SVCNet wrote: short answer: YES
on the notes:
so inisip mong may sira, o hindi na sapat ang laki ng SSD mo kaya mo pinalitan
ano ba ang proseso ng "writeback"?
ang "writeback-ssd" ay ang virtual memory sa HARDISK ng client mo
ang virtual memory ay nag i store ng KASALUKUYANG datos mo kung hindi sapat sa RAM mo
ibig sabihin HINDI MO NA KAILANGAN ang mga datos na yuin after ng gawain mo
dahil diskless ka at walang hardisk, yung "writeback ssd" ang ginagawa nyang virual memory
ilang dahilan ng pagloloko ng writeback-ssd mo
1) maaring hindi talaga sapat ang laki ng ssd mo. 128GB ang kailangan sa 25 clients
2) sapat ang laki ng ssd mo pero hindi na sapat ang natitirang "buhay"
3) matakaw sa "virtual files" ang clients mo. (install cheats, downliad, update)
4) may sumasabotahe sayo para punuin sadya ang writeback ssd mo
Ang write-back ay hindi virtual memory. Pag sinabi mo virtual memory ito yung memory (physical + paged o swap sa linux) na in-asemble ng OS. Ang virtual memory ay naka-designed na working memory at hindi for permanent storage in contrast with "write-back" device.
Write-back na sinasabi natin sa ccboot is actually a differencing disk. Ang term na write-back is a writing mechanism na ang ibig sabihin, "store mo muna sa memory at isulat mo nalang later on sa 'writeback device'". Kung mapapansin mo - may single, master image na shared across all nodes. Read-only lang ito. Any form of reads by nodes are written on the "write-back" device, having their own identifier (filename). Kaya habang tumatagal, bumagal ang performance kasi nga for every read/write, the OS has to perform comparison against its master image. Sa Linux, may image format called qcow. Kapag matal mo nang gamit ang differncing disk at gusto mo i-incorpate yung changes into the master image, pwede. Tapos, remove mo all the differencing copies of each node, umpisa uli sa updated master image.
"Write-back" device are therefore going to suffer to frequent writes.
Baka ang ibig sabihin mo ay buffering. For every write request to a permanent storage, the OS can delay the write (more performant, but can cause data loss) or write it straight away (mas mabagal) depening on how it is configured.