# iSCSI and multipath on CentOS 7 ##### 系統環境 - iSCSI Storage: NetApp FAS8200 - Linux OS: CentOS 7 - Server H/W: HP DL380 Gen10 - iSCSI 用網路卡: 10G SFP 光纖網路卡 x 2 ##### 設定網路卡 使用指令 nmtui 分別設定兩張網卡的 IP 與 Mask > 注意: 這兩張網卡不要作 Bonding。 ##### 設定 iSCSI 安裝 iscsi 套件 ```shell yum install iscsi-initiator-utils ``` 設定 iscsid.conf: `/etc/iscsi/iscsid.conf` ``` # 調整 timeout #node.session.timeo.replacement_timeout = 120 node.session.timeo.replacement_timeout = 5 # 調整 node 自動 Login node.startup = automatic ``` 設定 initiator name: `/etc/iscsi/initiatorname.iscsi` 命名規則可以參考 - iqn.<year-to-date>.<your-domain>.<your-hostname>:redhat-disk 例如 InitiatorName=iqn.2019-02.mycompany.bdb7-a:redhat-disk - initiator name 必須與 Storage 端的設定相同 - 不同的 Host 之間的名稱不能相同 ##### 安裝 multipath 與 netapp\_linux\_unified\_host\_utilities ``` yum install device-mapper-multipath yum install libhbaapi rpm -ivh netapp_linux_unified_host_utilities-7-1.x86_64.rpm ``` > 如果沒有安裝 libhbaapi，執行 sanlun 會出現錯誤。 ##### 連接 iSCSI storage 新增網卡裝置 ``` iscsiadm -m iface -I iscsi_ens2f0 --op=new iscsiadm -m iface -I iscsi_ens3f0 --op=new ``` Discovery for the storage ``` iscsiadm -m discovery -t sendtargets -p :3260 ``` > 如果 NetApp storage 有設置多個 iSCSI IPs，只需要對其中一個 IP 作偵測，輸出結果就會顯示所有 IP。 ``` [root@bdb7-b RPMs]# iscsiadm -m discovery -t sendtargets -p 10.18.104.32:3260 10.18.104.32:3260,1038 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.34:3260,1040 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.33:3260,1039 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.31:3260,1037 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.32:3260,1038 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.34:3260,1040 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.33:3260,1039 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 10.18.104.31:3260,1037 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 ``` Login nodes ``` iscsiadm -m node -l all ``` > 輸出結果會顯示多行如下資訊 ``` [root@bdb7-b RPMs]# iscsiadm -m node -l all Logging in to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.32,3260] (multiple) Logging in to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.32,3260] (multiple) Logging in to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.34,3260] (multiple) Logging in to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.34,3260] (multiple) Logging in to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.33,3260] (multiple) Logging in to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.33,3260] (multiple) Logging in to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.31,3260] (multiple) Logging in to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.31,3260] (multiple) Login to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.32,3260] successful. Login to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.32,3260] successful. Login to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.34,3260] successful. Login to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.34,3260] successful. Login to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.33,3260] successful. Login to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.33,3260] successful. Login to [iface: iscsi_ens2f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.31,3260] successful. Login to [iface: iscsi_ens3f0, target: iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16, portal: 10.18.104.31,3260] successful. ``` 使用 sanlun 確認 LUN Disks ``` [root@bdb7-b RPMs]# sanlun lun show controller(7mode/E-Series)/ device host lun vserver(cDOT/FlashRay) lun-pathname filename adapter protocol size product --------------------------------------------------------------------------------------------------------------- TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdag host19 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdaf host20 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdae host17 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdad host18 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdac host16 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdab host15 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_3_vol/BDB7_B_3 /dev/sdz host20 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_3_vol/BDB7_B_3 /dev/sdaa host19 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdy host14 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_3_vol/BDB7_B_3 /dev/sdx host18 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_3_vol/BDB7_B_3 /dev/sdw host17 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_3_vol/BDB7_B_3 /dev/sdt host16 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_3_vol/BDB7_B_3 /dev/sdu host15 iSCSI 500.1g cDOT ... ``` ##### 設定 multipath 初始化後會自動產生設定檔 multipath.conf ``` mpathconf --enable --with_multipathd y ``` 建立 device alias name 與 LUN WWID 的對應 >
注意：在 RedHat 7.6 的 multipathd 預設雖然已設定 user_friendly_names yes
但對於 NetApp 的 LUN disks 仍不會自動建立 mpath X 的磁碟名稱，而只會顯示 WWID，詳細原因請見附檔。
為了爾後方便管理，必須手動建立磁碟名稱與 WWID 對應。
編輯 /etc/multipath.conf , 在檔案最下方新增以下幾行 ``` ... multipaths { multipath { wwid 3600a0980383136312d3f4e387455564b alias mpath1 } multipath { wwid 3600a0980383136312d3f4e387455564c alias mpath2 } multipath { wwid 3600a0980383136312d3f4e387455564d alias mpath3 } multipath { wwid 3600a0980383136312d3f4e387455564e alias mpath4 } } ``` > wwid 可以從指令 multipath -l 取得 > > alias 可以設定任一名稱，LUN disks的順序可以從指令 sanlun lun show 取得 載入新設定 ``` systemctl reload multipathd ``` 執行 multipath -l，應該要顯示 WWID 與 Alias Name ``` mpath2 (3600a0980383136312d3f4e387455564c) dm-5 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=0 status=active | |- 12:0:0:1 sdo 8:224 active undef running | |- 13:0:0:1 sds 65:32 active undef running | |- 15:0:0:1 sdaa 65:160 active undef running | `- 16:0:0:1 sdae 65:224 active undef running `-+- policy='service-time 0' prio=0 status=enabled |- 10:0:0:1 sdg 8:96 active undef running |- 11:0:0:1 sdk 8:160 active undef running |- 14:0:0:1 sdw 65:96 active undef running `- 9:0:0:1 sdc 8:32 active undef running ``` ##### 開機掛載 iSCSI LUNs > 注意：若沒有以下設定，將導致系統無法正常開機。 編輯 /etc/fstab , 在 iSCSI disk 每一行都加上 \_netdev ``` #device mount point FS Options Backup fsck /dev/myvg/mylv /mydisk xfs _netdev 0 0 ``` 設定 netfs 服務自動啟動 ``` ## CentOS 7 systemctl enable remote-fs.target ## CentOS 4/5/6 chkconfig netfs on ``` ##### 加大 MTU 設定 網路卡預設 MTU 是 1500，這不適合 iSCSI 的應用，建議加大至 9000。除了 Linux 設定以外，網路連接的 Switch 與 iSCSI Storage (iSCSI Target) 也需要一併做調整。 RedHat 7.x) 檢查目前網路設置是否可接受大 frame 的網路封包傳遞 ``` UNSUCCESSFUL # ping -M do -c 4 -s 8196 10.1.1.21 PING 10.1.1.21 (10.1.1.21) 8185(8213) bytes of data. PING 10.1.1.21(10.1.1.21) 8196(8224) bytes of data. ping: local error: Message too long, mtu=1500 ping: local error: Message too long, mtu=1500 SUCCESSFUL # ping -M do -c 4 -s 1408 10.1.1.21 PING 10.1.1.21 (10.1.1.21) 1408(1436) bytes of data. 1416 bytes from 10.1.1.21: icmp_seq=1 ttl=58 time=224 ms ``` 立即調整 MTU (NOTE: 非永久性設置) ``` ip link set dev ens2f0 mtu 9000 ``` 永久設置方法，在 iSCSI 網路裝置的設定檔 ifcfg-ethXX，加上這行： ``` MTU="9000" ``` 重啟系統後生效。 ##### 擴充新硬碟 LUN disk 1\. iSCSI Storage 新增 LUN disk 並分派給要使用的 Linux host。 2\. 以下步驟都是 Linux host 要完成的。 3\. 