iSCSI инициатор

iSCSI (Internet Small Computer System Interface - Малый компьютерный системный интернет интерфейс) - это протокол, который разрешает передавать SCSI команды по сети. Обычно iSCSI реализуется для сетевых дисковых массивов (Storage Area Network - SAN), чтобы позволять серверам иметь доступ к большим объемам дискового пространства. Протокол iSCSI считает клиентов инициаторами, а iSCSI сервера - целью.

Сервер Ubuntu может быть настроен как в качестве iSCSI инициатора, так и в качестве целевого объекта (сервером). Это руководство описывает команды и опции настройки по установке iSCSI инициатора. Это предполагает, что у вас есть iSCSI устройство в вашей сети и вы обладаете необходимыми правами для подключения к нему. Инструкции по установке iSCSI устройств очень сильно зависят от производителя, поэтому обратитесь к документации производителя для настройки вашего конкретного iSCSI устройства.

Для настройки сервера Ubuntu в качестве iSCSI инициатора, установите пакет open-iscsi. Введите в терминале:

sudo apt-get install open-iscsi

Once the open-iscsi package is installed, edit /etc/iscsi/iscsid.conf changing the following:

node.startup = automatic

You can check which targets are available by using the iscsiadm utility. Enter the following in a terminal:

sudo iscsiadm -m discovery -t st -p 192.168.0.10

1. m: determines the mode that iscsiadm executes in.

1. t: specifies the type of discovery.

1. p: option indicates the target IP address.

Change example 192.168.0.10 to the target IP address on your network.

If the target is available you should see output similar to the following:

192.168.0.10:3260,1 iqn.1992-05.com.emc:sl7b92030000520000-2

The iqn number and IP address above will vary depending on your hardware.

You should now be able to connect to the iSCSI target, and depending on your target setup you may have to enter user credentials. Login to the iSCSI node:

sudo iscsiadm -m node –login

Check to make sure that the new disk has been detected using dmesg:

dmesg | grep sd

[ 4.322384] sd 2:0:0:0: Attached scsi generic sg1 type 0 [ 4.322797] sd 2:0:0:0: [sda] 41943040 512-byte logical blocks: (21.4 GB/20.0 GiB) [ 4.322843] sd 2:0:0:0: [sda] Write Protect is off [ 4.322846] sd 2:0:0:0: [sda] Mode Sense: 03 00 00 00 [ 4.322896] sd 2:0:0:0: [sda] Cache data unavailable [ 4.322899] sd 2:0:0:0: [sda] Assuming drive cache: write through [ 4.323230] sd 2:0:0:0: [sda] Cache data unavailable [ 4.323233] sd 2:0:0:0: [sda] Assuming drive cache: write through [ 4.325312] sda: sda1 sda2 < sda5 > [ 4.325729] sd 2:0:0:0: [sda] Cache data unavailable [ 4.325732] sd 2:0:0:0: [sda] Assuming drive cache: write through [ 4.325735] sd 2:0:0:0: [sda] Attached SCSI disk [ 2486.941805] sd 4:0:0:3: Attached scsi generic sg3 type 0 [ 2486.952093] sd 4:0:0:3: [sdb] 1126400000 512-byte logical blocks: (576 GB/537 GiB) [ 2486.954195] sd 4:0:0:3: [sdb] Write Protect is off [ 2486.954200] sd 4:0:0:3: [sdb] Mode Sense: 8f 00 00 08 [ 2486.954692] sd 4:0:0:3: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [ 2486.960577] sdb: sdb1 [ 2486.964862] sd 4:0:0:3: [sdb] Attached SCSI disk

In the output above sdb is the new iSCSI disk. Remember this is just an example; the output you see on your screen will vary.

Next, create a partition, format the file system, and mount the new iSCSI disk. In a terminal enter:

sudo fdisk /dev/sdb n p enter w

The above commands are from inside the fdisk utility; see man fdisk for more detailed instructions. Also, the cfdisk utility is sometimes more user friendly.

Now format the file system and mount it to /srv as an example:

sudo mkfs.ext4 /dev/sdb1 sudo mount /dev/sdb1 /srv

Finally, add an entry to /etc/fstab to mount the iSCSI drive during boot:

/dev/sdb1 /srv ext4 defaults,auto,_netdev 0 0

It is a good idea to make sure everything is working as expected by rebooting the server.

Open-iSCSI Website

Debian Open-iSCSI page

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