Once every few days, seemingly at random, our backup to an external USB hard disk fails on our hp DL380 G5 server running CentOS 6.4 64-bit. If I
cd /mnt/backup and run
ls it complains
ls: reading directory .: Input/output error, but
mount -l reports
/dev/sda1 on /mnt/backup type ext4 (rw). When I get someone on-site to check it out, they invariably report that the light on the external drive is slowly blinking, which is apparently normal for a sleep state. But I don't ask it to go into a sleep state until after rsnapshot runs, but rsnapshot causes my script to fail before that even has a chance to happen. Is it trying to save power? How can I get it to not do this?
/usr/bin/rsnapshot daily: ERROR: /mnt/backup/.snapshots does not exist.
Of course, if the person on-site unplugs and replugs the drive, I can remount it, and
.snapshots certainly does exist and rsnapshot will run without errors. For a while until the next random occurrance, that is. BTW, this is a pretty new WD Passport drive.
So how do I tell it to stay awake?