On 07/08/2020 15:47, Haines Brown wrote:
Cron automatiically backs up some partitions on my HD by means of a
script. Not sure of the size of thse backupos, but perhaps 300 Mb.
I have been doing the backups to an external WD USB drive, and they
took around 3 hours. However, I became nervous about the condition of
the drive which is quite old, and so bought a 2 Tb replacement. Now
the back up takes 10 hours.
The only thing that I can think of that might account for its being
slow is that my old WD drive was formatted ext4, but I thought best to
leave my new drive with NTFS.
This causes a problem in that if the backup drive happens to be
mounted, the mount command in my script no longer just tells me so
and proceeds with the backup, but instead hangs.
The other problem may be that for some reason the disk being NTFS
drastically slows the backup. So it occurred to me to make the command
in the script to mount the drive: mount -t ntfs /mnt/backup (I have
the drive's UUID in fstab). But when I check /proc/filesystems, ntfs
apparently is not recognized by the kernel. However, my impression
is that my having the ntfs-3g rw driver installed should enable me to
mount a NTFS partion wtihout problem or need for the -t ntfs option.
I checked my CPU instuctions/second. The services started at bootime
have not changed. The # top command does not show any problems. $ free
suggests I'm not demanding too much of my RAM. # iotop shows that my
backup process I/O demand on the kernel runs 50-100%. The kworker
flush can be 100%. My guess is that these figures are to be expected.
I run the backup at a time when no other significant processes are
running.
Do you use the USB drive on Windows, if not, just reformat it to ext4,
ntfs-3g is a FUSE system, it isn't a fast as you would like.
Rowland
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