Running rman with virtual tape speed too low(500KB/s approx)

Question

Hey guys, I run rman with mhvtl. but the backup speed is too low(500kB/s).
the mhvtl debugging prints indicate that the block size is 64kB and the scsi command is running synchronous.
does any one know how to speed up this backup operation?<smiley image='anim_crazy.gif'/>
Thanks.
<b>my system:</b>
linux kernel 2.6.18
mhvtl 0.18.17
oracle10
obtool 10.2
<b>rman configure:</b>
RMAN> show all;
using target database control file instead of recovery catalog
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO 'SBT_TAPE';
CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/backup1/ctl_%F';
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE SBT_TAPE TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
CONFIGURE DEVICE TYPE 'SBT_TAPE' BACKUP TYPE TO BACKUPSET PARALLELISM 1;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE CHANNEL 1 DEVICE TYPE DISK FORMAT '/backup1/backup_%U';
CONFIGURE CHANNEL 2 DEVICE TYPE DISK FORMAT '/backup2/backup_%U';
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' MAXOPENFILES 1 PARMS '';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/home/oracle/oracle/product/10.2.0/db_1/dbs/snapcf_orcl.f'; # default

Answer 1

skoczo wrote:What services could i disable?
anything you don't need at startup.
If you disable systemd service from startup, you will lose some kind of functionality, and you should try to figure out yourself whether you need that functionality of not.
If you use pulseaudio (I assume you do, since it looks like you're using gnome), you can safely disable alsa-restore.service and alsa-store.service, as pulseaudio will restore audio levels by itself.
I've masked systemd-vconsole-setup.service myself (disabling isn't enought), since I rarely use virtual console on ttys. I don't have correct keymap on ttys but that's not a big deal for me.
I don't think you need all those @backlight services either. I've personally masked all but one on my system.
e4rat will most likely reduce your start up time greatly, although it's a bit of a hassle to set up.
systemd-readahead might also help, but you should test it for yourself.
I'm also thinking you could probably optimize your initramfs a bit, as 11s is quite long for loading kernel. At least make sure you have 'autodetect' hook enabled in mkinitcpio.conf.
Also you can use lz4hc for compressing initramfs (COMPRESSION="lz4" and COMPRESSION_OPTIONS="-9" in mkinitcpio.conf), which should be faster on decompression than other algorithms.
There are some more tips in arch wiki, if you didn't check it out already