From: Joe Thornber <thornber@redhat.com>
To: LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] when bringing dm-cache online, consumes all memory and reboots
Date: Mon, 23 Mar 2020 08:26:08 +0000 [thread overview]
Message-ID: <20200323082608.7i6wzq2t3k24hzun@reti> (raw)
In-Reply-To: <CACRKOwz_fOJiTVhbUqJR_EaxrKbf2bk+wb6LYOy0yWDkvt+buw@mail.gmail.com>
On Sun, Mar 22, 2020 at 10:57:35AM -0700, Scott Mcdermott wrote:
> have a 931.5 GibiByte SSD pair in raid1 (mdraid) as cache LV for a
> data LV on 1.8 TebiByte raid1 (mdraid) pair of larger spinning disk.
> these disks are hosted by a small 4GB big.little ARM system
> running4.4.192-rk3399 (armbian 5.98 bionic). parameters were set
> with: lvconvert --type cache --cachemode writeback --cachepolicy smq
> --cachesettings migration_threshold=10000000
If you crash then the cache assumes all blocks are dirty and performs
a full writeback. You have set the migration_threshold extremely high
so I think this writeback process is just submitting far too much io at once.
Bring it down to around 2048 and try again.
- Joe
next prev parent reply other threads:[~2020-03-23 8:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-22 17:57 [linux-lvm] when bringing dm-cache online, consumes all memory and reboots Scott Mcdermott
2020-03-23 8:26 ` Joe Thornber [this message]
2020-03-23 9:57 ` Zdenek Kabelac
2020-03-23 16:26 ` John Stoffel
2020-03-23 22:02 ` Scott Mcdermott
2020-03-24 9:43 ` Zdenek Kabelac
2020-03-24 11:37 ` Gionatan Danti
2020-03-24 15:09 ` Zdenek Kabelac
2020-03-24 22:35 ` Gionatan Danti
2020-03-25 8:55 ` Zdenek Kabelac
2020-03-23 21:35 ` Scott Mcdermott
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