Is there an algorithm for sizing? Is it possible to have a disk that is too large? Is it possible to have a too many disks?
Regards Chris -----Original Message----- From: Igor Galić [mailto:[email protected]] Sent: Wednesday, December 14, 2011 4:14 PM To: [email protected] Subject: Re: Question about disk optimization in ATS. ----- Original Message ----- > > > > Thanks for the insight John. > > > > When you say no RAID of any kind – I was going to format 2 large > hardware raid 5 sets for redundancy. The raid 5 sets would be > comprised of 3 * 146GB SCSI drives (as there are two raid 5 sets there > are 6 disks in total). Are you saying that it would be best if I just > presented 6 (un-raided) disks to be formatted as raw disks? Yes. > Kind Regards > > > > Chris > > > > > From: John Plevyak [mailto:[email protected]] > Sent: Wednesday, December 14, 2011 4:04 PM > To: [email protected] > Subject: Re: Question about disk optimization in ATS. > > > > > > > > Under heavy forward proxy load, ATS tends to be seek limited which > favors lots of disks. As ATS has its own recovery mechanisms it is > best *not* to use raid5 or any raid, but just a bunch of raw disks > listed in the storage.config. > > > > > > ATS needs to have small block sizes, so don't use raid or stripe with > a volume manager as this will degrade performance. > > > > > > If you use a disk which has large blocks (3GB disk) then you may need > to set the flag to force ATS to use a larger internal blocks size > which results in some waste of disk space. > > > > > > If you are reverse proxy and have a small working set and a good size > RAM cache you may not be disk limited, in which case you have more > flexibility. Even in this case I would > > > still suggest not using raid or striping. > > > > > > john > > > > > On Wed, Dec 14, 2011 at 12:09 PM, James Chris Beaver < > [email protected] > wrote: > > > > > > Hello Folks, > > > > I am looking for information in regards to the best way to optimize > disk in ATS. I understand that the application uses raw disks however > what is the best way to lay out those disks? Is it best to have more > than one cache disk? I am inclined to put up more than one hardware > raid5 volume and then format them as raw disks for ATS to make use of. > Is there a “rule of thumb” when it comes to disk sizing? What block > size is best (large of small)? For example if you have to large of a > disk(s) will that slow down ATS as it must spend time keeping track of > very large caches? > > > > Any guidance is greatly appreciated. > > > > Regards > > > > -- > > Chris Beaver > > UNIX Systems Administrator, ITS - Algonquin College > > 1385 Woodroffe Ave > > Ottawa, ON K2G 1V8 > > email: [email protected] > > phone: (613) 727-4723 x 5385 > > fax: (613) 727-7719 > > > > > > > > > > > > -- Igor Galić Tel: +43 (0) 664 886 22 883 Mail: [email protected] URL: http://brainsware.org/ GPG: 6880 4155 74BD FD7C B515 2EA5 4B1D 9E08 A097 C9AE --
