[Harddrive] Newb Q

G

Gibe

Veteran XV
I went shopping for HD's today and saw a special on maxtor 250gb for $130. I heard/read/remember somehow/somewhere that my slave can only be seen as as big or smaller than the master. So:

1) How hard would it be to convert this master to a slave?
2) How would i do that?
 
so 250gb slave w/ a 120gb master is fine?

also will there be any problem w/ windows recognizing it as 250gb? im on XP pro.
 
mkay, ive got it installed successfully as a new slave storage drive but... it seems to be taking an EXTREMELY long amount of time to copy shit from one drive to another. Like 3 hours for 20gb. That's not normal is it?
 
uh... 3 hours for 20GB is not normal unless one of the drives is a piece of shit.

even at a lowly 30MB/s, you should be able to do all 20GB in 11 minutes. 15 at most.
 
I've noticed that I almost never get anywhere near the "rated" speed of a given hard disk, even for simple reads (writes are obviously even slower).

Some example hdparm info (configuration and tested speeds):

An old-ish IBM disk:
Code: 
# hdparm -I /dev/hda

/dev/hda:

ATA device, with non-removable media
        Model Number:       IBM-DJNA-371350
[...]
Configuration:
        device size with M = 1024*1024:       13042 MBytes
[b]        device size with M = 1000*1000:       13676 MBytes (13 GB)[/b]
Capabilities:
        [b]Buffer size: 1966.0kB[/b]   bytes avail on r/w long: 34     Queue depth: 32
        R/W multiple sector transfer: Max = 16  Current = 16
        DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 [b]*udma4[/b]
[...]
# hdparm -tT /dev/hda

/dev/hda:
 Timing buffer-cache reads:   652 MB in  2.01 seconds = 324.27 MB/sec
[b] Timing buffered disk reads:   52 MB in  3.05 seconds =  17.02 MB/sec[/b]

I'm relatively certain this is an IBM deskstar:
Code: 
# hdparm -I /dev/hdb

/dev/hdb:

ATA device, with non-removable media
        Model Number:       IC35L040AVER07-0
[...]
Configuration:
        device size with M = 1024*1024:       39266 MBytes
[b]        device size with M = 1000*1000:       41174 MBytes (41 GB)[/b]
Capabilities:
        bytes avail on r/w long: 40     Queue depth: 32
        R/W multiple sector transfer: Max = 16  Current = 16
        DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 [b]*udma5[/b]
[...]
# hdparm -tT /dev/hdb

/dev/hdb:
 Timing buffer-cache reads:   644 MB in  2.00 seconds = 321.41 MB/sec
[b] Timing buffered disk reads:  114 MB in  3.00 seconds =  37.94 MB/sec[/b]

And last, a Western Digital 200GB/8MB drive:
Code: 
# hdparm -I /dev/hdd

/dev/hdd:

ATA device, with non-removable media
        Model Number:       WDC WD2000JB-32FUA0
[...]
Configuration:
        device size with M = 1024*1024:      190782 MBytes
[b]        device size with M = 1000*1000:      200049 MBytes (200 GB)[/b]
[...]
Capabilities:
        bytes avail on r/w long: 74     Queue depth: 1
        R/W multiple sector transfer: Max = 16  Current = 16
        DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 [b]*udma5[/b]
[...]
# hdparm -tT /dev/hdd

/dev/hdd:
 Timing buffer-cache reads:   648 MB in  2.01 seconds = 322.92 MB/sec
[b] Timing buffered disk reads:  114 MB in  3.01 seconds =  37.90 MB/sec[/b]

Note that speeds will also be affected by:
1) Number of devices on a given ribbon
2) Activity of devices (if you're burning a CD, expect to see extremely slow transfer times on any hard disk on the same ribbon)
3) Whether you actually have DMA turned on
 
bo, i really don't trust hdparm very much but anyway, here:

Timing buffer-cache reads: 128 MB in 0.89 seconds =143.82 MB/sec
Timing buffered disk reads: 64 MB in 1.13 seconds = 56.64 MB/sec

That's on my 7200RPM 8MB buffer Maxtor 160GB.

But regardless, if you do the math to figure out how slow 20GB / 3 hours, it's actually about 1.85MB/s.
 
Yeah, i thought it was wierd because i can swap 3gb from my laptop to my master in about 5-10 minutes, but that would be about a half hour to just go from master to slave.

Both drives are Maxtor 7200rpm 8mb cache. the master is 120gb the slave is 250gb. They're both on the same IDE cable, which may or may not mean anything.
 
I think contention on the cable might be your problem. Information has to travel from the disk, down the cable to the DMA controller, then back down the cable to the target disk. The cable can only carry so much data at once (and only in one direction at a time), so data coming from 'source disk'->'DMA controller' is going to have to contend with data coming from 'DMA controller'->'target disk' for control of the transport medium.

Note that the above doesn't apply when copying to a device on a different cable.

Just my guess :shrug:
 
Bohica said:
I think contention on the cable might be your problem. Information has to travel from the disk, down the cable to the DMA controller, then back down the cable to the target disk. The cable can only carry so much data at once (and only in one direction at a time), so data coming from 'source disk'->'DMA controller' is going to have to contend with data coming from 'DMA controller'->'target disk' for control of the transport medium.

Note that the above doesn't apply when copying to a device on a different cable.

Just my guess :shrug:
Click to expand...
Thats what i thought might be happening.
KGB_ate_myBread said:
Are they on the same IDE cable? Is the master on the end of the IDE cable?
Click to expand...
Yes. Yes.

edit: if i switch the slave to a new ide cable and have it sharing a cd/dvd drive do i keep the slave jumper settings? or switch the jumper to master settings?
 
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