On Wednesday, September 12, 2018 2:14:05 PM CEST J. Roeleveld wrote: > On September 12, 2018 7:43:12 AM UTC, "Stefan G. Weichinger" <li...@xunil.at> wrote: > >Am 12.09.18 um 08:42 schrieb J. Roeleveld: > >> On Tuesday, September 11, 2018 11:48:59 AM CEST Stefan G. Weichinger > > > >wrote: > >>> At first I emerged latest stable gentoo-sources, enabled these flags > > > >and > > > >>> compiled ... but the lpfc module didn't detect the SAN devices > >>> correctly, so I switched back to 4.1.15 (mark this as another todo > > > >here > > > >>> ... sooner or later I want a more recent kernel working with lpfc > > > >... I > > > >>> have no clue about multipath so far) > >> > >> I found multipath quite "simple" to implement when following the > > > >documentation > > > >> for this. > > > >*which* documentation, please? > > > >with the newer kernel I got: > > > >[ 864.521464] lpfc 0000:02:00.1: 1:1303 Link Up Event x7b received > >Data: x7b x0 x20 x0 x0 x0 0 > >[ 868.693743] lpfc 0000:02:00.0: 0:1305 Link Down Event x7c received > >Data: x7c x20 x80011 x0 x0 > >[ 869.523664] lpfc 0000:02:00.0: 0:1303 Link Up Event x7d received > >Data: x7d x0 x20 x0 x0 x0 0 > >[ 873.691535] lpfc 0000:02:00.1: 1:1305 Link Down Event x7c received > >Data: x7c x20 x80011 x0 x0 > >[ 874.521185] lpfc 0000:02:00.1: 1:1303 Link Up Event x7d received > >Data: x7d x0 x20 x0 x0 x0 0 > >[ 878.694259] lpfc 0000:02:00.0: 0:1305 Link Down Event x7e received > >Data: x7e x20 x80011 x0 x0 > > > > > >and no /dev/sdX created for the relevant LUN (is that the term?) > > > >I see a multipath.conf on the system, will try to understand that. > > Multipath devices end up under /dev/mapper/... > > I think it was Redhat who had most decent docs. Will check my bookmarks > tonight and give you the full list.
Bit sooner: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/ dm_multipath/mpio_overview https://www.thegeekdiary.com/beginners-guide-to-device-mapper-dm-multipathing/ I use multipath from a SAS-controller to a dual-backplane and SAS-disks. >From the controller, I have 2 paths to each disk, which means I have twice the amount of "sd?" entries. == # multipath -l 35000cca25d8ec910 dm-4 HGST,HUS726040ALS210 size=3.6T features='1 retain_attached_hw_handler' hwhandler='0' wp=rw |-+- policy='service-time 0' prio=0 status=active | `- 0:0:7:0 sdh 8:112 active undef running `-+- policy='service-time 0' prio=0 status=enabled `- 0:0:20:0 sdt 65:48 active undef running == (This is only the first device) It shows that device "35000cca25d8ec910" is mapped to "sdh" and "sdt". To use the disk correctly, I need to access "/dev/mapper/35000cca25d8ec910", which is: # ls -lsa /dev/mapper/35000cca25d8ec910 0 lrwxrwxrwx 1 root root 7 Sep 4 11:43 /dev/mapper/35000cca25d8ec910 -> ../ dm-4 I have "multipathd" in the "boot" runlevel. Version info: # eix -I multipath [I] sys-fs/multipath-tools Available versions: 0.5.0-r1 0.6.4-r1{tbz2} ~0.7.6^t ~0.7.7^t {rbd systemd KERNEL="linux"} Installed versions: 0.6.4-r1{tbz2}(10:51:01 AM 01/23/2018)(-rbd - systemd) Homepage: http://christophe.varoqui.free.fr/ Description: Device mapper target autoconfig # uname -a Linux san1 4.9.76-gentoo-r1-generic #1 SMP Tue Jan 23 12:05:11 CET 2018 x86_64 Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz GenuineIntel GNU/Linux As for the terms, a LUN is a Logical disk provided by a SAN to a different system. I have multipath inside my SAN and have a single path to iSCSI clients. (Single switch with bonded NICs) -- Joost
