Re: How good is AMI MegaRAID support?
In my testing, I had 8x 18G LVD Quantum drives. With the same batch of drives, Vinum would deliver 35M/s reads and the AMI MegaRAID 1400 would deliver 14M/s reads. We're talking about a straight bonnie test, writing 5G files. The machine in question had 768M of RAM and the AMI 1400 had 64M of onboard (battery backed up) cache and was a PIII/450. I got the same results with both the Adaptec 2940U2W and the TekRAM-590F controllers. The battery-backed-up or not nature of the hardware RAID is immeterial to the "quality" of the system, BTW. The batter is neaded with the hardware solution because the PC doesn't know if the data has been written or not. In the Vinum case, the system knows what's been written and what's not ... (Then you have to start arguing about soft updates and other things --- it gets complicated... but done right you can have a few hundred megs of cache rather than 64) Dave. -- |David Gilbert, Velocet Communications. | Two things can only be | |Mail: [EMAIL PROTECTED] | equal if and only if they | |http://www.velocet.net/~dgilbert | are precisely opposite. | =GLO To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
Re: How good is AMI MegaRAID support?
At 1:19 PM -0400 2000/5/3, Charles N. Owens wrote: > Do you have any pointers to such information (ideally, something like a > "how-to")? Greg is the one who told me about it, and this was the kicker behind my finally getting off my butt and giving 4.0 a try, although I have yet to actually try to do anything with this particular functionality. > I do know that Greg Lehey has been investigating such functionality... Greg would be the man to ask. ;-) -- These are my opinions -- not to be taken as official Skynet policy == Brad Knowles, <[EMAIL PROTECTED]>|| Belgacom Skynet SA/NV Systems Architect, Mail/News/FTP/Proxy Admin || Rue Colonel Bourg, 124 Phone/Fax: +32-2-706.13.11/12.49 || B-1140 Brussels http://www.skynet.be || Belgium To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
Re: How good is AMI MegaRAID support?
Brad Knowles wrote: > At 1:55 AM -0400 2000/5/3, spork wrote: > > > Last I looked though, vinum cannot protect you from loss of your boot > > device. > > I am told that in FreeBSD 4.0, vinum now has the ability to > mirror the root filesystem. I don't know if this addresses the issue > you are concerned about, but I personally find it very interesting. Do you have any pointers to such information (ideally, something like a "how-to")? I do know that Greg Lehey has been investigating such functionality... Thanks, cno > > For some applications this may not be terribly important, but if > > you cannot afford to bring the machine down, the hardware solution starts > > to look better. > > I must admit that hardware does have certain advantages, but it > does require driver support from the OS (unless it's an external > SCSI-SCSI model), and I believe that the primary things you gain with > hardware RAID controllers is not performance but instead other > advantages, including transparency to the OS, etc > > If what you're after is absolute maximum speed for minimum money, > hardware is not the way to go. > > -- >These are my opinions -- not to be taken as official Skynet policy > == > Brad Knowles, <[EMAIL PROTECTED]>|| Belgacom Skynet SA/NV -- - Charles N. Owens Email: [EMAIL PROTECTED] http://www.enc.edu/~owensc Network & Systems Administrator Information Technology Services "Outside of a dog, a book is a man's Eastern Nazarene College best friend. Inside of a dog it's too dark to read." - Groucho Marx - To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
Re: How good is AMI MegaRAID support?
