Vrestore - generates parasite load on dsk0

[Alexey Borchev]

The system is ES40 4x666MHz, 16 GB, 5.1A pk3
Storage is RA7000, SDLT tape.
Restore starts OK for 5-10 minites - 8 MB/s traffic to destination disk - raid from RA7000, HSZ70). No other activity.

After this time, I see:
- Traffic to destination disk about 4 MB/s
- Traffic about 4 MB/s on dsk0 (system disk, /, /usr, /var, swap, nothing else - internal, not RA7000)
- System responce to keyboard is SLOW.
- >10 GB of free memory (Oracle is down)
- No swap usage (1 page used).
- No other users & activity
- df shows that free space in /, /usr, /var does not change over time.
- The effect is stable & reproducible.

I belive that SDLT is faster than RA7000.

If any ideas how to stop this traffic on dsk0?

[Orrin]

Hi,

Are you using compression to back up the data... try backing up with no compression and restoring in the same manner...

we had response issues and noticed a significant improvement when we changed over to uncompressed.

ie. try using tape?_d0 or tape?_d2 and try...

Hope it helps anyway.

[Ralf Puchner]

have a look into the binary.errlog for possible hardware problems (SCSI, CPU).

I'm not understanding why the keyboard response would be slow if copying data.

BTW: df is not a valid indicator of filling filesystems. Please us showfdmn instead, giving the real free space.

What kind of swap algorithm is used?