Until a better naming convention is implemented, here is what one might do to get around this. Also, it appears that the device is not renamed to the xvd naming convention automatically. For example, it seems that volumes mounted pre-boot do not have the /dev/ prefix in the vendor info, while volumes mounted after have the /dev/ prefix. One thing I've noticed (and has been mentioned elsewhere) is that the device name in the vendor-specific name is different depending on when and how the volume is mounted. I've copied the current udev rules and scripts from the Amazon Linux AMI here: I can't seem to find the python script publicly, but it's available on the Amazon Linux AMI and is licensed under the Apache 2.0 license. I realize python is not installed on CoreOS, but the script could be rewritten to provide the basic functionality needed for udev renaming.Īn example udev rule without using the python script can be found here: AWS Linux handles this with the help of a python script named ebsnvme-id that read EBS information from the NVMe device. This would allow systemd mounts to work across all EC2 instance types without special hacks or relying on fixed device names. It would be great if CoreOS could provide similar rules. This keeps things consistent with the older naming rules and matches what is configured in EBS block device mappings provided when launching the instance. AWS Linux provides built-in udev rules that symlink the NVMe devices to their equivalent /dev/sd naming. With the newer m5 and c5 instances, EBS volumes show up as NVMe devices. You have another approach.AWS CoreOS 1688.5.3 HVM on m5.* or c5.* instances Desired FeatureĪdd udev symlink rules to map NVMe devices to traditional xvd device names. Sometimes RDM disks are assigned to guests from VMware in that case above method is not sufficient to identify disks. The LUN displayed here correlate to the LUNs that you looked up in the Guest using lsscsi, or. The LUN of the disk will be displayed in the disk detail pane. Select a data disk from the list of attached disks. 0:0 is matching that means disk sda in Linux is what we are looking at in VMware Hard Disk 1. In the Azure portal, select 'Virtual Machines' to display a list of your Virtual Machines. Now match this SCSI id with the id you got from VMware console (VM settings panel). Sometimes you have to check first and third fields to match numbers. We are interested here in channel and id numbers.įor example, disk sda in the above output has numbers 0:0:0:0 whereas disk sdb has 0:0:1:0. Every disk has 4 numbers displayed in the output. This will show us disk names along with 4 numbers. We are filtering disk messages from syslog at the boot, to get disk SCSI id identified by the kernel. In vmware :Ĭheck VM settings and identify disk SCSI id.Īttached scsi disk sda at scsi0, channel 0, id 0, lun 0Īttached scsi disk sdb at scsi0, channel 0, id 1, lun 0 To map VMware disks to Linux VM, we need to check and relate the SCSI id of disks. Since VMware, Linux is not a single vendor configuration, I think it’s not yet possible to get things done with single-line command. This makes it possible to integrate tasks into a single command. The block device driver for the instance assigns the actual volume name when mounting the volume, and the name assigned can be different from the name that Amazon EC2 uses. Follow the steps below to find the mapping between the two and vice versa. The /dev/mapper/mpathY is the multipath'd device where as the /dev/sdX is the actual device underlying it. In HP, both hardware (server), OS software (HPUX), and virtualization technology (iVM) all three products are owned/developed by HP. When you attach a volume to your instance, you include a device name for the volume. Sometimes, to troubleshoot some multipath related issues, you would require to map the /dev/mapper/mpathY device to its corresponding /dev/sdX device. Like HPUX, we do not have a direct command to see the mapping of disks. In this post, we will be seeing how to map Linux disk to VMware disk (VMware virtualization). In other posts, we already explained mapping iVM disks to host disks in HPUX (HPUX virtualization). Any activity related to physical attribute which is to be done on guest machine seeks perfect mapping of hardware from guest to host. Since disk or hardware is attached to the Host physically and made visible to the guest server. It’s always a challenge to identify the correct disk physically when it’s being used in the virtualization layer.
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