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From: NeilBrown <neilb@suse.com>
To: ian_bruce@mail.ru, linux-raid@vger.kernel.org
Subject: Re: [BUG] non-metadata arrays cannot use more than 27 component devices
Date: Mon, 27 Feb 2017 16:55:56 +1100	[thread overview]
Message-ID: <87y3wsp47n.fsf@notabene.neil.brown.name> (raw)
In-Reply-To: <20170224040816.41f2f372.ian_bruce@mail.ru>

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On Fri, Feb 24 2017, ian_bruce@mail.ru wrote:

> When assembling non-metadata arrays ("mdadm --build"), the in-kernel
> superblock apparently defaults to the MD-RAID v0.90 type. This imposes a
> maximum of 27 component block devices, presumably as well as limits on
> device size.
>
> mdadm does not allow you to override this default, by specifying the
> v1.2 superblock. It is not clear whether mdadm tells the kernel to use
> the v0.90 superblock, or the kernel assumes this by itself. One or other
> of them should be fixed; there does not appear to be any reason why the
> v1.2 superblock should not be the default in this case.

Can you see if this change improves the behavior for you?

NeilBrown


diff --git a/drivers/md/md.c b/drivers/md/md.c
index ba485dcf1064..e0ac7f5a8e68 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6464,9 +6464,8 @@ static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
 	mddev->layout        = info->layout;
 	mddev->chunk_sectors = info->chunk_size >> 9;
 
-	mddev->max_disks     = MD_SB_DISKS;
-
 	if (mddev->persistent) {
+		mddev->max_disks     = MD_SB_DISKS;
 		mddev->flags         = 0;
 		mddev->sb_flags         = 0;
 	}


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  parent reply	other threads:[~2017-02-27  5:55 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-24 12:08 [BUG] non-metadata arrays cannot use more than 27 component devices ian_bruce
2017-02-24 15:20 ` Phil Turmel
2017-02-24 16:40   ` ian_bruce
2017-02-24 20:46     ` Phil Turmel
2017-02-25 20:05       ` Anthony Youngman
2017-02-25 22:00         ` Phil Turmel
2017-02-25 23:30           ` Wols Lists
2017-02-25 23:41             ` Phil Turmel
2017-02-25 23:55               ` Wols Lists
2017-02-26  0:07                 ` Phil Turmel
2017-03-01 15:02                   ` Wols Lists
2017-03-01 17:23                     ` Phil Turmel
2017-03-01 18:13                       ` Phil Turmel
2017-03-01 19:50                         ` Anthony Youngman
2017-03-01 22:20                           ` Phil Turmel
2017-02-27  5:55 ` NeilBrown [this message]
2017-02-28 10:25   ` ian_bruce
2017-02-28 20:29     ` NeilBrown
2017-03-01 13:05       ` ian_bruce

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