From mboxrd@z Thu Jan 1 00:00:00 1970 From: dfc Subject: Re: USB chasis fails, fate of the software raid? Date: Thu, 19 Oct 2017 13:04:14 -0400 Message-ID: <1508432654.2579.5.camel@astro.cornell.edu> References: <1508353481.2692.9.camel@astro.cornell.edu> <17362074-5ca8-acc4-ab3b-0f5a41875416@grumpydevil.homelinux.org> <1508371578.2692.34.camel@astro.cornell.edu> <9158b8e4-5b1a-7e06-e19e-a30bcedba334@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <9158b8e4-5b1a-7e06-e19e-a30bcedba334@turmel.org> Sender: linux-raid-owner@vger.kernel.org To: Phil Turmel , Rudy Zijlstra , linux-raid@vger.kernel.org List-Id: linux-raid.ids Phil, Thanks for your comments below. On Wed, 2017-10-18 at 20:44 -0400, Phil Turmel wrote: > On 10/18/2017 08:06 PM, dfc wrote: > > On Wed, 2017-10-18 at 22:28 +0200, Rudy Zijlstra wrote: > > > USB is indeed not the best choice. > > Rudy, you master of understatement! > > > > > My main question is whether inserting the 5 disks into another  > > > > JBOD chasis is likely to work? > > > > > > Yes, this should work. With a little luck you would not even > > > need  > > > to force it, as with a component failure all disks should have > > > lost connection at the same time. > > I would be shocked if these disk *won't* assemble.  Assembly might > need > --force if any writes were in flight, but I doubt it. > > > > You could test each disk separately -- as long as you only read  > > > from them. Only reading is to ensure that no changes are done > > > that  > > > make later > > > > Thanks, I will try reading disks and then install in a new chasis. > > Just put them in a chassis and try to assemble.  If it succeeds, you > are > done.  If assembly fails, report what mdadm had to say. Will do > > > > re-build of the raid difficult. > > > > In particular is mdadm "smart enough" to find all the > > > > components  > > > > and/or do I need to do something to help it along? In fact, > > > > our  > > > > IT person has suggested that the data may well be lost. > > > > > > Your IT person apparently either thinks the HW failure caused  > > > extensive damage, or wants you to do something different, or... > > > is  > > > not very knowledgeable about this type of setup. > > Yeah, it does sound like somebody is out of their depth. > > > > > Also, since I first used the JBOD with software raid I came to  > > > > realize that the usb connection is not a good choice (though I  > > > > have never had problems). What sort of connection (at the low  > > > > price end of the market for HDD enclosures) would be better?  > > > > eSata or something else? > > > > > > eSATA would work. But depends on the type of enclusure you can > > > get. > > > I leave that to people based in USA, who know what is available > > > there. > > eSATA with a port multiplier should be fine.  It's spend a bit more > for > a JBOD with a SAS port and a suitable PCIe adapter. Thank you, I will hunt for JBOD+SAS. I need 5 or perhaps 6 disks in the array and am still searching for a suitable unit. David > > Phil > -- > 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