掃描(discover)剛剛新增的 LUN disk ``` [root@bdb7-b ~]# /usr/bin/rescan-scsi-bus.sh Scanning SCSI subsystem for new devices Scanning host 0 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning host 1 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning host 2 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning host 3 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning for device 3 0 0 0 ... OLD: Host: scsi3 Channel: 00 Id: 00 Lun: 00 Vendor: HPE Model: DVDROM DUD0N Rev: UMD1 Type: CD-ROM ANSI SCSI revision: 05 Scanning host 4 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning host 5 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning host 6 for all SCSI target IDs, all LUNs Scanning host 7 for SCSI target IDs 0 1 2 3 4 5 6 7, all LUNs Scanning for device 7 0 0 0 ... ``` 4\. 使用 sanlun 指令檢查新 LUN disk ``` [root@bdb7-b ~]# sanlun lun show all controller(7mode/E-Series)/ device host lun vserver(cDOT/FlashRay) lun-pathname filename adapter protocol size product --------------------------------------------------------------------------------------------------------------- TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdaw host16 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdav host15 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdau host14 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdat host13 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdas host12 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdar host11 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdaq host10 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_6_vol/BDB7_B_6 /dev/sdap host9 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_5_vol/BDB7_B_5 /dev/sdao host15 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_5_vol/BDB7_B_5 /dev/sdan host16 iSCSI 500.1g cDOT TPEDBISCSISVM01 /vol/BDB7_B_4_vol/BDB7_B_4 /dev/sdam host16 iSCSI 500.1g cDOT ... ``` 5\. 使用 multipath 指令檢查新 LUN disk ``` [root@bdb7-b alang]# multipath -ll mpath2 (3600a098038313631305d4e2d6f774744) dm-6 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 9:0:0:1 sdf 8:80 active ready running | |- 12:0:0:1 sdt 65:48 active ready running | |- 16:0:0:1 sdah 66:16 active ready running | `- 15:0:0:1 sdai 66:32 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 11:0:0:1 sdg 8:96 active ready running |- 10:0:0:1 sde 8:64 active ready running |- 14:0:0:1 sdu 65:64 active ready running `- 13:0:0:1 sdv 65:80 active ready running mpath1 (3600a098038313631305d4e2d6f774743) dm-5 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 9:0:0:0 sdc 8:32 active ready running | |- 12:0:0:0 sdr 65:16 active ready running | |- 16:0:0:0 sdaf 65:240 active ready running | `- 15:0:0:0 sdag 66:0 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 11:0:0:0 sdd 8:48 active ready running |- 10:0:0:0 sdb 8:16 active ready running |- 13:0:0:0 sdq 65:0 active ready running `- 14:0:0:0 sds 65:32 active ready running 3600a098038313631305d4e2d6f77474a dm-26 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 9:0:0:5 sdap 66:144 active ready running | |- 12:0:0:5 sdas 66:192 active ready running | |- 15:0:0:5 sdav 66:240 active ready running | `- 16:0:0:5 sdaw 67:0 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 10:0:0:5 sdaq 66:160 active ready running |- 11:0:0:5 sdar 66:176 active ready running |- 13:0:0:5 sdat 66:208 active ready running `- 14:0:0:5 sdau 66:224 active ready running ... ``` 6\. 設定 LUN WWID 與 mpathX 的對應 編輯 `/etc/multipath.conf`: 將新的 wwid 與 alias 加上。 ``` # added by alang multipaths { multipath { wwid 3600a098038313631305d4e2d6f774743 alias mpath1 } multipath { wwid 3600a098038313631305d4e2d6f774744 alias mpath2 } multipath { wwid 3600a098038313631305d4e2d6f774745 alias mpath3 } multipath { wwid 3600a098038313631305d4e2d6f774746 alias mpath4 } multipath { wwid 3600a098038313631305d4e2d6f774747 alias mpath5 } multipath { wwid 3600a098038313631305d4e2d6f77474a alias mpath6 } } ``` 7\. 