I thought some people here might find this amusing. After I quick-formatted a CD-RW with cdrwtool today I then did the following: mke2fs -b 2048 /dev/pktcdvd0 It appears to work OK and I'm compiling a kernel on it as I type this. pktcdvd can't handle this properly unless the '-b 2048' is given for a pretty obvious reason. df tells me that the capacity of a disc formatted like this is 530MB so there is a few MB lost compared to UDF. I'm pretty sure this is a follish thing to do so would anyone care to give me some technical reasons why? :) --John
On Mon, 6 May 2002, Johnathan Hicks wrote:
I thought some people here might find this amusing. After I quick-formatted a CD-RW with cdrwtool today I then did the following:
mke2fs -b 2048 /dev/pktcdvd0
It appears to work OK and I'm compiling a kernel on it as I type this. pktcdvd can't handle this properly unless the '-b 2048' is given for a pretty obvious reason. df tells me that the capacity of a disc formatted like this is 530MB so there is a few MB lost compared to UDF. I'm pretty sure this is a follish thing to do so would anyone care to give me some technical reasons why? :)
Yes, I have tested this too. It works in 2.4 but not in 2.5. In 2.5 sr.c complains about unaligned transfers when I try to mount the filesystem. 2.4 has code (sr_scatter_pad) to handle unaligned transfers, but that code was removed in 2.5, and I havn't yet investigated how it is supposed to work without that code. -- Peter Osterlund - petero2@telia.com http://w1.894.telia.com/~u89404340
On Tue, May 07 2002, Peter Osterlund wrote:
On Mon, 6 May 2002, Johnathan Hicks wrote:
I thought some people here might find this amusing. After I quick-formatted a CD-RW with cdrwtool today I then did the following:
mke2fs -b 2048 /dev/pktcdvd0
It appears to work OK and I'm compiling a kernel on it as I type this. pktcdvd can't handle this properly unless the '-b 2048' is given for a pretty obvious reason. df tells me that the capacity of a disc formatted like this is 530MB so there is a few MB lost compared to UDF. I'm pretty sure this is a follish thing to do so would anyone care to give me some technical reasons why? :)
Yes, I have tested this too. It works in 2.4 but not in 2.5. In 2.5 sr.c complains about unaligned transfers when I try to mount the filesystem. 2.4 has code (sr_scatter_pad) to handle unaligned transfers, but that code was removed in 2.5, and I havn't yet investigated how it is supposed to work without that code.
There's supposed to be a reblocking player in the middle, ala loop. This doesn't really work well for pktcdvd of course, so I'd suggest writing a helper for reading and writing sub-block size units. -- Jens Axboe
I've been playing stressing packet writing. First noticed that large files, eg linux source, never copied over ok. So I tried this: # cdrwtool -d /dev/scd1 -q # pktsetup /dev/pktcdvd0 /dev/scd1 # mount /dev/pktcdvd0 /mnt/cdram # tar jxf linux-2.4.18.tar.bz2 # find linux -type f -exec "md5sum" "{}" ";" >> /tmp/md5sums # tar jxf linux-2.4.18.tar.bz2 -C /mnt/cdram # (cd /mnt/cdram ; md5sum -c /tmp/md5sums) >> /tmp/results # cat /tmp/md5sums | wc -l 10006 # cat results | grep FAILED | wc -l 650 That's a 6.5% error rate. Any idea what's up??? I'm using packet-2.4.19-pre2 on linux-2.4.18, HP M820 portable CDRW and a PCMCIA scsi, Adaptec clone from Iomega. I'd been wanting to do large files for backups, and with LVM "snapshots" this could be fun! Thanks. Bill
Hello people Can anybody show me the way to speedup UDF writing of several directories with small files to CDRW disc? I have several books in html format. Size of many files not exceeds 15 Kbytes. During UDF writing pktcdvd first read block and then write it .. so resulting speed is too small ( ~ 10 Kb/s). Can pktcdvd module perform packet (64 K) composing using several small files? DirectCD 5.0 for Windows can work in such manner - there no read operation during writing to UDF media small files. Thanks. Regards, Sergiy Kudryk Ukranian LUG. P.S. I use kernel 2.4.18, IDE CDRW Mitsumi 4805 with scsi emulation __________________________________________________ Do You Yahoo!? Yahoo! Shopping - Mother's Day is May 12th! http://shopping.yahoo.com
On Mon, 6 May 2002, Johnathan Hicks wrote:
I thought some people here might find this amusing. After I quick-formatted a CD-RW with cdrwtool today I then did the following:
mke2fs -b 2048 /dev/pktcdvd0
It appears to work OK and I'm compiling a kernel on it as I type this.
This sounds very good because I would love to be able to format a dvdram in
ext2 format ... I will be following your lead ...THANKS
----- Original Message -----
From: "Peter Osterlund"
can't handle this properly unless the '-b 2048' is given for a pretty obvious reason. df tells me that the capacity of a disc formatted like this is 530MB so there is a few MB lost compared to UDF. I'm pretty sure this is a follish thing to do so would anyone care to give me some technical reasons why? :)
Yes, I have tested this too. It works in 2.4 but not in 2.5. In 2.5 sr.c complains about unaligned transfers when I try to mount the filesystem. 2.4 has code (sr_scatter_pad) to handle unaligned transfers, but that code was removed in 2.5, and I havn't yet investigated how it is supposed to work without that code.
-- Peter Osterlund - petero2@telia.com http://w1.894.telia.com/~u89404340
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participants (6)
-
Jens Axboe -
Johnathan Hicks -
Peter Osterlund -
Rochester Payne -
Sergiy Kudryk -
wbh