napp-it: iSCSI LUN

[philip49]

If I want a simular setup of Nexentastor for iSCSI: what do I have to do?

• I need a view (otherwise I can't use it for iSCSI)
• I need the possibility for a auto-snap job
• It must be thinly provisioned
• Compression is desirable
• Possibility to choose blocksize
• Perhaps a mountpoint under a global directory (/volumes)

With

• with Comstar Thin prov Lu --> no auto-snap job possible
• with comstar Volume --> no view possible
• with zfs-filesystem and a Thin prov LU in this filesystem--> OK?
• with Volume and then a comstar Volume-LU --> OK?

What is the best solution? How do I enable compression? Is it possible to mount under /volumes?

Philip

 

[Magnus919]

I'm not a nexenta user but if you can drop to command line on these things, as I suspect you can, turning on compression on any zfs filesystem is dead nuts easy. Two steps.

• zpool set feature@lz4_compress=enabled <poolname>
  
• zfs set compression=lz4 <dataset>

If they are using an ancient version of illumos without feature flag enabled zpool, you'll have to fall back to lzjb compression:

• zfs set compression=lzjb <dataset>

 

[gea]

Comstar works like
- create a logical unit, this can be a file, a zvol or a raw disk
- create a target
- create a target group with targets as members
- create a view from a logical unit to a target group to make the LUN visible in the targets

now I do not understand your intention
- do it on NexentaStor
- do it on napp-it

create an initiator + pool instead a target

relating zvols
A zvol is a ZFS filesystem used like a blockdevice
A volume in Nexenta speech is the same as pool in the ZFS world
Nexenta mounts all pools below /volumes per default. All others mount a pool under / per default.

 

[philip49]

I want to do it on napp-it. I need a block device (zvol) with the ability to use it with iscsi (so I need a view). I also need a auto-snap job (per zvol).
With Comstar in the napp-it menu you have:

• a Comstar Volume
• a Comstar Thin Prov LU
• a Comstar Raw LU
• a Comstar Volume LU

Which one should I use to have a view and an auto-snap job?

Philip

Comstar works like
- create a logical unit, this can be a file, a zvol or a raw disk
- create a target
- create a target group with targets as members
- create a view from a logical unit to a target group to make the LUN visible in the targets

now I do not understand your intention
- do it on NexentaStor
- do it on napp-it

create an initiator + pool instead a target

relating zvols
A zvol is a ZFS filesystem used like a blockdevice
A volume in Nexenta speech is the same as pool in the ZFS world
Nexenta mounts all pools below /volumes per default. All others mount a pool under / per default.

 

[gea]

I want to do it on napp-it. I need a block device (zvol) with the ability to use it with iscsi (so I need a view). I also need a auto-snap job (per zvol).
With Comstar in the napp-it menu you have:

• a Comstar Volume
• a Comstar Thin Prov LU
• a Comstar Raw LU
• a Comstar Volume LU

Which one should I use to have a view and an auto-snap job?

Philip

You have two options:

1. simple setting
- use menu ZFS filesystems and enable iSCSI for a filesystem
This creates a zvol under the filesystem as a logical unit, a target, a target group and a view in a 1:1 relation

2. advanced setting
- use menu Comstar >> volume to create a zvol
- use menu Comstar >> Logical Units >> create volume LU ( use the zvol that you created in the line above)
then create a target, a target group and a view from the logical unit -> target group

3.
- set an autosnap job on this zvol (its a ZFS filesystem) in menu jobs >> autosnap >> create
ex. If you create a zvol "zvol1" under /tank/data (a regular ZFS) you can autosnap /tank/data/zvol1.
You can also replicate this zvol and re-import.

- if you need compress, enable lz4 on the parent filesystem

 

[philip49]

1. I can't find this one. I can create a ZFS filesystem but how do I enable iSCSI on it. I can make a zvol under this filesystem but that isn't what you proposed.

2. works perfect and I understand this

3. also OK

What is your choice?

• filesystem with a zvol under it
• create volume LU under a Comstar volume

Thanks

Philip

You have two options:

1. simple setting
- use menu ZFS filesystems and enable iSCSI for a filesystem
This creates a zvol under the filesystem as a logical unit, a target, a target group and a view in a 1:1 relation

2. advanced setting
- use menu Comstar >> volume to create a zvol
- use menu Comstar >> Logical Units >> create volume LU ( use the zvol that you created in the line above)
then create a target, a target group and a view from the logical unit -> target group

3.
- set an autosnap job on this zvol (its a ZFS filesystem) in menu jobs >> autosnap >> create
ex. If you create a zvol "zvol1" under /tank/data (a regular ZFS) you can autosnap /tank/data/zvol1.
You can also replicate this zvol and re-import.

