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Lun rescan not discovering newly allocated clones
We are performing some testing which requires us to remove all R2 volumes from a server and present clones of the R2's instead. When we recently tried this the clones did not show up after a rescan. It actually took a reboot of the servers to allow the luns to show up. The servers having problems are RHEL 4.7 (64 bit) running Oracle RAC. This worked fine on similar RHEL servers with RAC, but we chose to use dynamic luns on this server during this operation. Before this operation they were not dynamically masked.
We performed the following to accomplish this:
symmask -sid XXX remove devs DDA,DDB,DDC -wwn NNNNNNNNNNNNN -dir YY -p Z
symmask -sid XXX add devs FFA,FFB,FFC -wwn NNNNNNNNNNNNN -dir YY -p Z -dynamic_lun
symmask -sid XXX refresh
Any known issues with RHEL and dynamic masking?
dynamox
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June 23rd, 2010 12:00
we've had mixed results with Linux discovering new devices, sometimes it picks them up on the fly with no issues and sometimes we have to bounce the box. It would be ineresting to try running rescan after you unmasked R2, then "powermt check" to remove dead paths ..mask clones, rescan and "powermt config"
dynamox
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June 23rd, 2010 08:00
been using dynamic_lun since redhat 4.5 (we do have RAC as well), have not had any issues. Are clones presented from the same FAs as the R2s ?
NathanK1
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June 23rd, 2010 10:00
We run a script provided by Emulex to perform the rescan.
In that script I see:
echo "scsi add-single-device $host 0 $dec_target $lun" >/proc/scsi/scsi
echo Scanning lpfc HBA instance with scsi host number : $host;
echo '- - -' > /sys/class/scsi_host/host$host/scan
NathanK1
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June 23rd, 2010 10:00
Yes they are on the same FA's.
dynamox
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June 23rd, 2010 10:00
how do you rescan ? Something like this:
echo "1" > /sys/class/fc_host/host0/issue_lip
echo "- - -" > /sys/class/scsi_host/host0/scan
echo "1" > /sys/class/fc_host/host1/issue_lip
echo "- - -" > /sys/class/scsi_host/host1/scan