From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Jes Sorensen <jes.sorensen@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
NeilBrown <neilb@suse.com>, Shaohua Li <shli@kernel.org>,
linux-raid@vger.kernel.org, neilb@suse.de
Subject: Re: RAID creation resync behaviors
Date: Tue, 09 May 2017 19:56:05 -0400 [thread overview]
Message-ID: <yq1y3u5potm.fsf@oracle.com> (raw)
In-Reply-To: <f73c7524-5d35-6104-11b1-2c658b43c68d@gmail.com> (Jes Sorensen's message of "Tue, 9 May 2017 17:22:57 -0400")
Jes,
>> BLKZEROOUT
>>
>
> Trying to read the code, as this ioctl doesn't seem to be documented
> anywhere I can find.... it looks like this ioctl zeroes out a device.
>
> It doesn't help me obtain the information I need to make a decision in
> mdadm as whether to overwrite all or compare+write when resyncing a RAID
> array.
I wasn't trying to solve your policy decision problem. I was merely
responding to Shaohua's concerns about discard vs. zeroes and wearing
out the media.
If you want to act based on the media type, the best heuristic we have
right now is the rotational sysfs attribute / BLKROTATIONAL ioctl. It'll
be one for spinning rust and zero for pretty much everything else.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2017-05-09 23:56 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-03 20:27 RAID creation resync behaviors Shaohua Li
2017-05-03 21:06 ` David Brown
2017-05-04 1:54 ` Shaohua Li
2017-05-04 7:37 ` David Brown
2017-05-04 16:02 ` Wols Lists
2017-05-04 21:57 ` NeilBrown
2017-05-05 6:46 ` David Brown
2017-05-04 15:50 ` Wols Lists
2017-05-04 22:00 ` NeilBrown
2017-05-03 23:58 ` Andreas Klauer
2017-05-04 2:22 ` Shaohua Li
2017-05-04 7:55 ` Andreas Klauer
2017-05-04 8:06 ` Roman Mamedov
2017-05-04 15:20 ` Brad Campbell
2017-05-04 1:07 ` NeilBrown
2017-05-04 2:04 ` Shaohua Li
2017-05-09 18:39 ` Jes Sorensen
2017-05-09 20:30 ` NeilBrown
2017-05-09 20:49 ` Jes Sorensen
2017-05-09 21:03 ` Martin K. Petersen
2017-05-09 21:11 ` Jes Sorensen
2017-05-09 21:16 ` Martin K. Petersen
2017-05-09 21:22 ` Jes Sorensen
2017-05-09 23:56 ` Martin K. Petersen [this message]
2017-05-10 5:58 ` Hannes Reinecke
2017-05-10 22:20 ` Martin K. Petersen
2017-05-10 17:30 ` Shaohua Li
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