On Tue, Sep 4, 2018 at 9:51 PM Nir Soffer <nsof...@redhat.com> wrote:

> On Tue, Sep 4, 2018 at 11:30 AM Fabrice Bacchella <
> fabrice.bacche...@orange.fr> wrote:
>
>>
>>
>> > Le 3 sept. 2018 à 19:15, Nir Soffer <nsof...@redhat.com> a écrit :
>>
>> Thank you for you help, but I'm still not out of trouble.
>>
>> >
>> > On Mon, Sep 3, 2018 at 8:01 PM Fabrice Bacchella <
>> fabrice.bacche...@orange.fr> wrote:
>> >
>> >> Le 3 sept. 2018 à 18:31, Nir Soffer <nsof...@redhat.com> a écrit :
>> >>
>> >> On Mon, Sep 3, 2018 at 5:07 PM Fabrice Bacchella <
>> fabrice.bacche...@orange.fr> wrote:
>> >> In the release notes, I see:
>> >>
>> >> • BZ 1622700 [downstream clone - 4.2.6] [RFE][Dalton] - Blacklist all
>> local disk in multipath on RHEL / RHEV Host (RHEL 7.5)
>> >> Feature:
>> >> Blacklist local devices in multipath.
>> >>
>> >> Reason:
>> >> multipath repeatedly logs irrelevant errors for local devices.
>> >>
>> >> Result:
>> >> Local devices are blacklisted, and no irrelevant errors are logged
>> anymore.
>> >>
>> >> What defines a local disk ? I'm using a SAN on SAS. For many peoples,
>> SAS is only for local disks, but that's not the case. Will other 4.2.6 will
>> detect that ?
>> >>
>> >> We don't have any support for SAS.
>> >>
>> >> If you SAS drives are attached to the host using FC or iSCSI, you are
>> fine.
>> >
>> > Nope, they are attached using SAS.
>> >
>> > I guess oVirt see them as FCP devices?
>>
>> yes, in ovirt UI, I've configured my storage to be on FCP, and everything
>> worked well since 3.6.
>>
>> >
>> > Are these disks connected to multiple hosts?
>>
>> Yes, that's a real SAN, multi-attached to HPE's blades
>> >
>> > Please share the output of:
>> >
>> >     vdsm-client Host getDeviceList
>>
>> Things are strange:
>>
>>     {
>>         "status": "used",
>>         "vendorID": "HP iLO",
>>         "GUID": "HP_iLO_LUN_01_Media_0_000002660A01-0:1",
>>         "capacity": "1073741824",
>>         "fwrev": "2.10",
>>         "discard_zeroes_data": 0,
>>         "vgUUID": "",
>>         "pathlist": [],
>>         "pvsize": "",
>>         "discard_max_bytes": 0,
>>         "pathstatus": [
>>             {
>>                 "capacity": "1073741824",
>>                 "physdev": "sddj",
>>                 "type": "FCP",
>>                 "state": "active",
>>                 "lun": "1"
>>             }
>>         ],
>>         "devtype": "FCP",
>>         "physicalblocksize": "512",
>>         "pvUUID": "",
>>         "serial": "",
>>         "logicalblocksize": "512",
>>         "productID": "LUN 01 Media 0"
>>     },
>> ...
>>     {
>>         "status": "used",
>>         "vendorID": "HP",
>>         "GUID": "3600c0ff0002631c42168f15601000000",
>>         "capacity": "1198996324352",
>>         "fwrev": "G22x",
>>         "discard_zeroes_data": 0,
>>         "vgUUID": "xGCmpC-DhHe-3v6v-6LJw-iS24-ExCE-0Hv48U",
>>         "pathlist": [],
>>         "pvsize": "1198698528768",
>>         "discard_max_bytes": 0,
>>         "pathstatus": [
>>             {
>>                 "capacity": "1198996324352",
>>                 "physdev": "sdc",
>>                 "type": "FCP",
>>                 "state": "active",
>>                 "lun": "16"
>>             },
>>             {
>>                 "capacity": "1198996324352",
>>                 "physdev": "sds",
>>                 "type": "FCP",
>>                 "state": "active",
>>                 "lun": "16"
>>             },
>>
>>
>> ...
>>
>> The first one is an embedded flash drive:
>> lrwxrwxrwx 1 root root 10 Jul 12 17:11
>> /dev/disk/by-id/usb-HP_iLO_LUN_01_Media_0_000002660A01-0:1 -> ../../sddj
>> lrwxrwxrwx 1 root root 10 Jul 12 17:11
>> /dev/disk/by-path/pci-0000:00:14.0-usb-0:3.1:1.0-scsi-0:0:0:1 -> ../../sddj
>>
