Iscsi

Links

• http://nil.uniza.sk/linux-howto/linux-mint-mouting-freenas-iscsi-disk
• iscsiadm command examples
• Scsi-target-utils Quickstart Guide
• Creating and managing iSCSI targets
• https://wiki.archlinux.org/index.php/TGT_iSCSI_Target
• iSCSI on ESXCLI
• https://wiki.archlinux.org/index.php/ISCSI/tgt
• https://ask.openstack.org/en/question/30299/how-to-resize-an-instance-residing-on-a-block-storage-volume/
• targetcli
• https://www.truenas.com/community/resources/why-iscsi-often-requires-more-resources-for-the-same-result.41/

Implementations

Features comparison between Linux SCSI targets

IET

iSCSI Enterprise Target

• ietd
• ietadm
• iscsitarget
• iscsid

LIO

• targetcli

SCST

iSCSI Target Driver

• scst

STGT

Predecessor of LIO

ISTGT

iSCSI Target

FreeBSD/Linux

• istgtcontrol and friends

Comstar

Commands:

• itadm
• stmfadm

TGT

Linux iSCSI Target

• tgtd
• tgdadm

open-iscsi

• iscsiadm?

And there's tgt

FAQ

On ISCSI client

Find targets

iscsi_discovery 192.168.100.32
    

Please logout from all targets on 192.168.178.3:3260 before trying to run discovery on that portal

??

List connected targets

iscsiadm -m session -P 3

which seems to list only one, for multiple:

tgtadm --lld iscsi --op show --mode conn --tid 1

but that needs more work

List targets

iscsiadm -m discovery -t sendtargets -p 192.168.100.32

Connect to target

iscsiadm -m node --targetname="iqn.2018-5.mynet:drbd0" --portal "192.168.100.32" --login

if you get things like "iscsiadm: No records found" try a thing like

iscsiadm --mode node -l all

iscsiadm: Could not log into all portals:

Disconnect from target

iscsiadm -m node -T iqn.2018-5.mynet:drbd0 -p 192.168.100.32 -u

 

Show session id

iscsiadm -m session -P 1

 

Rescan ??

iscsiadm -m node --targetname="foo.bar" -R

Disconnect all targets

iscsiadm --mode node -u all

Rescan session

iscsiadm -m session -r SID --rescan⁠

iscsiadm: Could not log into all portals

??

On server

list targets

tgtadm --lld iscsi --mode target --op show

list connected targets

To list all connections to target with id 1:

tgtadm --lld iscsi --mode conn --op show --tid 1

And disconnect target:

tgtadm --lld iscsi --op delete --mode conn --tid 1 --sid 2 --cid 0

Create iscsi target and Lun

tgtadm --lld iscsi --mode target --op new --tid=1 --targetname iqn.2009-02.com.example:for.all
tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 1 -b /var/tmp/iscsi-disk1

Delete iscsi target and Lun

tgtadm --lld iscsi --mode logicalunit --op delete --tid 1 --lun 1
tgtadm --lld iscsi --mode target --op delete --tid=1

Reload tgtd configuration

tgt-admin --update ALL

or

tgt-admin --update your.irqn.string

Show tgdt config

tgt-admin --dump

Grow/resize target

After resizing the target (lvresize or whatever)

tgt-admin --update tid=xx -v -f

Show targets

tgt-admin -s

Show target config

This includes target parameters

tgtadm --lld iscsi -o show -m target --tid=1

The disk contains an unclean file system (0, 0).

Metadata kept in Windows cache, refused to mount.
Falling back to read-only mount because the NTFS partition is in an
unsafe state. Please resume and shutdown Windows fully (no hibernation
or fast restarting.)

ntfsfix /dev/sdc1

On ESXi

esxcli storage core path list
storage core adapter rescan --adapter=vmhba
esxcli iscsi adapter discovery rediscover --adapter vmhba64
esxcli iscsi adapter param get -A vmhba64

Error messages

connection1:0: detected conn error (1020)

These messages are seen when an iSCSI connection times out (1011 means timeout on initiator side and 1020 means the target dropped the connection)

tgtadm: failed to send request hdr to tgt daemon, Transport endpoint is not connected

tgtd not running :)

 

tgtd: iser_ib_init(3436) Failed to initialize RDMA; load kernel modules?

comment out default-driver

 

iscsiadm: No portals found

ACL issue, try something like

tgtadm --lld iscsi --op bind --mode target --tid 6 -I ALL

 

iscsiadm: No records found

Try

iscsiadm -m discovery -t sendtargets -p <ip-address>