From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Fjellstrom Subject: Re: recommended way to add ssd cache to mdraid array Date: Mon, 14 Jan 2013 15:00:49 -0700 Message-ID: <201301141500.49197.thomas@fjellstrom.ca> References: <201212212357.19292.thomas@fjellstrom.ca> <9974543B-24D0-46E9-9852-09DE1C2F6D12@colorremedies.com> <50F3501B.30002@turmel.org> Reply-To: thomas@fjellstrom.ca Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50F3501B.30002@turmel.org> Sender: linux-raid-owner@vger.kernel.org To: Phil Turmel Cc: Chris Murphy , linux-raid Raid List-Id: linux-raid.ids On Sun Jan 13, 2013, Phil Turmel wrote: > On 01/13/2013 06:20 PM, Chris Murphy wrote: [snip] > >> One last point bears repeating: MD is *not* a backup system, > >> although some people leverage it's features for rotating off-site > >> backup disks. Raid arrays are all about *uptime*. They will not > >> save you from accidental deletion or other operator errors. They > >> will not save you if your office burns down. You need a separate > >> backup system for critical files. > > > > Yeah and that's why I'm sorta leery of this RAID 6 setup in the home. > > I think that people are reading that the odds of an array failure > > with RAID 5 are so high that they are better off adding one more > > drive for dual-parity, and *still* not having a real backup and > > restore plan. As if the RAID 6 is the faux-backup plan. > > > > Some home NAS's, with BluRay vids, are so big that people just either > > need to stop such behavior, or get a used LTO 2 or 3 drive for their > > gargantuous backups. > > Well, for me, such material on hard drives *are* the backups. I use > "par2" for big backup files, not MD raid. I also skip backups for my > Hi-Def MythTV recordings. Just not valuable enough. Yeah, I learned a while back to make proper backups. My very important files are backed up from each machine every day to a raid1, which is then synced up to a remote machine. Once the new array is up, the backups will have another location to copy to, as well as the not so important media files will have a backup (some 3TB drives and a few of the old 1TB drives in a linear concat 'array'). I may add another remote backup location in the future, I just haven't decided who to go with. > Phil > -- -- Thomas Fjellstrom thomas@fjellstrom.ca