On 03/10, Rikimaru Honjo wrote: > Hello Gorka, > > On 2017/10/02 20:37, Gorka Eguileor wrote: > > On 02/10, Rikimaru Honjo wrote: > > > Hello, > > > > > > I'd like to discuss about the following bug of os-brick. > > > > > > * os-brick's iscsi initiator unexpectedly reverts node.startup from > > > "automatic" to "manual". > > > https://bugs.launchpad.net/os-brick/+bug/1670237 > > > > > > The important point of this bug is: > > > > > > When os-brick initializes iscsi connections: > > > 1. os-brick will run "iscsiadm -m discovery" command if we use iscsi > > > multipath. > > > > This only happens with a small number of cinder drivers, since most > > drivers try to avoid the discovery path due to the number of > > disadvantages it presents for a reliable deployment. The most notorious > > issue is that the path to the discovery portal on the attaching node is > > down you cannot attach the volume no matter how many of the other paths > > are up. > > > > > > > > > 2. os-brick will update node.startup values to "automatic" if we use > > > iscsi. > > > 3. "iscsiadm -m discovery" command will recreate iscsi node > > > repositories.[1] > > > As a result, node.startup values of already attached volumes will be > > > revert > > > to default(=manual). > > > > > > Gorka Eguileor and I discussed how do I fix this bug[2]. > > > Our idea is this: > > > > > > 1. Confirm node.startup values of all the iscsi targets before running > > > discovery. > > > 2. Re-update node.startup values of all the iscsi targets after running > > > discovery. > > > > > > But, I afraid that this operation will take a long time. > > > I ran showing & updating node.startup values 100 times for researching. > > > As a result, it took about 4 seconds. > > > When I ran 200 times, it took about 8 seconds. > > > I think this is a little long. > > > > > > If we use multipath and attach 25 volumes, 100 targets will be created. > > > I think that updating 100 times is a possible use case. > > > > > > How do you think about it? > > > Can I implement the above idea? > > > > > > > The approach I proposed is on the review is valid, the flaw is in the > > specific implementation, you are doing 100 request where 4 would > > suffice. > > > > You don't need to do a request for each target-portal tuple, you only > > need to do 1 request per portal, which reduces the number of calls to > > iscsiadm from 100 to 4 in the case you mention. > > > > You can check all targets for an IP with: > > iscsiadm -m node -p IP > > > > This means that the performance hit from having 100 or 200 targets > > should be negligible. > > I have one question. > > I can see node.startup values by 1 request per portal as you said. > > But, may I update values by 1 request per portal? > Updating values has been done by 1 request per target until now. > So I think my patch should update values in same way(=1 request per target). >
If all the targets on the same portal had the original same value you should just make a single call after the discovery that changes them all, at least that would be my preference. > > Cheers, > > Gorka. > > > > > > > > > [1]This is correct behavior of iscsiadm. > > > > > > https://github.com/open-iscsi/open-iscsi/issues/58#issuecomment-325528315 > > > [2]https://bugs.launchpad.net/os-brick/+bug/1670237 > > > -- > > > _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ > > > Rikimaru Honjo > > > E-mail:honjo.rikim...@po.ntt-tx.co.jp > > > > > > > > > > > > __________________________________________________________________________ > > > OpenStack Development Mailing List (not for usage questions) > > > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > __________________________________________________________________________ > > OpenStack Development Mailing List (not for usage questions) > > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > > > > > > -- > _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ > ★社名とメールアドレスが変わりました。 > > NTTテクノクロス株式会社 > クラウド&セキュリティ事業部 第二事業ユニット(CS2BU) > 本上力丸 > TEL. :045-212-7539 > E-mail:honjo.rikim...@po.ntt-tx.co.jp > 〒220-0012 > 横浜市西区みなとみらい4丁目4番5号 > 横浜アイマークプレイス 13階 > > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev