I have created a DBaaS instance three weeks ago, and now it was time to attach new storage in the Oracle Compute Cloud Service to have additional disk space for some Trivadis tools. But after a reboot with a mouse-click in the DBaaS Cloud Service Console, the disk was lost and had to be re-attached.
The procedure to add additional storage is documented in this Oracle tutorial: http://www.oracle.com/webfolder/technetwork/tutorials/obe/cloud/dbaas/OU/IntroDBaaS/AddStorageDBaaSInstance/AddStorageDBaaSInstance.html
Creating additional Storage in the Oracle Compute Cloud Service
In the Create Storage Volume menu, I have created a new storage volume of 10GB and attached it to my running DBaaS instance called TrivadisExPerf.
OS Verfication
After some minutes waiting, I logged in on the database server to verify the operation. The disk was attached as device xvdg.
-bash-4.1# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT xvdb 202:16 0 21G 0 disk ├─xvdb1 202:17 0 200M 0 part /boot ├─xvdb2 202:18 0 15.8G 0 part / └─xvdb3 202:19 0 4G 0 part [SWAP] xvdc 202:32 0 30G 0 disk └─xvdc1 202:33 0 30G 0 part /u01 xvdd 202:48 0 42G 0 disk └─xvdd1 202:49 0 42G 0 part └─fraVolGroup-lvol0 (dm-2) 252:2 0 42G 0 lvm /u03 xvde 202:64 0 10G 0 disk └─xvde1 202:65 0 10G 0 part └─redoVolGroup-lvol0 (dm-1) 252:1 0 10G 0 lvm /u04 xvdf 202:80 0 25G 0 disk └─xvdf1 202:81 0 25G 0 part └─dataVolGroup-lvol0 (dm-0) 252:0 0 25G 0 lvm /u02 xvdg 202:96 0 10G 0 disk
Creating a Filesystem
Then I created a new partition with fdisk, formatted the partion as Ext4 and mounted it as /u05. At this point, I did not add something to /etc/fstab. But this had no impact for later actions.
-bash-4.1# df -m
Filesystem 1M-blocks Used Available Use% Mounted on
/dev/xvdb2 15931 8235 6887 55% /
tmpfs 7538 3945 3593 53% /dev/shm
/dev/xvdb1 194 91 94 49% /boot
/dev/xvdc1 30237 10755 17947 38% /u01
/dev/mapper/dataVolGroup-lvol0
25195 11697 12218 49% /u02
/dev/mapper/fraVolGroup-lvol0
42330 22682 17498 57% /u03
/dev/mapper/redoVolGroup-lvol0
10076 3223 6341 34% /u04
/dev/xvdg1 10077 151 9414 2% /u05
Restart via DBaaS Cloud Service Console
The DBaaS restart was executed by the Service Console. In the background the DBaaS service was restarted automatically. The process is visible in the console and you can see the progress. I don’t know why Oracle requires more than 10 minutes for a simple restart, in some cases more than 20 minutes…
The Storage is lost…
After the restart I logged in again in the terminal. And what do I see? The storage was no more attached at the instance. There was no /dev/xdg or /dev/xdg1 visible.
-bash-4.1# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT xvdb 202:16 0 21G 0 disk ├─xvdb1 202:17 0 200M 0 part /boot ├─xvdb2 202:18 0 15.8G 0 part / └─xvdb3 202:19 0 4G 0 part [SWAP] xvdc 202:32 0 30G 0 disk └─xvdc1 202:33 0 30G 0 part /u01 xvdd 202:48 0 42G 0 disk └─xvdd1 202:49 0 42G 0 part └─fraVolGroup-lvol0 (dm-2) 252:2 0 42G 0 lvm /u03 xvde 202:64 0 10G 0 disk └─xvde1 202:65 0 10G 0 part └─redoVolGroup-lvol0 (dm-1) 252:1 0 10G 0 lvm /u04 xvdf 202:80 0 25G 0 disk └─xvdf1 202:81 0 25G 0 part └─dataVolGroup-lvol0 (dm-0) 252:0 0 25G 0 lvm /u02
After re-attaching the storage to the instance in the Oracle Compute Cloud Storage menu, the storage was back again. And I tried another way to restart a server…
Restart in the Terminal
First I checked again if the storage was attached. The device /dev/xdg was here.
-bash-4.1# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT xvdb 202:16 0 21G 0 disk ├─xvdb1 202:17 0 200M 0 part /boot ├─xvdb2 202:18 0 15.8G 0 part / └─xvdb3 202:19 0 4G 0 part [SWAP] xvdc 202:32 0 30G 0 disk └─xvdc1 202:33 0 30G 0 part /u01 xvdd 202:48 0 42G 0 disk └─xvdd1 202:49 0 42G 0 part └─fraVolGroup-lvol0 (dm-2) 252:2 0 42G 0 lvm /u03 xvde 202:64 0 10G 0 disk └─xvde1 202:65 0 10G 0 part └─redoVolGroup-lvol0 (dm-1) 252:1 0 10G 0 lvm /u04 xvdf 202:80 0 25G 0 disk └─xvdf1 202:81 0 25G 0 part └─dataVolGroup-lvol0 (dm-0) 252:0 0 25G 0 lvm /u02 xvdg 202:96 0 10G 0 disk └─xvdg1 202:97 0 10G 0 part
Then I restarted the server with the shutdown command.
-bash-4.1# shutdown -r now Broadcast message from opc@TrivadisExPerf (/dev/pts/0) at 20:48 ... The system is going down for reboot NOW!
And after the restart, the storage was still here. The device /dev/xdg was available. And it didn’t require 10 mins, after 2 mins the server was back again and ready to log-in.
-bash-4.1# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT xvdb 202:16 0 21G 0 disk ├─xvdb1 202:17 0 200M 0 part /boot ├─xvdb2 202:18 0 15.8G 0 part / └─xvdb3 202:19 0 4G 0 part [SWAP] xvdc 202:32 0 30G 0 disk └─xvdc1 202:33 0 30G 0 part /u01 xvdd 202:48 0 42G 0 disk └─xvdd1 202:49 0 42G 0 part └─fraVolGroup-lvol0 (dm-2) 252:2 0 42G 0 lvm /u03 xvde 202:64 0 10G 0 disk └─xvde1 202:65 0 10G 0 part └─redoVolGroup-lvol0 (dm-1) 252:1 0 10G 0 lvm /u04 xvdf 202:80 0 25G 0 disk └─xvdf1 202:81 0 25G 0 part └─dataVolGroup-lvol0 (dm-0) 252:0 0 25G 0 lvm /u02 xvdg 202:96 0 10G 0 disk └─xvdg1 202:97 0 10G 0 part
Summary
If you want to attach additional storage via Oracle Compute Cloud Service, it’s better at the moment NOT to restart your DBasS service instance via the console. Just use the good old shutdown command. I am sure, this can not be a feature, this is must be a bug.
Additional Information
When you attach a disk with the Scale Up function, then it works properly.
Now you have two ways how to attach additonal storage which are working. It’s like in the movie Indiana Jones and the Last Crusade:
You must choose. But choose wisely…