>> So why "type": "FCP",  ?
>>
>
> "FCP" actually means "not iSCSI". This why your sas storage works while
> oVirt does
> know anything about sas.
>
> This is why the blacklist by protocol feature was introduced in 7.5, to
> multipath can grab
> only shared storage, and avoid grabbing local devices like your SSD.
> See https://bugzilla.redhat.com/show_bug.cgi?id=1593459
>
> According to this bug:
> https://bugzilla.redhat.com/show_bug.cgi?id=1607749
>
> The fix is available in:
> device-mapper-multipath-0.4.9-119.el7_5.1.x86_64
>
> Which device-mapper-multipath package are you using?
>
>
>
>> The second is indeed a SAS drives behind a SAS SAN (a MSA 2040 SAS from
>> HPE).
>>
>>
>> >  ...
>> > Where do I find the protocol multipath thinks the drives are using ?
>> >
>> > multipath.conf(5) says:
>> >
>> >        The protocol strings that multipath recognizes are scsi:fcp,
>> scsi:spi, scsi:ssa, scsi:sbp,
>> >        scsi:srp, scsi:iscsi, scsi:sas, scsi:adt, scsi:ata, scsi:unspec,
>> ccw, cciss, nvme,  and
>> >        undef.  The protocol that a path is using can be viewed by
>> running multipathd show
>> >        paths format "%d %P"
>>
>> I have a centos 7.5:
>>
>> lsb_release -a
>> LSB Version:    :core-4.1-amd64:core-4.1-noarch
>> Distributor ID: CentOS
>> Description:    CentOS Linux release 7.5.1804 (Core)
>> Release:        7.5.1804
>> Codename:       Core
>>
>> and I don't have this in multipath.conf(5). But blacklist_exceptions
>> exists.
>>
>> The given command don't works:
>> multipathd show paths format "%d %P"
>> dev
>> sddi
>> sddj
>> sda
>> ...
>
>
> It looks like your system does not have the fix.
>
>
>> > So this should work:
>> >
>> > blacklist_exceptions {
>> >         protocol "(scsi:fcp|scsi:iscsi|scsi:sas)"
>>
>>
>> > }
>> >
>> > The best way to make this change is to create a dropin conf file,
>> > and not touch /etc/multipath.conf, so vdsm will be able to update later.
>> >
>> > $cat /etc/multipath/conf.d/local.conf
>> > blacklist_exceptions {
>> >         protocol "(scsi:fcp|scsi:iscsi|scsi:sas)"
>>
>>
>> > }
>>
>> The header in /etc/multipath.conf says:
>>
>> # The recommended way to add configuration for your storage is to add a
>> # drop-in configuration file in "/etc/multipath/conf.d/<mydevice>.conf".
>>
>> Does <mydevice> have a signification or it's just a meaningless string
>> that can be used as a reminder ?
>>
>
> mydevice is not a good name, this is just arbitrary name that is useful to
> you,
> multipath does not care about the name.
>
> I'll update this to "my.conf" to make this more clear
>

For reference, I just installed multipath on CentOS:

# cat /etc/redhat-release
CentOS Linux release 7.5.1804 (Core)

# rpm -q device-mapper-multipath
device-mapper-multipath-0.4.9-119.el7_5.1.x86_64

# lsblk
NAME                    MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                       8:0    0   50G  0 disk
├─sda1                    8:1    0    1G  0 part /boot
└─sda2                    8:2    0   49G  0 part
  ├─centos_voodoo4-root 253:0    0 45.1G  0 lvm  /
  └─centos_voodoo4-swap 253:1    0  3.9G  0 lvm  [SWAP]
sr0                      11:0    1 1024M  0 rom

# multipathd show paths format "%d %P"
dev protocol
sda scsi:unspec

# man multipath.conf
...
blacklist section
...
       protocol         Regular expression of the protocol to be excluded.
See below for a list of recognized protocols
...
       The  protocol strings that multipath recognizes are scsi:fcp,
scsi:spi, scsi:ssa, scsi:sbp, scsi:srp, scsi:iscsi, scsi:sas, scsi:adt,
scsi:ata, scsi:unspec, ccw, cciss, nvme, and
       undef.  The protocol that a path is using can be viewed by running
multipathd show paths format "%d %P"

Nir
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