http://ssl.webangel.ie/ 2026-05-28T10:33:59+00:00 http://ssl.webangel.ie/ http://ssl.webangel.ie/lib/exe/fetch.php?media=wiki:dokuwiki.svg text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:add-luns&rev=1759830220&do=diff Adding Luns I have not tried this procedure I ussually recommend rebooting server Adding a LUN To add a new LUN to an existing PowerPath configuration: * Ordered List ItemScan the bus for the LUNs. * Ensure that the new LUN is created on the storage side and recognized by Linux. text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:daemons&rev=1759830220&do=diff DM-Multipath Daemons After you edit the multipath.conf file you can run the following commands to load and start it as well as to show you wht is detected. modprobe dm-multipath service multipathd start multipath -v2 The multipath -v2 command prints out multipathed paths that show which devices are multipathed. If the command does not print anything out, ensure that all SAN connections are set up properly and the system is multipathed. text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:dm-multipath-conf&rev=1759830220&do=diff dm-multipath.conf The multipath.conf files blacklists EVERYTHING by default. So ensure the first lines are commented out blacklist { devnode "*" } After commenting out the general blacklist you can then specify general types of devices to black list or even individual devices. text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:dm-multipath&rev=1759830220&do=diff DM-Multipath Device Mapper Commands Command Descriptions multipath -h Prints usage information multipath -ll Displays the current multipath topology using all available information (sysfs, the device mapper, path checkers, and so on) text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:documentation&rev=1759830220&do=diff Documentation Official Redhat Documentation [ Accessing HBA information] [ Adding or Removing Luns] text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:fiber&rev=1759830220&do=diff Linux and Fiber As of RHEL 3.7 most of the drivers for HBAs are included on the kernel so no need to install extra drivers. Getting information about the HBAs though is a different story. Pre 2.6.11 kernels RHEl4.1 and older Older Kernels Post 2.6.11 Kernels text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:iscsi&rev=1759830220&do=diff Linux iSCSI This was first supported on RHEL 3. The procedure to set it up is the same for RHEL 3 and 4. For newer versions of RHEL the procedure has changed a bit. iSCSI in RHEL 3 and 4 iSCSI in RHEL3 and RHEL4 iSCSI in RHEL 5 and Higher FIXME need to test this iSCSI in RHEL5 and Newer Documentation text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:local-disks&rev=1759830220&do=diff Configure DM Multipath to Ignore Local Disks Details from Redhat Manual * Determine which disks are the internal disks and mark them as the ones to blacklist. In this example, /dev/sda is the internal disk. Note that as originally configured in the default multipath configuration file, executing the text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:lvm&rev=1759830220&do=diff Using LVM LVM is Linux's Volume Management. It is a default during installation Creating a new LVM This is done in 3 main steps - Create a new partition on a disk and marking as type 8e then run pvcreate /dev/sdX# - Create a new Volume group set run **vgcreate ** text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:mpathconf&rev=1759830220&do=diff Mpathconf You set up multipath with the mpathconf utility, which creates the multipath configuration file /etc/multipath.conf. * If the /etc/multipath.conf file already exists, the mpathconf utility will edit it. * If the /etc/multipath.conf file does not exist, the mpathconf utility will use the text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:newer-kernel&rev=1759830220&do=diff Newer Kernels post 2.6.11 Neer kernels have introduced a lot of changes to the HBA drivers. Now the drivers store the information on various entries in the /sys folder. There is no central information repository of information as on previous versions text/html 2025-10-07T09:43:40+00:00 Anonymous (anonymous@undisclosed.example.com) http://ssl.webangel.ie/doku.php?id=linux:linux-san:older-kernels&rev=1759830220&do=diff Older Kernels Details fo the HBAs was available under /proc/scsi/qlxxx #for Qlogic cards /proc/scsi/lpfc #for Emulex cards you would find to numbered files that indicate the PCI slot that the card was sitting on. so for example cat /proc/scsi/ql23xx/1 QLogic PCI to Fibre Channel Host Adapter for QLA2460: Firmware version: 4.00.23, Driver version 7.07.05 Entry address = f888d060 Request Queue = 0x37280000, Response Queue = 0x37270000 Request Queue count= 512, Response Queue co…