![]() Timing cached reads: 2030 MB in 2.00 seconds = 1014.76 MB/sec Timing buffered disk reads: 232 MB in 3.00 seconds = 77.22 MB/sec Timing cached reads: 2066 MB in 2.00 seconds = 1033.49 MB/sec Let's see some performance, first single hdparm -tT /dev/sda Those disks are designed to have 8 hours/day life cycle and will probably die in two years. I don't really believe in desktop-grade disks, (even SATA). Why not simple striping over three disks (hack, I would get 500Gb of storage more)? Since I could fit just 4 disks in case, I will get 2 disks of accumulated performance and reliability (third disk). Having said this rand for RAID5, I also didn't want to boot from it (since I have system on 160Gb disk), and I just need reliable and fast disk. Much better performace (accumulated 4 disks) is just 5*RAID5. If you have enough disks (five for example) worst configuration is 2*RAID1 + 3*RAID5 since you get maximum of 2 disks accumulated performace. If you want to boot Linux from software RAID5 you are out of luck.īut there is simply no reason to install system on hardware RAID1 as opposed to hardware RAID5. And that's if you don't have hardware RAID5 which shows you RAID arrays as one disk anyway. Now, let's take a short de-tour and explain why do I want to have RAID5? Isn't RAID1 better/faster/right stuff for system? I wanted to use it just as SATA controller (with RAID part), so I was all set. I googled a bit and found some horror stories (including binary driver on Silicon Image's site for RHEL kernels), but latest Debian kernel 2.6.23-1-686 just worked. SiI 3132 Serial ATA Raid II Controller (rev 01) So, additional controller was in order, and only one which was available (with two SATA ports and in PCI-X variant) was no-name Sil 3132 based one:Ģ0:00.0 RAID bus controller: Silicon Image, Inc. I somehow assumed that I can connect more than one disk on one SATA channel, partly from SCSI world, partly from old IDE (err, PATA) master/slave relationship. Motherboard has just two SATA channels and form talking with a lot of people, it seems to me that SATA devices can't be chained (please correct me if I'm wrong). I wanted to add three more 500Gb disks in RAID5 array to create ~1TB storage with redundancy. I have Compaq brand-name desktop PC (refurbished, good buy) with one 160Gb SATA disk. My articles are more or less obsolete now, but this is short story of my RAID5 array for home. Several years after I wrote about software RAID1 and RAID5 I must say that I'm happily surprised how much software and hardware support for software RAID under Linux improved. ![]()
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