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Domain: baydel.com

Stories and comments across the archive that link to baydel.com.

Comments · 6

  1. Re:Can we let the old "write limits" go now? by Overzeetop · · Score: 3, Informative · on Alienware Puts 64GB Solid-State Drives In Desktops

    Well, I googled and came up with this: http://www.baydel.com/images/gallery/NAND%20flash%20resilience.pdf

    which is a whitepaper which shows a 64GB NAND device with a 100MB/s write speed can go for 20 years continuously, with error correction, before hitting the write limit. They didn't use the same numbers, but for a device with a likely lifetime of less than 5-6 years, they certainly seem to be up to practically any task.

  2. Here's a White Paper by Televiper2000 · · Score: 3, Informative · on Seagate to Offer Solid State Drives in 2008

    I did some poking around the net for information on NAND write cycles. They've already been quoted in the comments here (100,000 to 2,000,000) so I'm just going to post this neat white paper I found on Zeus drives that explains the endurance they get from their SSD Drive. http://www.baydel.com/images/gallery/NAND%20flash% 20resilience.pdf

  3. Re:Performance and Cost by MrChuck · · Score: 4, Informative · on DSI Delivers up to 3GB/s with Solid State Disk
    1. PCI @ 150MHz * 64bits is still 1200MB/s (that handwaves away any sort of overhead a bus might impose). So how are they getting 3036MB/s into a machine? Certainly not FCAL or SCSI. magic?
    2. When offered SSDs to work with for a project that needed lots of writes/reads of short lived files, I found them expensive, but good. I'm sorry to hear that Platypus ate it, I liked them and the idea of RAM on a PCI card - and they had linux and freebsd drivers. But SSDs COST a BUTTLOAD.
    3. I've used these guys' disks for years because they have tested to be as fast as SSDs. But with a half terrabyte behind them.

      With a battery backed cache of mirrored RAM, we found that for quick read/write stuff, the disks never got hit. If the data stayed, they ended up on the drives. If power was lost, the battery kept the cache alive for well over a day (I got bored and it met the "30 minutes" criteria we were looking at).

      The cache isn't huge (512? 256MB?) but it never filled. Basic elevator algorithms (we all did CS classes, right?) let the RAID side take data out of the cache in DISK order and write it out.

      And, not being Computer Vendor RAID, we found that it was fast and not expensive (given professional RAID). 15KRPM disks and dual controllers and dual PS and all that. Not for home use, but certainly for pro use. Oh and it gives great stats. Find stripe usage and cache hits on a Sun T3 that performs at half the speed for a good bit more money.

    I don't work for them, I just like their stuff. They're a small(ish) company that just does raid with lots of Wall St and corporate clients.
  4. RAID by MrChuck · · Score: 5, Informative · on Mac OS X 10.2.2 Update Available
    Hmmm, software raid ain't cutting it and ain't available for RAID 5 (and dearies, RAID 5 is out there, big time - a big win for my friend putting up about a terrabyte/week for their web server farm).

    What to do, what to do? /me strokes beard. Hey! How about using "A HARDWARE RAID!"

    Why waste your CPU cycles calculating stuff when you can have a dedicated processor taking care of your storage issues?

    Call your nearby raid vendor and get a box in. It speaks SCSI, it gives you lots of bonuses. Me? For high performance RAID at a decent price (too much for hobbyists and home users, don't waste your time), try these guys. Just a personal favorite, I'm not part of their company, just a customer.

    Why hardware RAID? When your MoBo/CPU/Disk dies and you can't get that software RAID reconfigured, you unplug the hardware RAID, plug it into a new machine and just go.

    When you want real speed, those baydel guys have a screaming, mirrored RAM cache so you get to write at 160MB/s.

    Jeez, you put all that money into your server and network connections and want to cheap out by using slow IDE disks and your CPU to do all the work?

    HFS+? Yeah, I still have it for my Mac Classic II on an 80MB drive.
    THanks, I'll use FFS with softupdates or ReiserFS (or XFS mmmmmm) on my real volumes.

  5. Re:Hot swap != big deal, multiproc & linux by cjs · · Score: 2 · on SGI's Linux Server

    the hardware must handle it, I mean, you must be able to add/remove a drive to a IDE bus/SCSI chain without everything going mad. Most hardware I met doesn't care if you remove a (umount'ed) drive.
    Well, if you want to do this reliably, you want a connector that's designed to deal with this properly. The standard SCSI SCA connector is a good example: It's not possible to misalign, there are no pins to bend, and the connectors mate in the appropriate order (ground first, then data, then power). This also requires some software support, since you really want to be doing this on a quiescent bus.

    If you want really good performance/reliability, go for RAID-5. Hardware support is not required anymore.
    Well, it's not required if you don't want really good performance and reliability with your RAID-5. :-) To do it properly, you need an external unit (such as a Baydel) that has a separate SCSI bus for each drive, so that a single drive can't lock the bus. Then you need two controllers on the Baydell, one for each of the two controllers on your host. Now you can lose any of the following and still stay up:
    • a drive
    • a RAID controller
    • a SCSI cable
    • a SCSI controller on the host
    Of course, on many machines you're still prone to motherboard failure at this point, which is why you're probably hooking this up to a Sun E-series box. Make sure the two SCSI controllers that the RAID box is hooked up to are on different I/O boards, so that if one I/O board dies, the other is still there. And of course make sure you have at least two separate CPU/Memory boards, so if one of those dies, the other is available.

    cjs

  6. Re:SGI IRIX has 4 of your weeknesses by cjs · · Score: 1 · on SGI open-sourcing XFS

    What happens if your raid card goes? Use software raid to mirror accross two controllers and you've eliminated a single point of failure.
    Buying a controller card with RAID built in is not typically how you'd set up a high-end server.

    Instead, you buy a box from someone like Baydel or Sun Storage Solutions. This box has a bunch of disk drives in it and a couple of controller boards that have SCSI controllers to talk to the disks, RAID hardware, and a SCSI controller to talk to the host. This disk box deals with all of the RAID stuff (striping, parity, rebuilding failed disks on hot spares, etc.). The host sees the entire array as one or more disks.

    For the host, you just buy a couple of regular SCSI controllers and plug each one of these into one of the controllers on the disk array box. Then you just have to set it up to fail over to the second controller if the first one fails in some way (be it the host controller, the cable, or the controller in the disk array box).

    cjs