[SunHELP] remote ufsdump

[Brian Hechinger]

> check your scales again... Tape drives are rated at megaBYTES per
> second  networks are rated at megaBITS.... I've saturated a 10baseT
> network backing up to a DDS-2 before.

well, the place i went for reference had the 8mm stuff as 360MB/min so i just
converted that to bits, so the 8mm stuff is correct (for the most part) however
the 4mm stuff is marked as Mbps and to me a small b designates bits not bytes.
so, saying that you have saturated a 10BaseT with DDS-2 i now believe that he
did in fact mean bytes.  thanks!!  i never would have noticed.

> Let's go uncompressed:compressed with AIT-2. One drive will pull
> 6MB/sec:15.6MB/sec [their compression numbers]*. Let's translate to
> networking stats, that's 48Mb/sec:124.8Mb/sec. There you go, your 100Mb
> connection is toast. If you use more then one drive then your really going
> to blow it.

here, for some reason i thought the compression was happening on the client
not the drive, so i got myself all confused, i appologize.  you are in fact
correct.  thanks for the correction.

> In setting up a network backup server I recomend a gigE port for the server.
> I remember Cisco makes a switch with 100Mb/sec ports and 1 gigE port. This
> works well, except the damn Sun cards can't auto negotiate with the switch
> (bastards!). This works well 'till you have 8 drives, then, well, at that
> point your going to be buying an E450 or larger just to do backups
> (presuming your going to 8 drives at once durring the backup).

this is an excellent recommendation, and if this is not enough (you need 24/7
availability with no backup windows) then a secondary ethernet network just
for backups is a great idea as well (i've set this up at several places, makes
people VERY happy)

> *do you belive their compression numbers? I'll let you know how AIT-2 does
> with our data when budget is free again.

i don't doubt the compression numbers, everyone i've ever heard talk about AIT
RAVES about the compression rates they get as compared to their old technology.

-brian