On Tuesday 07 March 2006 14:58, FM wrote: >Hello, > >Do I need a holdingdisk when I using hard drive backup ? > >I have a lots of iowait because of the copy from holding disk to > virtual tape even if the holding disk is on internal SCSI drives and > tapes are on an extrenal SCSI array (using sata drives) > I think the holding disk is still a good idea. It allows the "tapeing" to proceed in the order that the individual DLE's are completed, and to even have them juggled a bit in sequence in the event you are using a priority string in your amanda.conf.
There may well be fragmentation effects to deal with when not using the holding disk since then each DLE would get written in much smaller pieces leading to more severe fragmentation issues. I am not haveing that to a noticeable degree here, and I am using a large (24GB) holding disk. However, when its time to e2fsck that disk, I haven't been aware that fragmentation has ever been over 3%, and even that would be preventable were it practical to make that many partitions, which it isn't. All disks are ext3 formatted here. The holding disk here is not, for obvious reasons, on the same spindle as the vtapes, that would indeed be a "not recommended practice" I believe. It also serves as an emergency backup should something happen to the vtapes disk, a rather important consideration IMO as you can effect a repair of a failed disk before you actually run out of space, in my case even for a 3 or 4 day holiday weekend. Install a new disk, format it, do the mkdirs & labeling, make the link, and amflush it one days worth at a time. No data of importance is lost since my dumpcycle is 4 days here. >thanks ! -- Cheers, Gene People having trouble with vz bouncing email to me should add the word 'online' between the 'verizon', and the dot which bypasses vz's stupid bounce rules. I do use spamassassin too. :-) Yahoo.com and AOL/TW attorneys please note, additions to the above message by Gene Heskett are: Copyright 2006 by Maurice Eugene Heskett, all rights reserved.
