Re: DLT Backup/Restore Speed
From: Bill Vermillion (bv_at_wjv.com)
Date: 12/30/04
- Next message: NSM: "Re: DLT Backup/Restore Speed"
- Previous message: NSM: "Re: DLT Backup/Restore Speed"
- In reply to: NSM: "Re: DLT Backup/Restore Speed"
- Next in thread: NSM: "Re: DLT Backup/Restore Speed"
- Reply: NSM: "Re: DLT Backup/Restore Speed"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Date: Thu, 30 Dec 2004 06:35:04 GMT
In article <PwMAd.35269$dv1.33864@edtnps89>, NSM <nowrite@to.me> wrote:
>
>"JP" <NO_SPAM_PLEASE_pangjo@netzero.com> wrote in message
>news:FfOdnbf5me1bDU7cRVn-pQ@rogers.com...
>| We found the speed for backup and restore quite slow on the HP Netserver
>| LH3000 runnign SCO 5.0.6. The tape drive is an HP SCSI-3 DLT 40/80
>| connected to an Adaptec Ultra 160 controller.
>|
>| To backup and verify 70GB of data on the RAID (0+1) drive, it took 7
>hours.
>| Just to restore 2 files of 100MB each this afternoon, it took 2 hours
>each.
>| When compared with the performance of the backup/restore on another
>Windows
>| server, it is very hard to justify the slow speed. I can restore a 100MB
>| file in just 15 minutes using BackupExec.
>|
>| I am not sure it is the right speed for our tape storage on the SCO. We
>are
>| running BackupEdge version 01.0.08, build edgesco5.01.01.08. Here is the
>| configuration of the tape:
>|
>| Device Nake: dev/rStp0
>| Compression: Hard
>| Tape Block: N/A
>| Edge Block: 64
>| Partition: C
>| Can someone tell me if this is the right speed or something can be done to
>| improve the speed? Thanks in advance.
>It wouldn't surprise me in general on a SCO system but it is
>slow. The restore is not unusual either, since you have to go
>serially through the tape. Do you need the compression on?
The SCO file system shouldn't be that slow. I've measured it
against others and it's slower.
He's getting 70MB backup and verify in 7 hours. The speeds he's
getting seem more like I'd expect of a DAT and not a DLT.
What he did not report are the speeds which are reported in the
reports of BE - it will show the time for backup and how long it
takes to verify. Also missing are the make and model number of
the HD's - as that can have a huge impact on speed. You really
need to go to the manufacturers site and look at the tech specs
for the speed of data transfer from media to the buffer.
I've seen a drive with a slower rotational speed have higher
data throughput - usually because of superior head design.
If he's performing bit-level verify I've noted that is about
twice as long as backup as it has to read HD and tape.
Running with hardware compression will actually be faster than
running without it, as the drive can accept data from the machine
at up to two times the rate it will with non-compression. And the
HW compression in tape drives is very fast.
Bill
-- Bill Vermillion - bv @ wjv . com
- Next message: NSM: "Re: DLT Backup/Restore Speed"
- Previous message: NSM: "Re: DLT Backup/Restore Speed"
- In reply to: NSM: "Re: DLT Backup/Restore Speed"
- Next in thread: NSM: "Re: DLT Backup/Restore Speed"
- Reply: NSM: "Re: DLT Backup/Restore Speed"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Relevant Pages
|
