Raid configuration question
So, i've setup a file server with softraid rather than the older raidframe, however on the new system I tried setting my sd*b partitions to a raid 0 configuration so the swap space runs a little faster. After getting the swap space setup, though dmesg prints [ root on sd0a swap on sd0b ..]. After seeing this, i went ahead and setup a test system with raidframe again and built my raid on the swap partitions. Fstab points to raid partitions in both systems and they BOTH claim in dmesg that swap is being put on sd0b. My question is, am I getting somewhere with this or is the kernel going to look for sd0b and put swap on it automatically? Also, is there a way to prove the swap is on sd3b (softraid) or on raid0b (raidframe)? Zeb
Re: Raid configuration question
On Thu, Jul 07, 2011, Zeb Packard wrote: So, i've setup a file server with softraid rather than the older raidframe, however on the new system I tried setting my sd*b partitions to a raid 0 configuration so the swap space runs a little faster. After getting the swap space setup, though dmesg prints [ root on sd0a swap on sd0b ..]. After seeing this, i went ahead and setup a test system with raidframe again and built my raid on the swap partitions. Fstab points to raid partitions in both systems and they BOTH claim in dmesg that swap is being put on sd0b. My question is, am I getting somewhere with this or is the kernel going to look for sd0b and put swap on it automatically? Also, is there a way to prove the swap is on sd3b (softraid) or on raid0b (raidframe)? You should have provided disklabels, but let's read your mind. Do not stripe b partitions. 'b' is sacred, do not put other things on it. You should have striped the d/e/j paritions to create a softraid sd3, then disklabel that and use sd3b for swap. I really don't think striping swap is worthwhile however. Buy more memory.
Re: Raid configuration question
hmmkay, so both disklabels have an sd0b, softraid is pointed to sd3b for swap, but dmesg still prints 'swap on sd0b dump on sd0b' I'm assuming this is because sd0b is striped? I figure it's worth a shot on my test system, if it's quicker, I'm not opposed to the little bit of configuration up front. Thank you, Zeb
Re: Raid configuration question
On 07/07/11 18:02, Zeb Packard wrote: hmmkay, so both disklabels have an sd0b, softraid is pointed to sd3b for swap, but dmesg still prints 'swap on sd0b dump on sd0b' I'm assuming this is because sd0b is striped? no, it is because sd0b is swap BY DEFINITION. Do not use the 'a' partition of the first drive for anything but booting. Do not use the 'b' partition of the first drive for anything but swap. Do not use the 'c' partition of any drive. Do not forget there is a strong possibility that some day your first drive may no longer be your first drive, in which case some other drive's 'a' and 'b' will be spoken for. Respect that. If you have a [ws]d0b, it WILL be swap. If you promote sd1b to sd0b, whatever was on 'b' will become swap. IF you want to have swap on RAID, ok...don't create a 'b' partition on your real disks. Create a swap partition on your softraid disk, point to it with fstab. I figure it's worth a shot on my test system, if it's quicker, I'm not opposed to the little bit of configuration up front. it's a potential failure point. In a modern computer running typical applications, think of swap as your oh shit, that wasn't supposed to happen! recovery zone. In general, if you are optimizing your swap, you are Doing It Wrong. Special cases exist, I'm sure, but it is very much like cleaning the gun and polishing the bullets before putting a hole in your foot. The dirty gun and the tarnished bullet were going to do just fine. Nick.
