Re: D2D on AIX
2004-09-21 19:20:31
How does TSM access the data on file volumes? Does it keep an offset of the
start of every file or aggregate?
If it does, then yes we could skip to the start of each file or aggregate. If
it does not, then we need to read through the volume to find the file we are
going to restore. Where we have a large number of concurrent restores
happening, this could cause performance issues on the array.
Now TSM has some smarts on later technology tape drives that have block
addressability and on-cartridge memory and can find a spot on the tape quickly,
but does this translate to file volumes?
Regards
Steve.
>>> lau AT VTCAT.CC.VT DOT EDU 22/09/2004 4:49:55 >>>
True. Seek time is tiny compared to tape mounts. I am just concerned that
the TSM db has to keep track of thousands of volume. How much will it increase
the size of the db. Ours is already 90G at 70% utilized.
Eliza
>
> ==> In article <200409211619.i8LGJsbf018132 AT vtcat.cc.vt DOT edu>, Eliza
> Lau <lau AT VTCAT.CC.VT DOT EDU> writes:
>
> > What is the recommended volume size. I have seen someone mentioned 5G, but
> > then the number of volumes will explode from about 800 (current # of 3590
> > primary tapes) to thousands.
>
> Consider, this doesn't really cost you much. Seek time in a directory of
> thousands of files is still tiny compared to tape behavior.
>
> I probably wouldn't go as low as 5G, but 10G (much less than the average size
> of my 3590 vols) seems pretty reasonable to me. 20G is getting big, from my
> perspective.
>
>
>
> > How about keeping the staging space so clients backup to staging then
> > migrate to FILE volumes. Then every volume will be filled up.
>
>
> I like this, too.
>
>
> - Allen S. Rout
>
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- Re: D2D on AIX, (continued)
- Re: D2D on AIX, Rushforth, Tim
- Re: D2D on AIX, Rushforth, Tim
- Re: D2D on AIX, Johnson, Milton
- Re: D2D on AIX, Johnson, Milton
- Re: D2D on AIX, Rushforth, Tim
- Re: D2D on AIX, Eliza Lau
- Re: D2D on AIX,
Steve Harris <=
Re: D2D on AIX, Thach, Kevin G
Re: D2D on AIX, Richard Rhodes
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