Re: [Bacula-users] compression with lto?
On 5/17/23 12:52, Marco Gaiarin wrote: I've LTO tape that work in very dusty environment by at least 6 years. Istead of dust, i've found that setting properly spooling and buffers prevent the spinup/spindown effect, that effectively can be very stressful... Yes, I went to great lengths to try to keep mine streaming and avoid shoe-shining, but with only moderate success. I have had many fewer problems, as well as much better performance, since I abandoned tape and went to disk-to-disk-to-removable-disk (with both of the destination disk stages being RAID). Full backup cycles that used to take 18 hours and two or three media changes, with about a 10% failure rate due to media errors, now take 3 or 4 hours with no media changes and nearly 100% success. However, we are getting further and further off the subject of compression. -- Phil Stracchino Babylon Communications ph...@caerllewys.net p...@co.ordinate.org Landline: +1.603.293.8485 Mobile: +1.603.998.6958 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] compression with lto?
Mandi! Phil Stracchino In chel di` si favelave... > I have to admit I found the cost of the media for the last LTO > generation I used (LTO4) to be secondary to the cost of replacing drive > after drive after drive as they failed, because in my experience LTO > drives fail very quickly outside of a clean-room environment or a sealed > tape library. I've LTO tape that work in very dusty environment by at least 6 years. Istead of dust, i've found that setting properly spooling and buffers prevent the spinup/spindown effect, that effectively can be very stressful... -- La macchina del capo la guida Emilio Fede La macchina del capo la lava Emilio Fede La macchina del capo la parcheggia Emilio Fede ma la benzina gliela paghiamo noi [Dado] ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] compression with lto?
On 5/17/23 11:48, Dr. Thorsten Brandau wrote: I decided to use the softwarecompression instead, as this actually compresses the files. At last it means 1.4:1 for me, which is a lot better than uncompressed backup (LTO9 tapes are very expensive...). I have to admit I found the cost of the media for the last LTO generation I used (LTO4) to be secondary to the cost of replacing drive after drive after drive as they failed, because in my experience LTO drives fail very quickly outside of a clean-room environment or a sealed tape library. -- Phil Stracchino Babylon Communications ph...@caerllewys.net p...@co.ordinate.org Landline: +1.603.293.8485 Mobile: +1.603.998.6958 ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
Re: [Bacula-users] compression with lto?
Bill Arlofski via Bacula-users schrieb am 11.05.23 um 20:45: On 5/10/23 21:49, Dr. Thorsten Brandau wrote: Hi I use an lto-9 drive for backup. I activated hardware compression on the tape (i think) but all the logs of bacula show a tape change at 18TB which should be the native (uncompressed) capacity. From experience I would expect a ratio of at last 1:1.2. Is there any way to make sure to use compression (or as last resort activate software compression)? Hello Thorsten, Of course, with LTO tape drives, you always want to enable hardware compression and disable software compression in Bacula. How that is set on your specific drive(s) I do not know. :) Bacula will just write until it gets an EOT (end of tape) from the tape drive, so the compression you will see is dependent on your dataset. Some tips: In your Director's configuration for the Storage resource which points to the SD's Tape drive (or library with multiple drives), you should set `AllowCompression = no` This will tell the FDs to not try to compress data before sending it to the SD when using this Storage resource in a job, even if you have a `compression = (lzo|gzip|zstd)` in your fileset. For jobs using this Storage, if compression in enabled for the fileset in use, you will see a harmless info log entry in the job logs telling you that "compression is not allowed for this storage device". (or similar) I prefer to enable/disable this in the Director's Storage resource and always enable compression in my filesets so that the same job and fileset, when using a different Director Storage that allows compression, it will automatically "Just Work"™ P.S. You can enable/disable compression in the SD's Devices, but I prefer to set it at what I would call the beginning of the chain in the Director's Storage resource. Home some of this is helpful, Bill Hi Bill I decided to use the softwarecompression instead, as this actually compresses the files. At last it means 1.4:1 for me, which is a lot better than uncompressed backup (LTO9 tapes are very expensive...). Any other setting did not work and from the change rates I have seen the drive did not compress the data (in the autochanger). I have no idea if it is a problem of the autochanger or not. On the other hand, that also reduced my total backuptime quite a bit as less data had to be written and cached... Cheers T ___ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