- if you need compress, enable lz4 on the parent filesystem

 

[gea]

1. I can't find this one. I can create a ZFS filesystem but how do I enable iSCSI on it. I can make a zvol under this filesystem but that isn't what you proposed.

Enable iSCSI (simple way)
click in the row of a filesystem under FC/IB/iSCSI on "zfs unset" to enable iSCSI sharing

What is your choice?

• filesystem with a zvol under it
• create volume LU under a Comstar volume

There is nothing like a Comstar volume!

Comstar is a framework to manage iSCSI/FC targets.
A volume is a ZFS pool in Nexenta Speech.
A LU (logical unit) is a blockdevice like a raw disk or a file or a ZFS filesystem (zvol) that is used like a disk


So your options are
- create a LU on a zvol or on a file (raw disk is pointless due to missing redundancy)

 

[philip49]

I found to enable iSCSI on a filesystem (just click on the 'ZFS Filesystem' top-menu). I didn't know there was also an action on this. I definitely need a good manual :-(

About the 2 possibilities, I try to formulate it better.
What do you suggest as the best practise;

• a filesystem with a zvol under it, with enabled iSCSI
  
• - use menu Comstar >> volume to create a zvol
  - use menu Comstar >> Logical Units >> create volume LU ( use the zvol that you created in the line above)

Thanks for the quick answers. I try to find my way in napp-it after using Nexenta-GUI and CLI-commands.

Philip

Enable iSCSI (simple way)
click in the row if a filesystem under iSCSI on "zfs unset" to setup iSCSI sharing


There is nothing like a Comstar volume!

Comstar is a framework to manage iSCSI/FC targets.
A volume is a ZFS pool in Nexenta Speech.
A LU (logical unit) is a blockdevice like a raw disk or a file or a ZFS filesystem that is used like a disk


So your options are
- built a LU on a zvol or on a file

 

[gea]

I found to enable iSCSI on a filesystem (just click on the 'ZFS Filesystem' top-menu). I didn't know there was also an action on this. I definitely need a good manual :-(

About the 2 possibilities, I try to formulate it better.
What do you suggest as the best practise;

• a filesystem with a zvol under it, with enabled iSCSI
  
• - use menu Comstar >> volume to create a zvol
  - use menu Comstar >> Logical Units >> create volume LU ( use the zvol that you created in the line above)

Thanks for the quick answers. I try to find my way in napp-it after using Nexenta-GUI and CLI-commands.

Philip

Whether you share a ZFS filesystem via menu ZFS filesystems in a easy to setup way (basically on/off)
or use the Comstar menu does not matter, it is the same.

In the first case, you create a zvol, a LU, a target, a target group and a view in a 1:1 relation.
If you only need some targets, this is the easiest way. You could do the same via menue comstar manually.

The advantage of the Comstar menu:
You can do complex settings ex combine LUs, targets and target groups and views to
- make several LUs visible in one target (multiple LUNs per target)
- combine settings with target groups (views are related to target groups with targets as members)
- restrict access via host groups

Manual setup via Comstar menu is the way for large and complex enterprise settings.

about manual:
I am currently working on updates on my basic manual
http://www.napp-it.org/doc/downloads/napp-it.pdf

 

[philip49]

Thanks for all the effort

Philip

Whether you share a ZFS filesystem via menu ZFS filesystems in a easy to setup way (basically on/off)
or use the Comstar menu does not matter, it is the same.

In the first case, you create a zvol, a LU, a target, a target group and a view in a 1:1 relation.
If you only need some targets, this is the easiest ways. You could do the same via menue comstar manually.

The advantage of the Comstar menu:
You can do complex settings ex combine LUs, targets and target groups and views to
- make several LUs visible in one target (multiple LUNs per target)
- combine settings with target groups (views are related to target groups with targets as members)
- restrict access via host groups

Manual setup via Comstar menu is the way for large and complex enterprise settings.

about manual:
I am currently working on updates on my basic manual
http://www.napp-it.org/doc/downloads/napp-it.pdf