Since Linux does not really automatically handle target volume
remapping, you might be better of with explicitly tearing down the old
volume in Linux before any unmap/remap on the target. This is already
tricky enough to get right.
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Storage_Administration_Guide/removing_devices.html
Resizing of the same volume on the target is a special case which should
work, but even that one includes a rescan of the affected scsi devices
(paths) as pre-req.
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Storage_Administration_Guide/online-iscsi-resizing.html#resizing-fc-logical-units
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Storage_Administration_Guide/online-iscsi-resizing.html#idm8373264
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/DM_Multipath/online_device_resize.html
NB: None of the URLs provided are specific to a distro or device driver.
Those were just example documentation references I could find quickly.
On 07/11/2017 11:07 AM, Steffen Maier wrote:
On 07/11/2017 05:49 AM, liuqing@xxxxxxxxxx wrote:
Once a new arrived LUN mapped we will do rescan by "echo '- - -' >
/sys/class/scsi_host/host2/scan".
I was referring to a rescan of the scsi device,
https://www.ibm.com/support/knowledgecenter/linuxonibm/com.ibm.linux.z.lhdd/lhdd_t_fcp_wrk_rescan.html
not a scan of the Scsi_Host.
The latter likely keeps the old scsi device with its old properties
being oblivious to the volume remapping on the storage target; it's
about discovering new scsi devices previously not being known to Linux.
After rescan only the scsi_id tool give the right serial id, udevadm
still got the prvious one.
I have monitor the udev event by udevadm monitor while mapping a new
LUN to the host, who will reuse the original path. No add event is
triggerred, only dm-X emits a change event.
But if the original path is deleted(removed) then add event will be
triggerred.
Flush the old WWID could make the WWID correct but the size is still
incorrect as following. And 36005076300810eadf800000000000155 is
actually 5GB.
likely same reason as above
I built the tool using latest code and tried both attribute_id and
getuid_callout. The issue exist in both configuration.
Dear list,
We have a FC storage and using multipathd to manager the FC paths.
I've met an issue in this environment. The following is how to
recreate the issue.
=======
1. Map a LUN to host with LUN ID 0,
2. rescan fc_host, a new path will be found by multipath.
3. Unmap LUN 0. path will failed as following.
[root@localhost sys]# multipath -ll
Jul 10 18:41:50 | sdp: couldn't get asymmetric access state
Jul 10 18:41:50 | sdq: couldn't get asymmetric access state
36005076300810eadf800000000000156 dm-3 IBM,2145
size=8.0G features='2 queue_if_no_path retain_attached_hw_handler'
hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=0 status=enabled
| `- 2:0:0:0 sdp 8:240 failed faulty running
`-+- policy='service-time 0' prio=0 status=enabled
`- 2:0:1:0 sdq 65:0 failed faulty running
4. Map another LUN which have different ID_SERIAL but with the same
LUN ID(0).
Did you "rescan" the SCSI device via sysfs to let Linux know that this
is now in fact a different device?
AFAIK, Linux decodes SCSI sense data for LUNs remapped on the storage
target and emits a udev event, but I'm not aware of any default udev
rule that would actually react. The kernel itself does not react other
than creating the uevent.
--
Mit freundlichen Grüßen / Kind regards
Steffen Maier
Linux on z Systems Development
IBM Deutschland Research & Development GmbH
Vorsitzende des Aufsichtsrats: Martina Koederitz
Geschaeftsfuehrung: Dirk Wittkopp
Sitz der Gesellschaft: Boeblingen
Registergericht: Amtsgericht Stuttgart, HRB 243294
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