XPS9000 & RAID
in [Dell]
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From: Ben Myers on 14 Apr 2010 09:14 On 4/14/2010 12:51 AM, Tony Harding wrote: > On 04/13/10 14:00, William R. Walsh wrote: >> Hi! >> >>> I don't want to bet on the wrong thing here and lose 100's of GBs >>> of video, so I'm asking here for advice/help/whatever you've got >>> here. >> >> I think that you'd better make a backup before doing anything. >> Tinkering with RAID settings can be a data destructive process. > > "Can"? :) > >> You should expect the worst when "fakeraid" is in use. > > Good advice - backup's long since done. I tinkered with RAID about 3 yrs > ago with my XPS720 & XPS410 - dumped them both because I encountered > stability problems - a real no-no! > > Should I be looking at a "real" RAID controller, i.e., a card, if I'm > serious? RAID on the motherboard has gotten lots better, at least with an Intel-designed or -branded board. A couple of years ago, I did NOT assemble a RAID system for a customer who required near 24/7 access for stock trading. Recently, I DID do a RAID-1 system with an Intel DP55WB motherboard for a local graphic artist. System went together beautifully, RAID setup was simple, and the system runs and runs and runs 64-bit Win 7. If I had to make the transition from non-RAID to RAID-1, I would back up all data, then reinstall Windows from scratch... Ben Myers
From: William R. Walsh on 14 Apr 2010 10:27 Hi! > "Can"? :) I've heard that the Intel Matrix Storage manager tool tries not to destroy data if it doesn't have to. Seemingly some operations are supposed to be non-destructive. > Good advice - backup's long since done. I was worried, since you mentioned something about not wanting to lose video data. Extra disks are cheap -- I bought a Western Digital Green Power 2TB drive for about $140 shipped from Newegg yesterday. It's going to be in a FreeNAS box in another house. As the two places are within wireless network distance, I'm going to do a regular rsync from one FreeNAS to the other. Ever since a basement flood in 2004, I've been beating the drum about making better backups, with offsite capability, especially since all of my DDS tapes went under. I now have regular running backups on one FreeNAS box (made from an old HP Vectra Pentium Pro--probably the only PPro in the world with a SATA card in it!). Every month these get dumped off to an external disk that goes to a safety deposit box. > Should I be looking at a "real" RAID controller, i.e., a card, if > I'm serious? While many fakeraid solutions have improved (especially the Intel ones) I just don't trust 'em. One problem in particular stems from having the disk controller itself fail. Real RAID controllers deal with this by letting you back up the configuration to a file, which can later be restored to another controller board. So, yes, I'd definitely consider looking into a real hardware RAID controller. For basic arrays, I've used Adaptec's 3405 adapter and been very happy with it. It is a real hardware RAID controller with support for four SATA disks and many different RAID modes, including 0, 1, 5 and JBOD. The only drawback is that's not cheap. I also used to use the Adaptec 2410SA, and one is still under my control, running a RAID-5 array with a hot spare drive in a security camera recorder made from a PC. In the time that it's been up, two of the four disks have failed (each one at different times). Every time it has done just what it should--killed off the offending disk, switched to the hot spare and started rebuilding itself...even while 16 cameras worth of video were still pouring into the array. Or, if you don't want to do that, look into the software tricks that Windows can perform with disk based storage. It's possible to run software RAID on the operating system level with many versions of Windows. From what I've seen, this works fine and frequently does a LOT better than any fakeraid solution I've seen. William
From: William R. Walsh on 14 Apr 2010 10:30 Hi! > JMicron controls the eSATA port on the 9000. How interesting. It seems like a wasteful thing to do, and an unnecessary expense on Dell's part to have that extra controller. Unless of course they were worried about something zapping the controller by way of the external port and leaving all of the SATA ports dead. However, that does bring to mind another good point...even if the drivers were installed for the JMicron controller, it won't work to try and make an array from drives attached to two different controllers. (It would work if things were done on a higher level, such as in the operating system, using whatever concept it would have for software RAID. I still wouldn't want to chance it, though. Spanning a volume over two controllers sounds like a big risk to me!) William
From: Tony Harding on 14 Apr 2010 11:19
On 04/14/10 10:30, William R. Walsh wrote: > Hi! > >> JMicron controls the eSATA port on the 9000. > > How interesting. It seems like a wasteful thing to do, and an > unnecessary expense on Dell's part to have that extra controller. > Unless of course they were worried about something zapping the > controller by way of the external port and leaving all of the SATA > ports dead. > > However, that does bring to mind another good point...even if the > drivers were installed for the JMicron controller, it won't work to > try and make an array from drives attached to two different > controllers. (It would work if things were done on a higher level, > such as in the operating system, using whatever concept it would have > for software RAID. I still wouldn't want to chance it, though. > Spanning a volume over two controllers sounds like a big risk to me!) Agreed, but I wouldn't define an array including an eSATA HDD. |