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From: Alexander Pashaliyski <al.pashaliyski@gmail.com>
To: dm-devel@redhat.com
Subject: dm-cache issue
Date: Mon, 14 Nov 2016 17:02:47 +0200	[thread overview]
Message-ID: <CAJV2nOTJoWWc=N80e6WCpZUh6ZRxvCW8Wt=aZWTyYSKso+kQ5Q@mail.gmail.com> (raw)


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Hi guys,


I am in a process of evaluating dm-cache for our backup system.

Currently I have an issue when restart the backup server. The server is
booting for hours, because of IO load. It seems is triggered a flush from
SSD disk (that is used for a cache device) to the raid controllers (they
are with slow SATA disks).
I have 10 cached logical volumes in *writethrough mode*, each with 2T of
data over 2 raid controllers. I use a single SSD disk for the cache.
The backup system is with lvm2-2.02.164-1 & kernel 4.4.30.


Do you have any ideas why such flush is triggered? In writethrough cache
mode we shouldn't have dirty blocks in the cache.


Thanks,
Alex

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             reply	other threads:[~2016-11-14 15:02 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-14 15:02 Alexander Pashaliyski [this message]
2016-11-14 15:34 ` dm-cache issue Zdenek Kabelac
2016-11-14 16:05   ` Alexander Pashaliyski
2016-11-15 12:38   ` Teodor Milkov
2016-11-16  9:24     ` Zdenek Kabelac
2016-11-16 13:45       ` Teodor Milkov
2016-11-16 14:06         ` Zdenek Kabelac
2016-11-19 17:07           ` Teodor Milkov
2016-12-02 19:49             ` Teodor Milkov
2016-11-15 19:57 ` John Stoffel

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