From: Martin Wilck <mwilck@suse.com>
To: Benjamin Marzinski <bmarzins@redhat.com>
Cc: dm-devel@redhat.com
Subject: Re: [PATCH 0/3] New approach at handling changed WWIDs
Date: Tue, 26 Mar 2019 09:21:41 +0100 [thread overview]
Message-ID: <1567203fadd7bec50d0862d99a067dffdd2329e6.camel@suse.com> (raw)
In-Reply-To: <20190325222722.GP13295@octiron.msp.redhat.com>
On Mon, 2019-03-25 at 17:27 -0500, Benjamin Marzinski wrote:
>
> > One remark: With the kernel exporting the VPD pages in sysfs
> > and my late "multipath -u" patch series, udev should be able to
> > process
> > uevents for path devices without a single actual device IO. (*)
> > While there are still possible causes for udev processing to get
> > stuck,
> > this would make it much less likely.
>
> For reasons I don't understand, not all devices get a vpd_pg83 sysfs
> file, even though they clearly have a page 0x83, since multipath and
> sg_inq can read from it via ioctl. I have a device like this. This
> is
> quite possibly a kernel issue that should get fixed, but regardless,
> it's been there for a while, and I just cheked and it still exists in
> the 5.0.0-rc6 kernel.
This is intentional. The kernel applies conservative heuristics to
determine whether these VPDs are supported. See the comment in
scsi_device_supports_vpd(). Sometimes the kernel gets it wrong, usually
because the device claims to be a pre-SCSI_SPC_2 device. Such devices
should be fixed with the BLIST_TRY_VPD_PAGES device flag if they do
support the DI VPD.
OPEN-V devices are a notorious example. But meanwhile the blist flags
are in place for them.
Regards
Martin
--
Dr. Martin Wilck <mwilck@suse.com>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
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prev parent reply other threads:[~2019-03-26 8:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-18 12:12 [PATCH 0/3] New approach at handling changed WWIDs Martin Wilck
2019-03-18 12:12 ` [PATCH 1/3] multipathd: handle changed wwids by removal and addition Martin Wilck
2019-03-18 12:12 ` [PATCH 2/3] multipathd: remove "wwid_changed" path attribute Martin Wilck
2019-03-18 12:12 ` [PATCH 3/3] multipathd: ignore "disable_changed_wwids" Martin Wilck
2019-03-19 17:11 ` [PATCH 0/3] New approach at handling changed WWIDs Benjamin Marzinski
2019-03-19 18:44 ` Martin Wilck
2019-03-20 8:37 ` Martin Wilck
2019-03-21 22:31 ` Benjamin Marzinski
2019-03-22 11:28 ` Martin Wilck
2019-03-22 14:13 ` Benjamin Marzinski
2019-03-25 22:27 ` Benjamin Marzinski
2019-03-26 8:21 ` Martin Wilck [this message]
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