# External USB drive issues



## gkontos (Jun 4, 2011)

I use an external Seagate USB drive to send incremental snapshots of my data.

```
Jun  4 13:29:51 hp kernel: da0: <Seagate FreeAgent Go 0138> Fixed Direct Access SCSI-4 device 
Jun  4 13:29:51 hp kernel: da0: 40.000MB/s transfers
Jun  4 13:29:51 hp kernel: da0: 610480MB (1250263726 512 byte sectors: 255H 63S/T 77825C)
```
I know it is not the perfect solution but it does its job. The problem:

It appears that the drive decides to go to sleep after some period of inactivity. Causing issues like those:

```
Jun  4 04:17:11 hp root: ZFS: checksum mismatch, zpool=zbackup path=/dev/da0 offset=416888403456 size=512
```
What I usually do to avoid this kind of problem is to import the pool before I send the snapshots and then immediately export it. But this is a cheap workaround and it kind of beats the purpose of automated backup. So, I am looking for a command to run as a cron job maybe, that can query the drive every now and then in order to wake up from its deep sleep!

Any suggestions are very welcomed.


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## gkontos (Jun 15, 2011)

http://seagate.custkb.com/seagate/crm/selfservice/search.jsp?DocId=214217&NewLang=en&Hilite=

But unfortunately it has to be done from windows.


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