At 20:09 15/08/2002 +0800, you wrote: >Hi Nick, > >Thanks for your response > >At 10:52 AM 8/15/2002 +0100, you wrote: >>At 17:26 15/08/2002 +0800, you wrote: >>>Proposed setup :- >>>Hardware available >>>2 ATA133 hard discs >>>1 ATA100 hard disc >>> >>>1 ATA 133 hard disc connected to IDE (primary) slot of the motherboard >>>as MASTER as parity 1 & 2 (block 3 & 5) >>> >>>1 ATA 133 hard disc connected to IDE (primary) slot of the motherboard >>>as SLAVE as parity 3 & 4 (block 1 & 6) >>> >>>1 ATA '100' hard disc connected to secondary IDE slot of the motherboard >>>as MASTER as parity 5 & 6 (block 2 & 4) >>> >>>Will above connection be OK? If hard discs of different spec are used, >>>does it affect the RAID performance? >>> >>>Your advice would be appreciated. Thanks in advance >> >>A few points:- >> >>1) The array will be bottlenecked by the slowest drive. >>2) The total size of the arrays is dependant on the smallest drive. > >The 3 hard discs for this test are of 40G storage, 2M cache and 7,200 >rpm. One problem remains unsolved is my old motherboard used only >supporting ATA33.
You may run into bios limitations on an old board seeing drives of that size - I have two machines that will not see drives over 30G. Your mileage may vary... > I am considering using an available PCI RAID card (0, 1, 0+1), if > possible. Whether it can help??? That sounds a bit like a Promise chipset - we've never got raid-5 running on those. > Or I have to purchase a new ATA133 controller for this test. In such > case each hard disc can be connected to a separate slot. > >Kindly advise. That would be ideal and certainly a must for a production setup but if you are only experimenting and playing with the config files then your original setup will suffice as long as speed is not an issue. >>2) Running two drives on the same interface will cause severe performance >>degradation. >>3) The array with /boot on it must be raid0 or 1 - raid5 does not work >>for bootloaders. > >I recognize such a problem. In such a case could I use the PCI RAID card >to solve this problem, 2 ATA 133 hard discs connected to its slots (it has >2 slots) and the 3rd hard disc connected to primary IDE of the >motherboard. Its BIOS boots the PC at start. That sounds fine. As long as the RedHat installer sees three drives, you'll be OK. >It becomes Hardware RAID + Software RAID in one PC. Can it work? The only time I've seen something similar to what (I think) you mean is some onboard raid controllers needed to be told they were raid in order to boot, although redhat treated the devices as separate and therefore made a software raid on them. (??) >Have you had any comments? > >>4) This should be fine if you just want to experiment - there's a lot to >>work out with software >>raid when it comes to configuration files and testing for and replacing >>failed drives without >>losing data. >> >>I run software raid-5 pretty much everywhere so throw me a line if you >>feel the need. >>There's a software raid monitor tool at >>"ftp://ftp.nexnix.co.uk/pub/linux/scripts/mdmon"; >>if you should need it. > >Lot of thanks for your assistance offered. I will contact you to your >private email address and cc this list, if other subscribers don't mind >and if they expect to gain some experience on software RAID 5. cc to the list - no point in emailing me privately as I read the list anyway. That way others can join in and the dialogue will make it into the archives for later searches. >The software RAID monitor tool is only a perl script. How to use it ? Just modify the first couple of lines to reflect your email address (I really would rather not get your raid status reports.. :) ) and the network name of a Windows machine you want to receive pop-up alerts on, if you have one. Leave blank otherwise. Then either run it by hand, "./mdmon" or make an entry in your crontab for it:- # Check status of raid array hourly 0 * * * * /usr/local/cronjobs/mdmon 1>/dev/null 2>/dev/null >Thanks in advance. > >Stephen You're welcome, nick@nexnix -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/redhat-list
