Pioneer DVR 107 and IDE configuration

vbimport

#1

I am adding the Pioneer DVR107 to my system. I currently have
a dvd drive, cd-r/rw, and the boot drive, as well as 3 hard drives for storage. (Yes, I can have up to 8 IDE devices) Should the 2 dvd optical drives be on the same (secondary) IDE channel, the dvd burner as master and the dvd rom as slave, then the hard drive (boot) and the cdrw drive on the primary IDE channel?
If so, on the primary channel, should the boot drive be master or slave? Maybe I have too much in the box…:slight_smile:

What’s in the box?
Win XP Pro SP1
Antec 1040 SOHO Tower
Gigabyte GA8PE667 Ultra mobo/P4 2.8ghz
1024 mb PC2700 RAM
Cendyne Lightning4 CD-RW
16x DVD Rom
80gb 7200 RPM hd (boot)
2x60gb 7200 hd (storage, RAID 1)


#2

The key thing to remember with IDE configurations is that the computer can’t access two drives on the same channel simultaneously. Once a request is outstanding on one drive, the other drive on that channel is inaccessible. This is an architectural limitation of IDE compared to SCSI (and one reason why SATA has gone with a ‘one drive per channel’ approach - all SATA drives are masters).

There are apparently still some situations where certain drives don’t like to be slaves - but I’ve never come across one recently.

My personal rules for IDE configuration are that a hard disk has a channel to itself, and that optical drives can share. The qualification with optical drives sharing a channel is that you may hit problems trying to use both at once - so if a reader and a writer share, you may struggle to copy disc to disc between the two (though these days most programs go via the hard disk), and if the drives are two writers, you may struggle to use both simultaneously.

However, there’s no hard and fast rules - you may find that combinations that are theoretically sub-optimal for performance work fine in practice. For example, unless two hard disks are accessed heavily and, more importantly, simultaneously (as they would be in a RAID setup), you can probably get away with two hard disks sharing, though I would try to avoid it. After all, most hard disk accesses, particularly when streaming data, are over in a few milliseconds. Optical drive accesses, particularly when burning, can be rather longer, which can lead to problems if you are trying to access (and especially burn from) a hard disk on the same channel as the writer. Even then, such a combination may work.

Two hard disks involved in a RAID on the same channel could well be a performance hit. Are your storage pair really RAID 1 (mirroring)?

Anything else is really experimentation, and the best setup may depend on how you use your system. Personally wouldn’t want anything optical (and especially a writer) on the same channel as my boot drive, especially if it contains the Windows swap file.

I’m fortunate really - in my seven drive setup, two hard discs are U320 SCSI, the tape drive is U2W SCSI and the CD-RW is Ultra SCSI. That lot is across two SCSI controllers - the LSIlogic U320 SCSI controller on my motherboard controls the hard disks and tape drive.

The CD-RW is on an Adaptec 2920C Fast-10 SCSI PCI card with my scanner. Fast-10 is more than fast enough, and my 29160N U160 SCSI card doesn’t work properly under Windows XP - thanks a lot Adaptec - I have the choice of Microsoft drivers that tend to leave all narrow devices operating in asynchronous mode which makes the CD-RW unusable as a writer, or Adaptec drivers that hang Windows at logon if the scanner is attached (you usually finish up with a controller error in the System Event Log if Windows doesn’t crash utterly before it gets that far). I might look for an Ultra SCSI card like an Adaptec 2940AU on eBay.

That leaves my slowest hard disk (only used for backup to disc and as a scratch space) and two other optical drives as IDE. The hard disk is primary master, the two optical drives share the secondary channel.

David


#3

<<Two hard disks involved in a RAID on the same channel could well be a performance hit. Are your storage pair really RAID 1 (mirroring)? >>

Yes, they are indeed mirrored. But they do not share the same channel–one is on IDE3 and the other on IDE4. I do not want to add anything to this array which would interfere. I have this set up this way because I can be too lazy to back up on a regular basis, and the odds of both hard drives crashing at the same time is remote. This may have to change, depending on how things work out on the primary/secondary channels once the drive arrives. Thanks for your answer.


#4

Sure - I understand. RAID 1 does produce a read performance enhancement too. It’s entirely correct that the pair are on two different channels.

I’m sure you understand that even with RAID 1 pair, there’s several single points of failure remaining. In particular, a power supply failure could disable both drives, as could any kind of crash that causes disk corruption (rare with NTFS, I know, but I have had one spectacular crash on Windows 2000 on an older machine that utterly corrupted the C: partition and had me reaching for the backup tapes).

Still, you have more robustness than with a JBOD (Just a Bunch Of Discs) setup.

I make use of nightly backup to disk on my system. There’s a 7200rpm 160GB IDE disk in my otherwise all 15000rpm U320 SCSI HD setup that’s used almost exclusively for backup storage. The system runs weekly full backups and daily differential backups - I keep three weeks worth on the hard disk and four weeks worth on tape.

Once the automatic backup to disk completes, the backup software continues on copying the backup set to DDS-4 tape. That, however, is not a cheap backup system - neither for the hardware nor software (VERITAS Backup Exec for Windows Servers 9.1) involved.

I know very well that a backup procedure that’s difficult doesn’t get done.

I hope that the original answer was useful.

David