載入 multipath 設定 ```shell [root@bdb7-b alang]# systemctl reload multipathd [root@bdb7-b alang]# multipath -ll mpath2 (3600a098038313631305d4e2d6f774744) dm-6 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 12:0:0:1 sdt 65:48 active ready running | |- 15:0:0:1 sdai 66:32 active ready running | |- 16:0:0:1 sdah 66:16 active ready running | `- 9:0:0:1 sdf 8:80 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 10:0:0:1 sde 8:64 active ready running |- 11:0:0:1 sdg 8:96 active ready running |- 13:0:0:1 sdv 65:80 active ready running `- 14:0:0:1 sdu 65:64 active ready running mpath1 (3600a098038313631305d4e2d6f774743) dm-5 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 12:0:0:0 sdr 65:16 active ready running | |- 15:0:0:0 sdag 66:0 active ready running | |- 16:0:0:0 sdaf 65:240 active ready running | `- 9:0:0:0 sdc 8:32 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 10:0:0:0 sdb 8:16 active ready running |- 11:0:0:0 sdd 8:48 active ready running |- 13:0:0:0 sdq 65:0 active ready running `- 14:0:0:0 sds 65:32 active ready running mpath6 (3600a098038313631305d4e2d6f77474a) dm-26 NETAPP ,LUN C-Mode size=500G features='4 queue_if_no_path pg_init_retries 50 retain_attached_hw_handle' hwhandler='1 alua' wp=rw |-+- policy='service-time 0' prio=50 status=active | |- 12:0:0:5 sdas 66:192 active ready running | |- 15:0:0:5 sdav 66:240 active ready running | |- 16:0:0:5 sdaw 67:0 active ready running | `- 9:0:0:5 sdap 66:144 active ready running `-+- policy='service-time 0' prio=10 status=enabled |- 10:0:0:5 sdaq 66:160 active ready running |- 11:0:0:5 sdar 66:176 active ready running |- 13:0:0:5 sdat 66:208 active ready running `- 14:0:0:5 sdau 66:224 active ready running ``` 完成。新加的 disk mpath6 可以用 LVM 進行管理。 ##### 其他指令 顯示 disk path 更多資訊 - 主機磁碟名稱與 Storage LUN 名稱對應 - LUN 編號與 Size - Storage 的 path 狀態資訊 ``` [root@bdb7-a ~]# sanlun lun show -p ONTAP Path: TPEDBISCSISVM01:/vol/BDB7_A_2_vol/BDB7_A_2 LUN: 1 LUN Size: 500.1g Product: cDOT Host Device: mpath2(3600a0980383136312d3f4e387455564c) Multipath Policy: service-time 0 Multipath Provider: Native --------- ---------- ------- ------------ ---------------------------------------------- host vserver path path /dev/ host vserver state type node adapter LIF --------- ---------- ------- ------------ ---------------------------------------------- up primary sdo host12 TPEDBISCSISVM01_iSCSI2 up primary sds host13 TPEDBISCSISVM01_iSCSI2 up primary sdaa host15 TPEDBISCSISVM01_iSCSI1 up primary sdae host16 TPEDBISCSISVM01_iSCSI1 up secondary sdg host10 TPEDBISCSISVM01_iSCSI4 up secondary sdk host11 TPEDBISCSISVM01_iSCSI3 up secondary sdw host14 TPEDBISCSISVM01_iSCSI4 up secondary sdc host9 TPEDBISCSISVM01_iSCSI3 ``` 查詢 multipathd 的設定參數資訊 ``` multipathd show config ``` > 技巧: 連接不同廠牌的 Storage，預設狀態會套用不同的參數組設定，而這些參數的資訊可以從這指令獲得。 查詢目前 iSCSI connections ``` # iscsiadm -m session --op show tcp: [1] 10.18.104.32:3260,1038 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [2] 10.18.104.33:3260,1039 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [3] 10.18.104.34:3260,1040 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [4] 10.18.104.34:3260,1040 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [5] 10.18.104.33:3260,1039 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [6] 10.18.104.31:3260,1037 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [7] 10.18.104.31:3260,1037 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) tcp: [8] 10.18.104.32:3260,1038 iqn.1992-08.com.netapp:sn.58042162340f11e9892700a098e3ab45:vs.16 (non-flash) #iSCSI Logout All iscsiadm --mode node --logoutall=all #iSCSI Login All iscsiadm -m node -l ```