Linux - XP1024 - Failover using LVM PVLinks?

[Kermes78]

Good morning,
is there any way to reach failover funcionality using Linux RHEL5 lvm with a couple of paths to one XP1024 LUN?

Some info:
[root@svl06 ~]# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: OPEN-E*15 Rev: 2114
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: HP Model: OPEN-E*15 Rev: 2114
Type: Direct-Access ANSI SCSI revision: 02

These corresponds to /dev/sdb and /dev/sdd devices. I've checked them (same LUN, just different path using SANsurfer from Qlogic)

We have one VG using one of the PVs:
--- Physical volumes ---
PV Name /dev/sdb1
PV UUID zytcmV-fa9l-tsKi-FVCF-2MXV-ektu-r7t2a1
PV Status allocatable
Total PE / Free PE 52097 / 1

The problem is that we can't add the second PVLink, as we normally do in HPUX, to the VG:
[root@svl06 ~]# vgextend vg02 /dev/sdd1
/dev/sdd1 not identified as an existing physical volume
Unable to add physical volume '/dev/sdd1' to volume group 'vg02'.

Any comment is really welcomed!

[Heironimus · Accepted solution]

pvlinks is an HP-UX thing. These days the two standard methods for doing it on Linux with qlogic cards are the qlogic driver's built-in failover and the dm-multipath generic multipath driver. I think qlogic and the Linux distributions are pushing toward dm-multipath as the standard solution, but qlogic failover has been around longer (Red Hat only added dm-multipath in RHEL4u2).

[Kermes78]

Thanks for your answer!

We will try to use one of that methods... qla2xxx or dm-multipath.

Thanks!

[skt_skt]

other option would be power path/secure path which ever is applicable. We use PP with EMC storages.

[Heironimus]

You'd probably want PowerPath if you had an EMC. You can also use qlogic's SanSurfer for some additional load balancing options with the qlogic driver. HP's SecurePath, however, was pretty much a dead product the last time I looked - HP had no plans to support 2.6 kernels and said to use the qlogic failover driver (they had an HP-certified package).