Re: LTO 8 Slow write speeds
Gilles Van Vlasselaer <[email protected]>
| Newsgroups | gmane.comp.bacula.user |
|---|---|
| Message-ID | <[email protected]> |
Hi Udo, > Your Maximum File Size ist too small. If you assume 300MB/sec the tape > would stop every 5000/300 seconds to write an EOF mark. That cannot be > fast. Please try at least the amount of data for writing 3 minutes > sustained (Maximum File Size = 54GB). I'll try this once the current copy job is complete, benchmarking the btape speed command using file_size=5 wrote 5GB chunks, which reached the 200MB~/sec mark. > What size are your file volumes? Pool Daily -> Incrementals + daily bacula DB dump +------------+-----------+---------+-----------------+----------+ | volumename | volstatus | enabled | volbytes | volfiles | +------------+-----------+---------+-----------------+----------+ | Catalogs | Used | 1 | 407,715,205,671 | 94 | | Daily-13 | Used | 1 | 953,720,636,816 | 222 | | Daily-10 | Append | 1 | 79,824,581,674 | 18 | | Daily-11 | Used | 1 | 778,609,282,174 | 181 | | Daily-12 | Used | 1 | 573,366,535,214 | 133 | | Daily-0085 | Used | 1 | 408,215,876,761 | 95 | | Daily-0260 | Used | 1 | 460,077,395,998 | 107 | +------------+-----------+---------+-----------------+----------+ Pool Weekly -> Full backups +-------------+-----------+---------+-------------------+----------+ | volumename | volstatus | enabled | volbytes | volfiles | +-------------+-----------+---------+-------------------+----------+ | Weekly-0035 | Used | 1 | 3,224,557,692,497 | 750 | | Weekly-0036 | Used | 1 | 2,323,662,023,874 | 541 | | Weekly-0037 | Append | 1 | 5,563,811,862,205 | 1,295 | | Weekly-0043 | Full | 1 | 202 | 0 | +-------------+-----------+---------+-------------------+----------+ Thank you, - Gilles On 4/8/25 15:13, Udo Kaune wrote: > Am 08.04.25 um 14:18 schrieb Gilles Van Vlasselaer: >> >> Hi all, I'm having issues with write speeds to our LTO drive. Copy >> jobs aren't going over 100 MB/sec, and on average it's around 80 MB/sec. >> >> Using btape speed I was benchmarking the performance on different >> tapes (HW compression on/off, HW encryption on/off), and it reached >> 180-220 MB/sec, depending on the test. Still, it's nowhere near the >> theoretical maximum of the LTO 8 specification. But even reaching the >> benchmark speeds would mean that our job copy time would be halved. >> >> Our Storage Daemon stores all full and incremental backups on a file >> volume. This volume resides on a ZFS pool. I've also benchmarked the >> ZFS pool, and it easily reads continuously over 300 MB/sec. Once a >> month, we issue a Copy Job to the LTO 8 tape. >> >> Bacula DIR and SD run on the same machine, with a Quantum LTO-8 HH >> drive, using Quantum MR-L8MQN-01 tapes. >> >> >> Am I'm missing some important properties in the resources? Any help >> is appreciated. >> >> - Gilles >> >> > > Hi Gilles, > > Your Maximum File Size ist too small. If you assume 300MB/sec the tape > would stop every 5000/300 seconds to write an EOF mark. That cannot be > fast. Please try at least the amount of data for writing 3 minutes > sustained (Maximum File Size = 54GB). > Be aware that you have to wait at least for one complete block to be > read if you are doing a restore. (3 minutes again in our example). > What size are your file volumes? > > Best regards, Udo > > > _______________________________________________ > Bacula-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/bacula-users _______________________________________________ Bacula-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-users