[Question]: Use iSCSI for HDD pass-through ?

[srctar]

Question

from case https://github.com/vdsm/virtual-dsm/issues/651:

• If a disk were moved from a vDSM to a physical DSM, the physical DSM will let you confirm to format it.
• If a disk were moved from a physical DSM to a vDSM, the vDSM will not recognize the disk.
• It is avaliable to move the disks among only vDSMs or only physical DSMs.

since vDSM running on a docker, why not build an iSCSI Server on the physical machine?

then vDSM use iSCSI Client, connect to the HDD,
No HDD should be format

[kroese]

I am not sure what your question is? Yes, you can use iSCSI LUN if you install the SAN Manager package from the Package Center.

The reason not many people do that its because its not easy to setup your own iSCSI server on the physical host. So that is why mounting a disk image is a much easier solution for most users.

[srctar]

I am not sure what your question is? Yes, you can use iSCSI LUN if you install the SAN Manager package from the Package Center.

The reason not many people do that its because its not easy to setup your own iSCSI server on the physical host. So that is why mounting a disk image is a much easier solution for most users.

When someone has an DSM login disk, all data on it. they want to use vDSM, should format the physical disk.

by using iSCSI, formating is not needed, sharing the disk(with data), then the vDSM can use it without any change.

I`ll try this way, and report is it works good

[kroese]

Okay, thanks for reporting!

[srctar]

Okay, thanks for reporting!

Yesterday I asked synology customer helpe, the service man tell me there is no iSCSI Clinet on DSM, and leavve a feature to add iSCSI Clinet on the next VERSION.

When I give up , I found a serve names /usr/syno/etc.defaults/rc.iscsi, and when exec /usr/syno/etc.defaults/rc.iscsi start, a iscsiadm show on my DSM shell. then:

• iscsiadm -m discovery -t sendtargets -p my-physical-machine-ip 3260
• iscsiadm -m node -T iqn.xxx.Target-xxx -p my-physical-machine-ip --login
• fdisk /dev/iscsi1
• mkfs.ext4 /dev/iscsi1
• mount /dev/iscsi1 /volume2 SO :

  # df -h
  Filesystem                        Size  Used Avail Use% Mounted on
  /dev/md0                          7.9G  4.0G  3.8G  51% /
  /dev/iscsi1                       984G   77M  984G   1% /volume2

it works very good, and all the file on my old DSM disk can be shared with docker DSM.

[kroese]

Very impressive that you got this working! Even the Synology employees did not know that it was possible haha!

[srctar]

Very impressive that you got this working! Even the Synology employees did not know that it was possible haha!

I think they don`t want users do this， just like what they show on ssh。 Other way , synology knowledge say BTRFS and EXT4 can not be Shrinkage， but I tried， it ok to Shrinkage