HFS to ReiserFS conversion

[tillkrueger]

since i have 4TB of data that are on 1TB external USB drives (OSX HFS+ formatted), and need to copy that data over to unRAID, i was wondering whether it would be possible to use something like Acronis Disk Director to convert the disks to ReiserFS, then take them out of their enclosure, insert them into unRAID, do a "Restore" of the array (i am not using parity yet), and get the data into the pool that way?

 

just wondering...copying from the USB drives is painfully slow (about 10MB/sec), so it would take me another 6 days or so to copy it the same way i copied the current 4TB.

 

btw, how long will it roughly take to calculate parity on 8TB of data?

[Billped]

My five drive system with about 800GB of files took about two hours to calc parity.

 

 

Bill

[RobJ]

This sounds incredibly risky, if it's even doable.  I don't have a copy of Disk Director, but it seems very doubtful to me, that it could convert an HFS partition to a ReiserFS partition INPLACE!  The Reiser file system is rather different, and I suspect HFS may be too.  Besides, would it be accessing them while still in their USB enclosures?  Then you've got a 10MB/s read, perhaps an 8MB/s write back, giving an effective 4.5MB/s in the best case.  But because it's an inplace conversion and ReiserFS stores some things very differently, you'll have a certain amount of thrashing, probably resulting in about a 2MB/s overall conversion rate!  That 6 days becomes 30 days.  And worst of all to me, it just sounds way too risky, too many things could go wrong, and data would be lost.

 

Your fastest choice might be to find a LiveCD that has HFS support, and mount the drives in your unRAID server (all or one at a time), and use the LiveCD to copy the data to unRAID-formatted drives.  Failing that, then mount the drives in a machine that can read them, and copy the data over a gigabit network.  It *may* be a little faster than USB access.

 

[SSD]

Can't speak to the conversion issue.

 

The speed of building parity has a lot to do with how your drives are attached to your computer.  Drives attached to PCI add-on cards and certain motherboard ports use the PCI bus - with is only 66MHz.  It doesn't take many simultaneoius drives reading data at full speed to hit that limit.  If your drives are attached to motherboard ports (on most motherboards) or if you are using PCI-X or PCI-E SATA boards, then you won't hit this bottleneck, as least not as quickly.

 

If you have 8 TB drives  (+ parity = 9) and are using motherboard ports for 6 of them, I'd guess it'd take about 14 hours, maybe less.  That is just a SWAG at 20MB/sec on each drive.

[tillkrueger]

thanks guys.

 

Rob, you may be right...it could be risky while taking even longer...no point in doing that if your prognosis is even remotely accurate...i might just do what i have been doing and do the USB drives (connected to a server and shared via 1Gb LAN)...the bottleneck here is the bad USB implementation of the Western Digital MyBook Essential drives...they just can't do much more than about 10MB/sec...my LAN is capable of over 35MB/sec, sometime even more.

 

so, looking at Billped and bjp999's numbers, i'm looking at 14-20 hours...that's fine...i was worried it would be days.

 

you know, i was wondering about the PCI bandwidth bottlenecks, and was close to holding off on the mobo choice and Promise controllers because of that...as it stands, i use almost exactly what Tom uses as his MD-1500/LL:

 

> Lian-Li PC-A16B chassis with 15 removable hard drive trays

> PC Power & Cooling Silencer 610 EPS12V power supply

> ASUS P5B-VM DO motherboard with Dual Core E2180 and 2 GB DDR2-800 RAM

> 2 Promise SATA300 TX4 PCI controller cards

> 1GB USB2.0 Flash device (Cruzer) containing unRAID Server Pro OS

 

i have the first 6 drives and the parity drive hooked up to the mobo controllers, the other 8 drives are on the Promise controllers.

 

not to hijack my own thread, but does anyone know of a PCI-X based mobo that's known to work well with unRAID? i wouldn't be opposed to exchanging the ASUS for another mobo, exchange the Promise controllers for two Supermicro 8-port PCI-X controllers, and call it a day...i'd still want LG775, though...anyone?

[tillkrueger]

just as a follow-up:

 

thanks again Rob for keeping me from strolling down a dark path, trying to do an in-place file-system conversion.

 

as history had it, my DELL PowerEdge 840 Server arrived yesterday...they offered it for $499 last week, with an E2160, two 250GB SATA drives, 1GB of RAM, PCI-X, etc...i slapped my copy of Windows 2003 Server on it, hooked up my 1TB MyBook USB drives to it (after installing MacDrive, to HFS-enable Windows), and starting copying the data from my drives to the unRAID...low-and-behold, the data came across at between 20-30MB/sec, so i accused the USB chipset of the MyBook drives for no good reasons.

 

another great thing about having the DELL server with Windows 2003 Server on it is that i installed TVersity (a kick-ass, free UPnP server), mapped all my unRAID shares, and now i'm streaming and transcoding (in real-time!) my movies to any device in my studio...last night i watched Pink Floyd's Pulse DVD rip on my iPhone, streamed from the server...i know that i am insane, but still: yay!

 

3 more 1TB drives to go, then parity, then lean back and let it all sink in...what a great system unRAID is...thanks Tom!!!

[RobJ]

Excellent!