iDefrag for Mac OS X

elektro80 · Posted: Thu Aug 25, 2005 7:03 pm Post subject: iDefrag for Mac OS X

This is a pretty brilliant application.

http://www.coriolis-systems.com/
Product page

seraph · Posted: Fri Aug 26, 2005 12:00 am Post subject:

why did you post it here and not on the Apple forum?
do you use this application?

elektro80 · Posted: Fri Aug 26, 2005 1:25 am Post subject:

I cannot find the Apple forum.. So.. posted it here ..for now.

mosc · Posted: Fri Aug 26, 2005 5:09 am Post subject:

I don't mean to complain but his brings up something that is troublesome to me.

I think tools like disk defrag and optimizers should not be required. A good operating system should take care of the disk automatically. One thing about OSX that is annoying is that every time there is an OS update from Apple, the disk optimizer is run and the system reboots. On my PowerBook, this can take a long time (15 minutes).

elektro80 · Posted: Fri Aug 26, 2005 6:04 am Post subject:

mosc · Posted: Fri Aug 26, 2005 6:46 am Post subject:

You are right that earlier versions of Widows had severe problems that required defragmenting the disks frequently. I know one guy who uses Fruity Loops on Win 98 that defrags everytime before starting that program. Shocked

I've found XP Profressional to be amazingly robust. It is quite a different bird from earlier versions of Windows. I run for weeks without rebooting. I've never seen the infamous blue screen of death with XP - except the time I had a bad memory module. I have used the XP defragmenter program but have not seen any change in performance. So, I never use it.

I do run hardware RAID - disk mirroring. This is not expensive on an Intel platform. There are many motherboards that have RAID controllers. I use RAID 1/0. This provides both stripeing and mirroring. You get very fast reads because you can read from two disks simultaneously. and hardware redundancy too. This is very inexpensive; diisk drives are very cheap these days - everyone should consider this on a music workstation.

Hopefully, when Apple starts using Intel processors, they will put these RAID controller chips on their motherboards.

elektro80 · Posted: Fri Aug 26, 2005 7:25 am Post subject:

You get the same stuff for OS X too and OS X can set up software raids. No difference there. You could do RAID on macs years ago, even long before this was mainstream on PCs.

However, I don´t consider 0 and 1 to be even close to acceptable for DAW use. This is not about speed but stability and security. Raid level 5, hot spares, redundant PSUs and stuff like that. 0 and 1 can be just fine for serving files on a network too ( if those files are copies of stuff that is securedly stored on at least duped sets of tape and drives and whatever.) If the volumes die you can always fetch fresh files.

You can do level 50 too, but I am not sure I would do that on a DAW. A modern hardware based Level 5 RAID using 10.000 rpm SATA drives and fiberchannel for the connection to the computer should do just fine. This is expensive. There is a slight performance hit with level 5, but with modern fast disks this isn´t much of a problem anyway.

It might seem like madness that I am considering such gear, but I have some nasty projects coming up soon. Anyways, first I gotta finish those mixes and masters for Utmost Savagery and the PKD project volume 1.

Shocked

elektro80 · Posted: Fri Aug 26, 2005 7:28 am Post subject:

Well..hmm.. if the controllers are good and the drivers are good, then ordinary drive mirroring will provide excellent stability. Some of the better controllers offers hot spares and splitting and cloning of sets too.

mosc · Posted: Fri Aug 26, 2005 8:04 am Post subject:

elektro80 · Posted: Fri Aug 26, 2005 8:20 am Post subject:

Not really.

Level 0 -- Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.

Level 1 -- Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks.

if the implementation of level 1 provides splitting of sets then it s quite OK. You know.. if one drive dies you can establish a new mirrored set based on the remaining disk. Not all raid "products" out there can handle that 100%.

If you by 0/1 means 0+1 then we are looking at:
Level 0+1 – A Mirror of Stripes: Not one of the original RAID levels, two RAID 0 stripes are created, and a RAID 1 mirror is created over them. Used for both replicating and sharing data among disks.

I am a big fan of
Level 5.....----> Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.

... and HOT SPARES!!!!

elektro80 · Posted: Fri Aug 26, 2005 8:25 am Post subject:

mosc · Posted: Fri Aug 26, 2005 8:34 am Post subject:

Yes, I use 0+1, stripeing and mirroring, on my main DAW, and just RAID 0 on the other computers around here.

I've yet to loose a drive in a mirrored set. Laughing

There must be something to this, some version of Murphy's law. I was talking to a guy who runs an ISP server farm. He runns a lot of mirrored servers. He has never lost a server in a mirrored farm, but looses solo servers all the time. Shocked

Yikes, I better stop talking about these drives - they might hear me and fail. Twisted Evil