Re: Disk Storage

Steve Romankiw wrote: > > Early next year, I will begin a project of evaluating disk storage > solutions. This includes solutions from Sun, EMC, and IBM to name a > few. > > My current environment consists of 3 Sun Ultra E4000's (Solaris 2.5.1) > connected to 3 Sun SSA model 1xx series. We use Veritas Volume 2.4 as > our volume manager. > > To get a discussion started, I have a few questions: > > o What storage solution are using? We use both EMC and DG Clariion. We tend to favor Clariion because of price and support except where absolute performance is required. We are also testing Sun's newest high speed disk subsystems. > o How did you evaluate each vendor? DG is much more responsive to user needs and problems. EMC seems to feel "We know what we are doing and what you need MUCH better than you do!" Good product bad attitude. > o Why did you choose one vendor over the other? Technical Reasons or > company synergy? We consider cost, features, performance, & support. > o How do you provide for high-availability? e.g, what happens when > your storge unit fails. For filesystems we use RAID5 for Informix RAW partitions I ONLY use RAID1+0 (ie a stripe of mirrored pairs). > o Does your storage system require proprietary drives or can you use > "off-the-shelf" drives? EMC uses proprietary drives, Sun uses off the shelf drives and DG uses off the shelf drives but formats them with an odd blocksize (520bytes) so it is usually easier to get preformatted drives from them. DG drive prices are reasonable (about 1/2 EMC and about 10% higher than generic). > o Was Host-based vs. Controller-based RAID important to your > decision? Controller based RAID tends to be faster but lacks flexibility like being able to build RAID1+0 with mirrored pairs on separate controllers and power supplies. > o Does your storage unit connect to UNIX, NT, or Netware? UNIX. Solaris and DG/UX. > > Thanks for your input... You are welcome. Art S. Kagel PS - Tip of the day: Veritas will let you specify different RAID block sizes for different zones on the drives. With today's zoned disks having vastly different numbers of sectors per track in different zones this is significant. You can improve throughput up to 30% by zoning the RAID/Stripe block sizes. To do this you have to get drives from vendors that are willing to tell you their zoning rules (Seagate flatly refuses for example).