At 12:31 PM -0400 2000/4/29, Brandon D. Valentine wrote: > I can definitely appreciate that. The RAID solution of choice for > FreeBSD appears to be SCSI-SCSI RAID adapters as utilized on > wcarchive.cdrom.com and ftp.freesoftware.org -- the two busiest ftp > archives around and consequently the two busiest disk subsystems around. The testing I've done so far confirms what Greg Lehey and everyone else has been telling me all this time -- dedicated RAID controllers just really can't keep up with a good software solution (such as vinum, or even ccd) and modern hardware. It takes a lot longer to develop all the custom hardware to put into a RAID controller, and main CPU speeds have been increasing so fast, that it's quicker and easier to do it all in software these days. Even the megabuck Comparex/Hitachi mainframe-style RAID array that I've been pounding the snot out of for weeks doesn't reach the performance levels of the software RAID configuration that Joe Greco built on top of Adaptec controller and bare 50GB 7200 RPM drives (for his 1.8TB news spool server), and I have 10kRPM drives and can throw as much as 4GB of on-board controller RAM at the problem. I can get reasonably close to his levels of performance, but I haven't been able to equal them. In fact, to come anywhere *close* to the levels of performance that Joe has previously mentioned, I've had to add software RAID 0+1 (in the form of vinum) on top of the hardware RAID-5 (we tested the other forms of RAID, there doesn't seem to be any noticeable speed improvement), so that you are striped both horizontally and vertically. -- These are my opinions -- not to be taken as official Skynet policy == Brad Knowles, <[EMAIL PROTECTED]>|| Belgacom Skynet SA/NV Systems Architect, Mail/News/FTP/Proxy Admin || Rue Colonel Bourg, 124 Phone/Fax: +32-2-706.13.11/12.49 || B-1140 Brussels http://www.skynet.be || Belgium To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
Re: How good is AMI MegaRAID support?
> > - Original Message - > From: "Mike Smith" <[EMAIL PROTECTED]> > > | If that's what they say, I'd be inclined to believe them. Since I've > not > | encountered any fatal problems with the 2.x firmware, I can't suggest > | that upgrading would actually win you very much. > > I'm not even sure the HPDA flavor of cards is supported by FreeBSD to > begin with. I hooked up my HPDA DAC960PL to a 4.0-STABLE box (cvsup'd > last night) today and during bootup I get: > > mlx0: port 0xdc80-0xdcff irq 11 at > device 13.0 on pci0 > mlx0: couldn't allocate mailbox window > device_probe_and_attach: mlx0 attach returned 6 What firmware revision are you running? This looks like your card isn't supporting a memory-mapped region for the mailbox window - I should check for this I guess. I'm fairly sure that 2.42 or later will work. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ [EMAIL PROTECTED] \\ and he'll hate you for a lifetime. \\ [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
Re: How good is AMI MegaRAID support?
> On Sat, 29 Apr 2000 13:13:37 PDT, Mike Smith wrote: > > > >You leave out "how well you want it to perform" as well. All other > >things being equal, the PCI:SCSI adapters will give you better bang for > >your buck. > > Out of curiosity, how would a PCI-RAID (SCSI) adapter compare with > vanilla PCI-SCSI cards and vinum? It seems to me that the host CPU(s) > are much faster than the processors on the PCI-SCSI adapters. Or are > both of these "fast-enough" and thus performance differences are largely > an irrelevent consideration? (They both have similar software issues > but I suspect vinum is easier to debug. :) All other things being equal, software RAID is going to be faster. (ie. same disks, same # of SCSI channels, etc.) The hardware solution's sell there is: - better support/functionality (enclosure management, etc.) - better survivability (battery-backed cache) Plus you get a stack of SCSI channels onboard the card. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ [EMAIL PROTECTED] \\ and he'll hate you for a lifetime. \\ [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
Re: How good is AMI MegaRAID support?
- Original Message - From: "Mike Smith" <[EMAIL PROTECTED]> | If that's what they say, I'd be inclined to believe them. Since I've not | encountered any fatal problems with the 2.x firmware, I can't suggest | that upgrading would actually win you very much. I'm not even sure the HPDA flavor of cards is supported by FreeBSD to begin with. I hooked up my HPDA DAC960PL to a 4.0-STABLE box (cvsup'd last night) today and during bootup I get: mlx0: port 0xdc80-0xdcff irq 11 at device 13.0 on pci0 mlx0: couldn't allocate mailbox window device_probe_and_attach: mlx0 attach returned 6 The card and cable are good, they were last used with Win2K about two weeks ago. The disk cabinet (an HP "Disk Array" 5x1GB) I'm not sure about, though. When trying to initialize the array with Jetset, the HP DOS tool, and it just hangs there trying to do an inquiry on the drives. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-stable" in the body of the message
