On Tue, Feb 23, 2010 at 6:35 PM, Kam Leo <kam.leo@xxxxxxxxx> wrote: > Failing the "quick" test and long completion times are sure signs that > the drive is in trouble. You can try reformatting the drive to see if > that improves performance (doubtful). Good luck finding a new IDE > drive. You might have to use a SATA drive with a SATA-IDE adapter or > buy a SATA controller and change all your hard drives to SATA. Both SATA controllers and SATA drives are cheap and easy to find, and there are many, many advantages to SATA over parallel IDE. Didn't you say that the placement of drives in your case was constrained somehow? One of the most significant advantages of SATA - in fact the main reason we now use so many kinds of serial busses now, rather than the parallel busses of old, is that SATA cables can be quite long, and are thin and flexible. So you could put SATA drives anywhere you needed to and just get a long cable. An internal SATA to external eSATA adapter only costs ten bucks. With that and an eSATA enclosure for fifteen or twenty dollars, you could put your drives entirely outside your computer case. That's what I use for my two disk-to-disk backup drives: I leave one connected to eSATA and the other in a bank safe deposit box. Once a week I swap them. The bank is quite some ways from my home, so even a direct nuclear strike on my home office would not cause the loss of more than a week's worth of my work. SATA CD and DVD burners are quite cheap now. I bought a Pioneer Dual-Layer DVD burner for sixty bucks, that I think can now be had for forty. I recently bought a SATA Plextor Blu-ray burner, that can burn Dual-Layer Blu-rays that hold 50 GB. The unit only set me back I think $230. I intend to use that to make Blu-ray copies of my Disk-to-Disk backup drives, that will only require a few (but expensive) disks to hold my entire career's worth of data. A little over a year ago I bought four one-terabyte Western Digital RE3 (RAID Edition) drives for the AMCC 3ware 9690 RAID 5 in my F11 box. Those were really high end drives, yet only cost $200 apiece. Just your basic commodity drive, not a RAID Edition, would have similar capacity for about half the price. Finally SATA allows for better logical protocols, such as Tagged Command Queueing, which allows multiple I/O transfers to be issued in rapid succession, without having to wait for one to complete before issuing the next. With parallel IDE, the entire bus is completely tied up for the whole duration of a single command. There are lots of SATA controllers that support Linux these days. A two-port SATA Host Bus Adapter (HBA is the correct name, not "controller") would cost maybe twenty bucks. I have a couple four-port Promise SATA HBAs, and they have never given me any trouble. The HBAs can have from two to eight or so ports, and may have some internal ports and some external eSATA ports. eSATA is electrically identical to internal SATA; it just uses a different connector than the internal. SATA allows such long cables because it uses twisted pairs for each data channel, with differential signalling. Twisted pairs tend to cancel out electrical interference all by themselves, whereas differential signalling eliminates common-mode pickup. So a differential twisted pair cable can be quite long, and used in very, very electrically-noisy environments with no data transmission errors at all. Besides SATA, USB and FireWire use differential twisted pairs, as does Serial Attached SCSI (SAS). SAS uses the same cabling as SATA does, but with the SCSI logical protocol. The basic SATA uses the same logical protocol as parallel IDE, so much of the industry's existing investment into parallel IDE firmware and device drivers can still be used for SATA - one reason that it's so cheap. Please take my advice, my friend: the *last* thing you ever want to do is store valuable data on a hard drive that you're not completely confident of. While it is merely slow today, tomorrow it may start irretrievably losing data. You might not be able to tell right away that you have lost data, because you might not actually look at the corrupted files until much later on. (I've spent seven years doing all manner of storage programming. If there is one thing I know about, it is failed hard drives.) Don Quixote -- Don Quixote de la Mancha quixote@xxxxxxxxxxxxxxxx http://www.dulcineatech.com Dulcinea Technologies Corporation: Software of Elegance and Beauty. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
