Guy,

Are you also using amanda software compression?

Using compression on the holding disk is probably just a waste of CPU as the data is compressed once and decompressed once, but if it the only way it can fit in the holding disk.

If you use amanda software compression, then the data is compressed on holding disk and on tape.

Jean-Louis

On 05/01/2013 01:10 PM, Guy Sisalli wrote:
I'm attempting to commit 7 TB of text to tape. It's presently stored in
a natively gzip-9 compressed zvol, weighing in at 1.7 TB.

My holding area is 5 TB, and is set to a native gzip-5 compression.

The functional difference between gzip-5 and gzip-9 is not very much:
Level 9 compression has a 4-8% advantage over level 5. The entire DLE
(taken as files, not a snapshot) should fit quite comfortably in my
holding area. It didn't!

I watched my holding area balloon to 4 TB and keep right on going, as if
it wasn't compressing at all. Is there any scenario in which this might
happen? Would you recommend against a setup like the one I've described?
I'm happy to offer any details needed, but this is probably a good start:

Source:

NAME            PROPERTY              VALUE                  SOURCE
zulu01/keyRepo  type                  filesystem             -
zulu01/keyRepo  creation              Tue Jan  8 13:48 2013  -
zulu01/keyRepo  used                  1.74T                  -
zulu01/keyRepo  available             6.60T                  -
zulu01/keyRepo  referenced            1.74T                  -
zulu01/keyRepo  compressratio         4.65x                  -
zulu01/keyRepo  mounted               yes                    -
zulu01/keyRepo  quota                 none                   default
zulu01/keyRepo  reservation           none                   default
zulu01/keyRepo  recordsize            128K                   default
zulu01/keyRepo  mountpoint            /tank/datastore        default
zulu01/keyRepo  sharenfs              off                    default
zulu01/keyRepo  checksum              on                     default
zulu01/keyRepo  compression           gzip-9                 local

Hold:

NAME  PROPERTY              VALUE                  SOURCE
hold  type                  filesystem             -
hold  creation              Fri Dec  7 10:34 2012  -
hold  used                  257M                   -
hold  available             5.35T                  -
hold  referenced            243M                   -
hold  compressratio         1.00x                  -
hold  mounted               no                     -
hold  quota                 none                   default
hold  reservation           none                   default
hold  recordsize            128K                   default
hold  mountpoint            /hold                  default
hold  sharenfs              off                    default
hold  checksum              on                     default
hold  compression           gzip-5                 local


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