my client had this server for Oracle database, the server had 2 RAID array (RAID 1 and RAID 5). the Linux sys admin configure the box with 2 SWAP file: the first one is 2ghz running on RAId 1 and the second one 2ghz running on RAID5.

1. why did you configure 2 SWAP file??? Pros and conc????

2. if he configure the SWAP file on RAID 5, will there be performance issue since it had to do the mirroring????


thanks

At times usually if you find two swap partitions or files, the second one was added at a later time cause it was needed maybe under heavy load, etc. Having a swap file not doing nothing is harmless though. If its not being used and hasn't been used, get rid of it or just leave it be.

thanks

could you please answer my second question????

Sorry about that, totally missed it in my reply.. but there shouldn't be a performance issue. But if I'm understanding your correctly, you shouldn't need to mirror a swap partition in a raid setup but again, shouldn't be using that much swap in the first place.

Thanks Tricky,

Sorry to bug you again. more question since I would like to understand this process. So you are saying I shouldn't mirror a SWAP partition in the RAId set setup, how????


1. If you have let's say the total of 6 physical disk: two of them on RAID 1 and the other four on RAID 5 so where is the space left so you can put the SWAP file except for the partition on RAID 1

2. assume if possible to SWAP file on the no RAID array, what if the disk are gone and you lost the SWAP file, what will happen????


so if some of my question are silly b/c I am trying to learn and understand Linux

1. I'd put it on the first disks using RAID 1 most likely, create its own partition but again, it won't hurt to mirror it either. I just don't find it necessary to mirror raw data that would almost be pointless to keep if one disk failed.. swap is like memory, you reboot and that data is gone anyways..

2. Losing swap will usually never bring your system down. In most cases, you want to avoid trying to use swap. Depending on what the server is doing, if you find that your always using swap, your probably better off upgrading and adding more RAM to the machine.

great, thanks million