Re: SOLVED Re: vess raid stripes disappear
From: <hidden>
Date: 2013-05-10 12:44:11
Thanks for your reply. When I run the identical commands on the otherwise identical raid, stripes do get created and retained. But just to eliminate the possibility, I re-created a couple of stripes without setting the raid flag and once again, when the raid chassis was rebooted, they disappeared. I'm thinking at this point that it's a hardware problem with the RAID controller. Does that sound likely? On Fri, May 10, 2013 at 3:55 AM, Stan Hoeppner [off-list ref] wrote:
On 5/9/2013 6:29 AM, mashtin.bakir@gmail.com wrote:quoted
I have an interesting problem with a Vessraid 1830s. We have a few of these that work fine but one seems to lose its filesets. The only difference between the good ones and the bad one is that the bad one has firmware version 3.06 while the good ones are at 3.05 (This may not be relevant).It's not a firmware problem Mashtin. The problem here is incomplete education. More accurately, the problem is that you've confused concepts of hardware RAID and Linux software RAID. I will attempt to help you separate these so you understand the line in the sand separating the two.quoted
Here's what happens. If I plug the raid into a 32 bit RHEL5 box with large files enabled, syslog does pick it up: kernel: Vendor: Promise Model:VessRAID 1830s Rev: 0306 Type: Direct-Access ANSI SCSI revision: 05 SCSI device sdc:2929686528 2048-byte hdwr sectors (5999998 MB)The kernel sees a single 6TB SCSI device/LUN presented by the Promise array..quoted
Using the web gui, I can carve out partitions,The Promise web gui doesn't create partitions. That's the job of the operating system. What it does allow you to do is carve out multiple virtual drives from a single RAID set and export them as individual LUNs.quoted
I make three stripes across 4 disks of 2Terabytes each using RAID5.This is not possible with the Promise firmware. I think you're simply using incorrect terminology here. According to your dmesg output above you have created a single hardware RAID5 array of 4 disks, one 6TB virtual drive, and exported it as a single LUN. ...quoted
I then use gnu-parted (v3.1) to make the filesets:parted doesn't create "filesets". It creates partitions. What are "filesets"?quoted
mklabel gpt mkpart primray 0 0Ok so you created a primary partition.quoted
set 1 raid on^^^^^^^^^^^^^^^ THIS IS THE PROBLEM. "set 1 raid on" is used exclusively with Linux software RAID. What this does is tell the Kernel to look for a software RAID superblock on the partition and auto start the array. You are not using md/RAID, but hardware RAID, so the superblock doesn't exist. This is the source of your problem. This is where you have confused hardware and software RAID concepts.quoted
I create the fileset usingOk so when you say "fileset" you actually mean "file system".quoted
mkfs.ext3 -m0 /dev/sdc1 I can then mount the FS and write to it. If I either reboot the RAID or the host, the FS disappears ie cat/proc/partitions shows only sdc, not sdc1. If I go back into parted, the label is intact But I can't even mkfs without re-creating the label/partition, in wich case I get:This is a direct result of "set 1 raid on" as explained above. You should see other error messages in dmesg about no superblock being found.quoted
...Have been written, but we have been unable to inform the kernel of the change, probably because it/they are in use. As a result, the old partition(s) will remain in use. You should reboot now before making further changes. Ignore/Cancel? iClearing the parted RAID flag on the partition should fix your problem, assuming you haven't done anything else wonky WRT software RAID and this partition that hasn't been presented here. Always remember this: Any time your see "RAID" setup or configuration referenced in Linux documentation or cheat sheets on the web, it is invariably referring to a kernel software function, either md/RAID, dm-raid, etc. It is never referring to hardware RAID devices. If you have a hardware RAID device you will never configure anything RAID related in Linux, whether it be parted, grub, md, dm, etc. -- Stan