Re: backupbyname very slow

From: Hajo Ehlers (service_at_metamodul.com)
Date: 09/16/05 

Date: 16 Sep 2005 06:41:11 -0700

Hi Moth,
i think your problem might be the large amount of small files.
To check this you should create a large file or many large file ( 20*1
GB ) and backup them up. Check the time the backup needed or test with

time dd if=/dev/zero of=/dev/rmt0 ibs=1m obs=32k count=1000

If the backup speed is ok the bottleneck should not be the HBA or
Tapedrive or Tape.
BTW: ( Tapes can be bad - Check for write errors )

The point is to get a steady stream of data to the tape drive. If this
will not happen the speed will go down dramaticly.

Solutions:
1)
try to use 'dd' after backup with a large blocksize and conv=sync
( find .. | backup ... | dd of=/dev/rmt0 obs=256k conv=sync )
2)
Pack the small files to larger ones and backup these files. ( If you
must repeat these step do not forget to use after the first one a
nonrewind tape device )

3) Do a test restore.

hth
Hajo

The following Redbook is a section about
http://www.redbooks.ibm.com/redpieces/pdfs/sg246502.pdf

Relevant Pages

  • Re: VTL vs. Backup to Disk
    ... Disk is designated as DASD. ... emulated to provide a complete tape emulation solution. ... The question boils down to backup application support. ... so a good VTL may provide for a better solutions and better ...
    (comp.arch.storage)
  • RE: backup not starting
    ... "The requested media failed to mount" error message when you try to perform ... Backups on Windows Small Business Server 2003 may use more backup media ... If the issue persists, please manually clean the tape driver, and then ... by specifying the same media label name. ...
    (microsoft.public.windows.server.sbs)
  • RE: Backup failed event:
    ... 1.There is actually no tape in the tape device and it is not correctly ... Please checked the HCL list for DLT backup device from our HCL ... your backup media. ... This operation writes a "free media" label on each tape. ...
    (microsoft.public.windows.server.sbs)
  • Re: SBS 2003 Standard Restore from tape
    ... I use the SBS Backup Utility from the Server management console no 3rd party backup software. ... I use the tape driver that comes with SBS 2003 with a seagate dat4 tape drive. ... When i try to do a catalog on these tapes i get the error message "The library is unable to load the media at this time because the drive is in use." ...
    (microsoft.public.windows.server.sbs)
  • Re: [SLE] Backups -- near-line disc and off-line tape
    ... daily tars copied to a 4th server with a tape ... That's actually a good strategy -- you buffer to disc, ... such real-time tape backup is why most people hate tape. ... new $500-600 backup server, or just use an existing server (that doesn't ...
    (SuSE)