Rebuild SG File on Solaris

Drives are not being recognized by the OS - Steps to rebuild the /dev/sg/* and /dev/rmt/* devices on a Solaris Master or Media server

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Details:

Here are the basic steps to rebuild the /dev/sg/* and /dev/rmt/* devices on a Solaris server without rebooting.

1.  Create a backup copy of the current st.conf file:
# cp /kernel/drv/st.conf /kernel/drv/st.conf.`date +%m%d%y_%H%M%S`

2.  Move the existing sg.conf to a backup (this must be a move, otherwise a later step will fail):
# mv /kernel/drv/sg.conf /kernel/drv/sg.conf.`date +%m%d%y_%H%M%S`

3.  Create a backup copy of the current devlink.tab file:
# cp /etc/devlink.tab /etc/devlink.tab.`date +%m%d%y_%H%M%S`

4.  Delete SCSI targets/LUNs from the /kernel/drv/st.conf file:
name="st" class="scsi"
       target=0 lun=0;

All of these entries should be removed, otherwise duplicates will be added later.

5.  Delete SCSI targets/LUNs from /etc/devlink.tab.  This is typically the section near the end of the file and the entries are typically of the form:

# begin SCSA Generic devlinks file - creates nodes in /dev/sg
type=ddi_pseudo;name=sg;addr=0,0;       sg/c\N0t0l0
type=ddi_pseudo;name=sg;addr=1,0;       sg/c\N0t1l0
type=ddi_pseudo;name=sg;addr=2,0;       sg/c\N0t2l0
type=ddi_pseudo;name=sg;addr=3,0;       sg/c\N0t3l0
type=ddi_pseudo;name=sg;addr=4,0;       sg/c\N0t4l0
type=ddi_pseudo;name=sg;addr=5,0;       sg/c\N0t5l0
type=ddi_pseudo;name=sg;addr=6,0;       sg/c\N0t6l0
type=ddi_pseudo;name=sg;addr=0,1;       sg/c\N0t0l1
type=ddi_pseudo;name=sg;addr=1,1;       sg/c\N0t1l1
type=ddi_pseudo;name=sg;addr=2,1;       sg/c\N0t2l1
type=ddi_pseudo;name=sg;addr=3,1;       sg/c\N0t3l1
type=ddi_pseudo;name=sg;addr=4,1;       sg/c\N0t4l1
type=ddi_pseudo;name=sg;addr=5,1;       sg/c\N0t5l1
type=ddi_pseudo;name=sg;addr=6,1;       sg/c\N0t6l1
# end SCSA devlinks

Everything in this section should be removed, inclusive of the beginning and ending lines.

6.  Change to the appropriate directory to run commands:
# cd /usr/openv/volmgr/bin/driver

7.  Generate the configuration files (st.conf, sg.conf and sg.links):
../sg.build all -mt -ml

Note: You will need to know what the max_target and max_lun values will need to be (this is the maximum SCSI Target and LUN value).

8.  Append the generated st.conf entries to the OS configuration file:
# cat st.conf >> /kernel/drv/st.conf

9.  Unload the sg driver:
# rem_drv sg

10. Use the provided script to re-create the /kernel/drv/sg.conf file, append the SCSA entries to /etc/devlink.tab and reload the sg driver:
# ./sg.install

11. Now sgscan should see the appropriate devices:
# /usr/openv/volmgr/bin/sgscan all conf -v