From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ram Ramesh Subject: Re: How important is SCTERC? Date: Sat, 29 Apr 2017 18:45:38 -0500 Message-ID: <64b80fbc-8ee9-c137-3da5-fffc563a7a6d@gmail.com> References: <48135126-cd8e-6321-77e6-06ae349ecc03@gmail.com> <22787.16039.574815.87299@tree.ty.sabi.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <22787.16039.574815.87299@tree.ty.sabi.co.uk> Sender: linux-raid-owner@vger.kernel.org To: Peter Grandi , Linux RAID List-Id: linux-raid.ids On 04/28/2017 08:07 AM, Peter Grandi wrote: >> [ ... ] I do run tler.sh that sets 180s timeout for drives >> that do not have scterc from /etc/rc.local. Am I putting my >> data in serious danger? > No. > >> I only have videos and tv recordings in this md > The problem with SCT/ERC absence is that the 2-3 minutes of > retries suspend IO for that long, and for people running > interactive applications (usually LAMP-style web applications) > that is a bad idea, but in your case you seem to have just a > personal archive of entertainment files. > > For interactive "enterprise" applications the common practice is > to reduce the error timeout to 1-2 seconds, so the failing drive > drops out of the MD set quickly and can be replaced, minimizing > delays. Interestingly, the drives did not pass SMART test and mkfs.ext4 -c -c checks. So, I returned them. I plan to buy WD gold (the other extreme in price point :-) > >> which can be replaced with significant effort (about 12TB of >> movies and tv shows will take some time to copy from my >> DVDs/BDs) > Backups are very important, and RAID is not an alternative to > backups. You can buy and use SMR disk drives as if they were > tapes (or with a filesystem like NILFS2) to do that backup, and > they are quite cheap. I am using my actual DVDs as backup. For TV shows they are available in Netflix, if I really want to watch them again. However, your point is well taken. I will think about backup as my collection has grown over the years and it will be really a pain to go back to DVDs to populate my media server. > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html