5.12
Rebuild Priority: Medium
Expand Priority: Medium
Surface Scan Delay: 15 secs
Surface Scan Mode: Idle
Wait for Cache Room: Disabled
Surface Analysis Inconsistency Notification: Disabled
Post Prompt Timeout: 0 secs
Cache Board Present: False
Drive Write Cache: Disabled
SATA NCQ Supported: True
And the partition table:
Number Start End Size Type File system Flags
1 1049kB 274GB 274GB primary ext4 boot
2 274GB 300GB 25.8GB extended
5 274GB 300GB 25.8GB logical linux-swap(v1)
Best Answer
As far as Linux is concerned it looks like the RAID array is a single device, so it is no different from migrating from a smaller single drive to a larger one. Unfortunately you are not using LVM which makes the process of using the extra space by extending
/
a little more complicated.The extension process shoudl be perfectly safe. When you next run
fdisk
or similar you'll see a chunk of unallocated space at the end of the disk.The simple way to use this space is to mount it as another filesystem: use fdisk to create /dev/sda6, create a filesystem there and mount it. What you would use the filesystem for (and so where you are best to mount it) depends on the use of your server. For a shared web hosting server you'd probably use it for
/home
, for one example of many.If you want to extend your current root partition to use the space that is a little more concoluted (if you were using LVM it would be a little easier and safer). You will need to remove the swap partition, extend the root partition, then recreate your swap. This isn't difficult to do mnaually, though unless you are confident I recomend jusing a tool like gparted (http://gparted.sourceforge.net/) instead. The manual steps would be something like:
swapoff
/etc/fstab
fdisk
remove the swap partition and the extended partition it lives inext2resize /dev/sda -v
to extend the filesystem into the new larger space. It will probably demand you runfsck
first - follow this instruction if so and then rerun.ext2resize /dev/sda -v
. Resizeing can be done live when you are exending an ext2/3/4 filesystem./etc/fstab
and useswapon
to enable itNote: I'm assuming th earray appears as /dev/sda - adjust the commands above if not of course.
Even though all the above should be safe, I strongly recommend taking a full backup and verifying that backup before proceeding (even if using tools like gparted instead of DIY).